API_POLICIES.md

@@ -0,0 +1,20 @@
+---
+title: API Policies
+last_modified: 2026-10-27
+---
+
+A value in an API response is never a string with a label or unit in it. A value
+of a native type is sent as that type, and its unit goes in the field name, for
+example `_ms`.
+
+Wrong:
+
+```json
+{ "execution_time": "0 ms" }
+```
+
+Right:
+
+```json
+{ "execution_time_ms": 0 }
+```

README.md

@@ -9,19 +9,38 @@ table in real time. It works like this:
 
 ## Rationale
 
-RIPE RIS Live streams the BGP updates that RIPE's route collectors receive, as
+RouteWatch exists to serve our other services as an internal API for information
-they happen, from the moment a client connects. It reports changes, not the
+about IP addresses.
-routing table they add up to, so it cannot say which AS an IP address is routed
-to now or which routes a prefix has. RouteWatch applies the feed's updates to a
-routing table that it keeps in memory, with a copy in its own SQLite database.
-It answers IP-to-AS lookups and prefix pages from that table.
 
-The feed sends no table when a client connects. So the routing table holds only
+RouteWatch follows BGP routing table updates from RIPE RIS Live. RIS Live
-the routes announced since RouteWatch first started. An IP-to-AS lookup finds
+streams the updates that RIPE's route collectors receive, as they happen, from
-nothing for an address whose routes have not been announced since then. The
+the moment a client connects. It reports changes, not the routing table they add
-routing table also misses updates RouteWatch drops when it falls behind, and
+up to. RouteWatch applies those changes to a routing table that it keeps in
-updates sent while it is stopped. So a lookup or a prefix page can show a route
+memory, with a copy in its own SQLite database. From that table, RouteWatch sees
-the feed has withdrawn.
+directly:
+
+- which AS each IP address is routed to
+- which announced prefix holds each IP address, and how big that prefix is
+
+RouteWatch adds details of each AS from WHOIS, the public directory of the
+internet registries. The details include the organisation that holds the AS.
+RouteWatch keeps them in its database and looks them up again once they are 30
+days old. An IP lookup answers from those stored details and never waits for
+WHOIS.
+
+So our own services can ask RouteWatch about an IP address, instead of each
+working it out for itself.
+
+RIS Live sends no routing table when a client connects. So the routing table
+holds only the routes announced since RouteWatch first started. An IP lookup
+finds no route for an address until a prefix that holds it is announced. The
+routing table also misses these updates:
+
+- those sent while RouteWatch is stopped
+- those that RouteWatch drops when it falls behind
+
+A lookup or a prefix page can therefore show a route that has since been
+withdrawn.
 
 ## Features
 
@@ -70,12 +89,56 @@ one of its peers sends an update.
 - `GET /` - Home page (HTML): headline figures, lookups by AS number and by IP
   address, and a search of AS names. A card shows the `curl` command that looks
   up the visitor's own address at `/ip/{addr}`, and that command's live answer.
+  Other cards show figures of the routing table, with links to the AS and prefix
+  pages:
+    - the newest and the oldest kept route, with its prefix, origin AS and time
+    - the AS last seen in an AS path most recently, and the one last seen
+      longest ago
+    - the AS that originates the most prefixes
+    - how many ASes originate a single prefix, and the most recently updated of
+      them
+    - the number of bogon announcements, linked to `/bogons`
+    - the number of prefixes with more than one origin AS, linked to
+      `/multiple-origins`
+    - well-known networks, such as Apple, Google, Cogent and MIT, each with its
+      number of prefixes and the time of its newest kept route, newest first
+
+    RouteWatch works these figures out once a minute, so they can be a minute
+    old.
+
+- `GET /bogons` - The bogon announcements (HTML): the routes whose prefix or
+  origin AS is reserved. A prefix is reserved when it lies inside one of these:
+    - a block that the IANA special-purpose address registries mark as not
+      globally reachable
+    - the multicast space, `224.0.0.0/4` and `ff00::/8`, which the IANA IPv4 and
+      IPv6 address space registries list as Multicast
+
+    A reserved AS number is one of these:
+    - an AS number for private use or for documentation
+    - `AS23456`
+    - the last AS number of the 16-bit or the 32-bit range
+
+    Address space and AS numbers that the IANA has not handed out yet are not
+    counted. Each row shows the prefix, the origin AS, the number of peers and
+    why it is a bogon. The page shows at most 1,000 rows, in prefix order, and
+    says how many there are in all.
+
+- `GET /multiple-origins` - The prefixes announced by more than one origin AS
+  (HTML). Each row shows the origin ASes and how many peers carry the prefix
+  with each. Like `/bogons`, it shows at most 1,000 rows, in prefix order, and
+  says how many there are in all.
 - `GET /status` - HTML status dashboard, which reads `/api/v1/stats`
 - `GET /status.json` - JSON statistics: feed, memory, database and route
   figures. The route figures come from the routing table. `oldest_route` and
   `newest_route` are the times of the oldest and the newest kept routes.
   `origins_without_kept_route` counts, across all prefixes, the origin ASes that
-  have no kept route.
+  have no kept route. Other figures include these:
+    - `uptime_seconds`: the number of seconds since the RIS Live feed last
+      connected, or 0 when it has never connected
+    - `memory_usage_bytes`: the size of the Go heap in use, in bytes
+    - `whois_stats.current_interval_seconds`: the WHOIS fetcher's wait between
+      two fetches, in seconds, which can include a fraction of a second
+
 - `GET /.well-known/healthcheck.json` - Health check (JSON): 200 when the
   database answers and the RIS Live feed is connected, otherwise 503;
   `data.status` is `ok` or `error` and `data.checks` says which check failed
@@ -98,20 +161,45 @@ one of its peers sends an update.
 ### API v1
 
 - `GET /api/v1/stats` - The `/status.json` figures plus connection, garbage
-  collector, stream and handler queue statistics. `stream.route_churn_per_min`
+  collector, stream and handler queue statistics. `connection_duration_seconds`
-  is the number of prefix announcements and withdrawals, from all peers, in the
+  is the number of seconds the RIS Live feed has been connected, or null while
-  last full clock minute.
+  it is not connected. `stream.route_churn_per_min` is the number of prefix
+  announcements and withdrawals, from all peers, in the last full clock minute.
 - `GET /api/v1/ip/{ip}` - Looks up each address. `{ip}` is an IP address, a host
   name, or a comma-separated list of at most 10 of these. `results` has one
-  entry for each address, with:
+  entry for each address. Every entry has the same fields:
-    - `ip` and `ptr`: the address and its PTR names
+    - `ip`: the address
-    - `netblock` and the fields beside it: the most specific prefix that holds
+    - `ptr`: the address's PTR names, or an empty list when it has none
-      the address, and its origin AS with that AS's WHOIS details. For a prefix
+    - `blocklists`: the public blocklists the address is on (see Blocklists), or
-      with several origin ASes, `asn` is the one that most peers carry.
+      an empty list when it is on none
-      `last_seen` is the time of the prefix's newest kept route.
+
-    - `blocklists`: the public blocklists the address is on (see Blocklists)
+    Every other field is about the address's live route. Each is null when the
+    address has no live route. The fields about the route:
+    - `netblock`: the most specific prefix that holds the address
+    - `mask_length`: the netblock's mask length
+    - `ip_version`: the netblock's IP version, 4 or 6
+    - `num_peers`: the number of peers that carry the netblock
+    - `asn`: the origin AS that the most peers carry the netblock with
+    - `num_origins`: the number of origin ASes that peers carry the netblock
+      with
+    - `origin_asns`: those origin ASes, in AS number order
+    - `first_seen`: when RouteWatch first saw the netblock, or null when the
+      database has not stored the netblock yet
+    - `last_seen`: the time of the netblock's newest kept route, or null when
+      the netblock keeps no route
+
+    The fields about the AS in `asn` come from the database. Each is also null
+    when the database does not have it:
+    - `handle`: the AS's handle
+    - `description`: the AS's description
+    - `as_name`: the AS's name in its WHOIS details
+    - `org_name`: the name of the organisation that holds the AS
+    - `org_id`: the organisation's ID at its registry
+    - `address`: the organisation's postal address
+    - `country_code`: the organisation's country code
+    - `abuse_email`: the address that takes abuse reports for the AS
+    - `rir`: the regional internet registry of the AS
 
-    An address with no live route has a result without the route and AS fields.
     Of the addresses a host name resolves to, only public ones are looked up. A
     name with none, such as one that resolves to a private address, is reported
     as `host name has no public address`, without its addresses. `errors` has
@@ -145,10 +233,16 @@ one of its peers sends an update.
     missing, empty or only spaces answers 400.
 
 A JSON answer is `{"status": "ok", "data": ...}`, or for an error
-`{"status": "error", "error": {"msg": ..., "code": ...}}`, and carries an
+`{"status": "error", "error": {"msg": ..., "code": ...}}`. The health check is
-`@meta` object with the time zone, the API version and the time the request
+the exception: its 503 answer is also `{"status": "ok", "data": ...}`, with
-took. The health check is the exception: its 503 answer is also
+`error` in `data.status`. Every JSON answer also carries an `@meta` object:
-`{"status": "ok", "data": ...}`, with `error` in `data.status`.
+
+- `time_zone`: always `UTC`
+- `api_version`: `1`
+- `execution_time_ms`: the number of milliseconds the request took
+
+Every value with a unit is a number whose field name ends in the unit, such as
+`_ms`, `_seconds` or `_bytes`.
 
 A request that runs past its time limit answers 504: the limit is 30 seconds,
 and 4 seconds for the database reads behind `/status.json` and `/api/v1/stats`.
@@ -158,11 +252,17 @@ originates no prefix and has no record in the database or in the AS list built
 into RouteWatch. AS 0 always answers 404, because it means no known origin. The
 AS name search never lists it. A prefix with no live route answers 404 too. The
 HTML pages give these errors as plain text. Under `/api/v1` and `/ip/`, a path
-no route matches answers 404 with the message `Not found`, and `POST`, `PUT`,
+that matches no route answers 404 with the message `Not found`. A request with
-`PATCH`, `DELETE`, `OPTIONS`, `TRACE` or `CONNECT` answers 405 with
+`POST`, `PUT`, `PATCH`, `DELETE`, `OPTIONS`, `TRACE` or `CONNECT` answers 405
-`Method not allowed`. A 500 answer says only `Internal server error`, and a host
+with `Method not allowed` on these routes:
-name that does not resolve only `could not resolve host name`; the detail goes
+
-to the log.
+- the routes under `/api/v1` and `/ip/`
+- `/status.json`
+- `/.well-known/healthcheck.json`
+
+A 500 answer says only `Internal server error`. The error for a host name that
+does not resolve says only `could not resolve host name`. The detail goes to the
+log.
 
 Every answer carries `Strict-Transport-Security`, `Content-Security-Policy`,
 `X-Frame-Options`, `X-Content-Type-Options`, `Referrer-Policy` and
@@ -173,10 +273,15 @@ so each answer's policy names a random nonce made for that answer, and the
 browser applies or runs only the blocks that carry it. The pages therefore use
 no `style` attributes, which a nonce cannot cover.
 
-An origin AS of 0 (`origin_asn` in a route, `asn` in an IP lookup, the key `0`
+An origin AS of 0 means the route has no known origin. Its AS path ends in an AS
-in a prefix's `origins`) means the route has no known origin: its AS path ends
+set of several members, any of which may have originated it. The 0 appears in
-in an AS set of several members, any of which may have originated it. The pages
+these fields:
-show such a route as having no known origin.
+
+- `origin_asn` in a route
+- `asn` and `origin_asns` in an IP lookup
+- the key `0` in a prefix's `origins`
+
+The pages show such a route as having no known origin.
 
 ## Blocklists
 
@@ -248,6 +353,7 @@ routewatch/
 │   └── streamdumper/       # Debug utility for raw stream output
 ├── internal/
 │   ├── blocklist/          # Public IP blocklists: downloads and lookups
+│   ├── bogon/              # Reserved prefixes and AS numbers
 │   ├── routewatch/         # Core application logic
 │   ├── server/             # HTTP server and handlers
 │   ├── database/           # SQLite storage layer
@@ -430,19 +536,29 @@ Configuration is handled via environment variables and OS-specific paths:
 | `XDG_DATA_HOME`    | `/var/lib` (in the Docker image) | Base of the state directory; must be an absolute path       |
 | `GOMEMLIMIT`       | `2560MiB` (in the Docker image)  | Go soft memory limit; see Memory                            |
 | `MALLOC_ARENA_MAX` | `2` (in the Docker image)        | glibc malloc arena cap, a positive whole number; see Memory |
-| `TRUSTED_PROXIES`  | (empty)                          | Addresses and CIDR ranges of trusted proxies; see below     |
+| `TRUSTED_PROXIES`  | the RFC 1918 ranges              | Addresses and CIDR ranges of trusted proxies; see below     |
 
 A variable that is set to an invalid value stops the start with an error and a
-non-zero exit. An empty variable counts as unset.
+non-zero exit. An empty variable counts as unset. `TRUSTED_PROXIES` is the one
+exception: set but empty, it makes the server trust no proxy.
 
-`TRUSTED_PROXIES` lists the reverse proxies whose `X-Forwarded-For` the server
+`TRUSTED_PROXIES` names the reverse proxies whose `X-Forwarded-For` the server
-believes, comma-separated, such as `10.0.0.0/8,192.0.2.1`. For a request from
+believes:
-one of them, the request log and `/ip/` use the last address in
+
-`X-Forwarded-For` that is not a trusted proxy: each proxy adds the address it
+- When it is not set, the server trusts the private ranges of RFC 1918:
-received the request from to the end, so the entries before it are whatever the
+    - `10.0.0.0/8`
-client sent. For a request from any other address they use the address the
+    - `172.16.0.0/12`
-request came from, whatever forwarding headers it carries. `X-Real-IP` and
+    - `192.168.0.0/16`
-`True-Client-IP` are not read.
+- When it lists addresses and CIDR ranges, comma-separated, such as
+  `10.0.0.0/8,192.0.2.1`, the server trusts those instead.
+- When it is set but empty (`TRUSTED_PROXIES=`), the server trusts no proxy.
+
+For a request from a trusted proxy, the request log and `/ip/` use the last
+address in `X-Forwarded-For` that is not a trusted proxy. Each proxy adds the
+address it received the request from to the end, so the entries before it are
+whatever the client sent. For a request from any other address they use the
+address the request came from, whatever forwarding headers it carries.
+`X-Real-IP` and `True-Client-IP` are not read.
 
 State directory (the database and the blocklist copies):
 
@@ -536,12 +652,11 @@ What the [upaas](https://git.eeqj.de/sneak/upaas) app needs:
 
 - Container port: `8080`.
 - Volume: one, at container path `/var/lib/berlin.sneak.app.routewatch`.
-- Environment: `TRUSTED_PROXIES`, set to the address the reverse proxy in front
+- Environment: nothing. The server trusts a reverse proxy at an RFC 1918 address
-  of the app connects from, as the container sees it; without it the request log
+  without `TRUSTED_PROXIES` (see Configuration). Set it only when the proxy
-  and `/ip/` give the proxy's address for every request. Nothing else is needed:
+  connects from any other address. Leave `XDG_DATA_HOME`, `GOMEMLIMIT` and
-  leave `XDG_DATA_HOME`, `GOMEMLIMIT` and `MALLOC_ARENA_MAX` at the image's
+  `MALLOC_ARENA_MAX` at the image's values. `DEBUG=routewatch` is optional and
-  values. `DEBUG=routewatch` is optional and adds the `System stats` memory line
+  adds the `System stats` memory line to the log.
-  to the log.
 - Memory Limit: `5g`, the 5 GiB limit from Memory above. upaas sets no swap
   limit, so on a host with swap Docker allows the same amount of swap again.
 - Health check: the image's `HEALTHCHECK` requests

REPO_POLICIES.md

@@ -1,6 +1,6 @@
 ---
 title: Repository Policies
-last_modified: 2026-10-18
+last_modified: 2026-10-27
 ---
 
 This document covers repository structure, tooling, and workflow standards. Code
@@ -12,6 +12,7 @@ style conventions are in separate documents:
 - [JavaScript](https://git.eeqj.de/sneak/prompts/raw/branch/main/prompts/CODE_STYLEGUIDE_JS.md)
 - [Python](https://git.eeqj.de/sneak/prompts/raw/branch/main/prompts/CODE_STYLEGUIDE_PYTHON.md)
 - [Go HTTP Server Conventions](https://git.eeqj.de/sneak/prompts/raw/branch/main/prompts/GO_HTTP_SERVER_CONVENTIONS.md)
+- [API Policies](https://git.eeqj.de/sneak/prompts/raw/branch/main/prompts/API_POLICIES.md)
 
 ---
 
@@ -174,27 +175,32 @@ style conventions are in separate documents:
   `script/cibuild`. `script/lint`, `script/test`, `script/cibuild` and
   `script/docker` are the four, and there is no fifth — `script/check` runs the
   two gate phases and `script/fmt-check`, and builds no image of its own. In
-  every stage of the `Dockerfile`, `ARG CACHEBUST` comes right after the steps
+  every stage of the `Dockerfile`, every step that lints, tests or compiles
-  that install system packages and download Go's modules, or right after `FROM`
+  comes after `ARG CACHEBUST`. `ARG CACHEBUST` comes right after these steps:
-  in a stage with neither, and every step that lints, tests or compiles comes
+    - the steps that install system packages
-  after it. A step that installs anything else as well, such as a
+    - the steps that download Go's modules
-  `script/bootstrap` that also installs node packages, comes after it too. A new
+    - the step that runs `script/bootstrap` to install a Python `test` phase's
-  value reruns every `RUN` step after that line; `COPY` steps are compared by
+      packages from `Pipfile.lock`
-  content and need nothing. Docker keeps the layers above the line until the
+
-  base image, their own lines or the files they copy change. A stage without the
+    A stage with none of these steps declares `ARG CACHEBUST` right after
-  `ARG` line is served from cache on an unchanged tree, so a repository
+    `FROM`. A step that installs anything else as well, such as a
-  re-vendors the scripts and adds the `ARG` lines in one commit. The scripts do
+    `script/bootstrap` that also installs node packages, comes after it too. A
-  not pass `--no-cache`: it reruns every step too, but it also builds the layers
+    new value reruns every `RUN` step after that line; `COPY` steps are compared
-  above the line again and empties every cache mount, so Go's build cache and
+    by content and need nothing. Docker keeps the layers above the line until
-  golangci-lint's, which the canonical Go `Dockerfile` below mounts so that they
+    the base image, their own lines or the files they copy change. A stage
-  survive between check builds, would start empty every time. A bare
+    without the `ARG` line is served from cache on an unchanged tree, so a
-  `docker build .` is not evidence that anything ran: a sub-second build
+    repository re-vendors the scripts and adds the `ARG` lines in one commit.
-  reporting success is a cache hit, not a result. Never invalidate by pruning —
+    The scripts do not pass `--no-cache`: it reruns every step too, but it also
-  `docker builder prune` and friends destroy a build cache shared with every
+    builds the layers above the line again and empties every cache mount, so
-  other build on the host. When a check is added or changed, prove it works by
+    Go's build cache and golangci-lint's, which the canonical Go `Dockerfile`
-  planting a defect it must catch and watching the run fail on it, then revert
+    below mounts so that they survive between check builds, would start empty
-  the defect. A green run alone shows neither that the check ran nor that it
+    every time. A bare `docker build .` is not evidence that anything ran: a
-  covers what it should.
+    sub-second build reporting success is a cache hit, not a result. Never
+    invalidate by pruning — `docker builder prune` and friends destroy a build
+    cache shared with every other build on the host. When a check is added or
+    changed, prove it works by planting a defect it must catch and watching the
+    run fail on it, then revert the defect. A green run alone shows neither that
+    the check ran nor that it covers what it should.
 
 - **The gate phases are separate stages, and the build stage depends on both.**
   The lint phase is based on the `golangci/golangci-lint` image (pinned by
@@ -309,6 +315,9 @@ style conventions are in separate documents:
           a package's findings only when the package's files and those of every
           package it imports, `go.mod`, the linters and their settings in
           `.golangci.yml`, and the golangci-lint version are all unchanged.
+        - In a Python `test` phase, the layer of the step that runs
+          `script/bootstrap` to install the packages from `Pipfile.lock`, as
+          described for that phase below.
     - If the project uses `//go:embed` directives that reference build artifacts
       (e.g. a web frontend compiled in a separate stage), the lint phase must
       create placeholder files so the embed directives resolve. Example:
@@ -363,6 +372,67 @@ style conventions are in separate documents:
       `--build-arg VERSION=...`, as `script/docker` and `script/cibuild` already
       do.
 
+- **A Python `test` phase that installs its packages from `Pipfile.lock` does it
+  above `ARG CACHEBUST`, so check builds keep them.** The steps are
+  `COPY script/ script/`, `COPY Pipfile Pipfile.lock ./` and
+  `RUN script/bootstrap`, with `ARG CACHEBUST` right after them. Docker keeps
+  what that `RUN` installed until the base image, `script/`, `Pipfile`,
+  `Pipfile.lock` or a line up to and including the `RUN` changes. The tests run
+  after `ARG CACHEBUST`, on every check build. In every other stage, a step that
+  installs Python packages comes after `ARG CACHEBUST`.
+    - When `script/bootstrap` runs in that step, it installs nothing beyond
+      system packages, pipenv and its dependencies, and the packages from
+      `Pipfile.lock`. It installs no Python there: the tests use the base
+      image's Python, which the image's hash pins. If it installs anything else
+      there, the step goes after `ARG CACHEBUST`.
+    - Every external reference must be pinned by hash, so `script/bootstrap`
+      installs pipenv and its dependencies by hash. It does so with
+      `pip install --require-hashes -r` and a requirements file in `script/`
+      that lists each of them with `==` and its `--hash`. pip refuses to install
+      a dependency the file does not list.
+    - It then runs `pipenv install --deploy`, with `--dev` when the tests need
+      the development packages. `--deploy` installs only what `Pipfile.lock`
+      names, checks every package against the lockfile's hashes, and fails when
+      the lockfile is out of date with `Pipfile`.
+    - A kept layer holds nothing a new install would refuse: pip checked pipenv
+      and its dependencies, and pipenv checked the lockfile's packages, against
+      their hashes. pipenv creates its virtual environment with the `virtualenv`
+      package. The packages that `virtualenv` adds come from wheels inside that
+      package, so the hash pip checked for it covers them. Two things in the
+      layer are not fixed by a hash. A package with no ready-built wheel for the
+      image is built from source. pip downloads the build tools without a hash
+      check, so a kept layer's build of such a package may differ from a new
+      one. And system packages keep the versions the package manager gave when
+      the layer was built; a new install may get newer ones.
+    - As with Go's modules, the packages are kept in a layer, not a cache mount.
+      A cache mount is shared by every build on the host, and nothing checks its
+      files again.
+
+    In this example, `script/bootstrap` finds `make` and `git` already
+    installed, installs pipenv and its dependencies by hash, and runs
+    `pipenv install --dev --deploy`:
+
+    ```dockerfile
+    # Test phase. The 90-second timeout covers both pytest runs.
+    # python:3.x-slim, YYYY-MM-DD
+    FROM python@sha256:... AS test
+    # make and git are base tools that script/bootstrap installs when they
+    # are missing. Installed here, they stay in their own layer when
+    # script/ changes.
+    RUN apt-get update \
+        && apt-get install -y --no-install-recommends make git \
+        && rm -rf /var/lib/apt/lists/*
+    WORKDIR /app
+    COPY script/ script/
+    COPY Pipfile Pipfile.lock ./
+    RUN script/bootstrap
+    ARG CACHEBUST
+    COPY . .
+    RUN timeout 90 sh -c 'pipenv run pytest || { \
+            echo "--- Rerunning with -v for details ---"; \
+            pipenv run pytest -v; exit 1; }'
+    ```
+
 - Every repo should have a Gitea Actions workflow (`.gitea/workflows/`) that
   runs `script/cibuild` on push, and checks out the repo as its only other step,
   with `persist-credentials: false`: `script/cibuild` needs no token, and

TODO.md

@@ -35,6 +35,44 @@ tested.
 
 # Completed Steps
 
+- 2026-10-27: README "Rationale" says why RouteWatch exists: to answer our other
+  services' questions about IP addresses, from its own routing table and the
+  WHOIS details it keeps. It still says what RIS Live does not give (closes
+  #204)
+- 2026-10-27: every JSON answer carries `@meta`. A panic on a JSON route answers
+  500 with the JSON error body. `/status.json` and the health check answer 405
+  with the JSON error body to any method they do not take. The 500 and the 405
+  used to have an empty body. The home page's IP lookup shows the whole JSON
+  answer, `@meta` included. It used to show only the answer's `data`, or only
+  the message of an error answer. A test checks `@meta` on every JSON route, in
+  its successes and its errors (closes #201)
+- 2026-10-27: every value in a JSON answer that has a unit is a number, with the
+  unit at the end of its field name. `@meta.execution_time` is now
+  `execution_time_ms`. The stats' `uptime`, `connection_duration` and
+  `memory_usage` are now `uptime_seconds`, `connection_duration_seconds` and
+  `memory_usage_bytes`. `whois_stats.current_interval` is now
+  `current_interval_seconds`. They used to be strings such as "12 ms",
+  "1h18m34s" or "1.1 GB". `connection_duration_seconds` is null while the feed
+  is not connected. `API_POLICIES.md` is vendored from `sneak/prompts`, and
+  `REPO_POLICIES.md` re-vendored (closes #199)
+- 2026-10-27: every result of the IP lookup has the same fields. A field without
+  a value is null. It used to be left out. An address with no live route has
+  every route and AS field set to null, and `ptr` is an empty list when there
+  are no PTR names. New fields give the number of origin ASes of the netblock,
+  in `num_origins`, and which they are, in `origin_asns` (closes #200)
+- 2026-10-27: with `TRUSTED_PROXIES` unset, the server trusts reverse proxies at
+  the private addresses of RFC 1918. `/ip/`, the home page's `curl` card and the
+  request log then give the client's address from `X-Forwarded-For`. They used
+  to give the proxy's address. A list in `TRUSTED_PROXIES` replaces the default,
+  and `TRUSTED_PROXIES` set but empty trusts no proxy (closes #198)
+- 2026-10-27: the home page has cards with figures of the routing table: the
+  newest and oldest kept route, the newest and oldest updated AS, the AS with
+  the most prefixes, the ASes with a single prefix, and fifteen well-known
+  networks. Two cards count the bogon announcements and the prefixes with more
+  than one origin AS, and link to the new pages `/bogons` and
+  `/multiple-origins` that list them. A new package, `internal/bogon`, tells
+  which prefixes and AS numbers are reserved. The server works the figures out
+  once a minute (closes #154)
 - 2026-10-27: the per-peer route tables are gone, with the code that wrote,
   counted and read them. The prefix handler applies each update to the routing
   table in memory and writes the table's changes every second. It also stores

internal/bogon/bogon.go

@@ -0,0 +1,202 @@
+// Package bogon tells whether a prefix or an AS number is reserved: set aside
+// for a special purpose, so that no network should announce it on the
+// internet. A route is a bogon announcement when its prefix is reserved or its
+// origin AS is.
+//
+// Most reserved prefixes come from the IANA special-purpose address registries
+// for IPv4 and IPv6. The two multicast blocks, 224.0.0.0/4 and ff00::/8, come
+// from the IANA IPv4 and IPv6 address space registries. The reserved AS
+// numbers come from the IANA special-purpose AS numbers registry:
+//   - the AS numbers for private use
+//   - the AS numbers for documentation
+//   - AS 23456, which stands in for a 32-bit AS number
+//   - the last AS number of the 16-bit and of the 32-bit range
+//
+// Address space and AS numbers that the IANA has not handed out yet are not
+// counted.
+package bogon
+
+import (
+	"net/netip"
+	"strconv"
+)
+
+// Prefix returns why prefix is reserved, and true, when it lies inside a
+// reserved block. The most specific registry block that holds prefix decides,
+// because some blocks that may be announced lie inside reserved ones. It
+// returns "" and false when prefix is not reserved.
+func Prefix(prefix netip.Prefix) (string, bool) {
+	var holder *block
+
+	for i, b := range registryBlocks {
+		inside := b.prefix.Bits() <= prefix.Bits() && b.prefix.Contains(prefix.Addr())
+		if inside && (holder == nil || b.prefix.Bits() > holder.prefix.Bits()) {
+			holder = &registryBlocks[i]
+		}
+	}
+
+	if holder == nil || !holder.reserved {
+		return "", false
+	}
+
+	return holder.name + " (" + holder.prefix.String() + ")", true
+}
+
+// ASN returns why asn is reserved, and true, when it is. It returns "" and
+// false when asn is not reserved.
+func ASN(asn int) (string, bool) {
+	for _, r := range reservedASRanges {
+		if asn < r.first || asn > r.last {
+			continue
+		}
+
+		if r.first == r.last {
+			return r.name + " (AS" + strconv.Itoa(asn) + ")", true
+		}
+
+		return r.name + " (AS" + strconv.Itoa(r.first) + "-AS" +
+			strconv.Itoa(r.last) + ")", true
+	}
+
+	return "", false
+}
+
+// The names that the registries give to more than one row.
+const (
+	privateUse              = "Private-Use"
+	documentation           = "Documentation"
+	benchmarking            = "Benchmarking"
+	ietfProtocolAssignments = "IETF Protocol Assignments"
+	portControlAnycast      = "Port Control Protocol Anycast"
+	natTraversalAnycast     = "Traversal Using Relays around NAT Anycast"
+	nat64Discovery          = "NAT64/DNS64 Discovery"
+	amt                     = "AMT"
+	as112DirectDelegation   = "Direct Delegation AS112 Service"
+	ipv4IPv6Translation     = "IPv4-IPv6 Translat."
+	multicast               = "Multicast"
+)
+
+// block is one row of an IANA address registry.
+type block struct {
+	prefix netip.Prefix
+	name   string
+	// reserved says that no network should announce the row's addresses on
+	// the internet.
+	reserved bool
+}
+
+// reservedBlock returns a reserved row: a multicast block, or a special-purpose
+// row whose Globally Reachable column is False.
+func reservedBlock(prefix, name string) block {
+	return block{prefix: netip.MustParsePrefix(prefix), name: name, reserved: true}
+}
+
+// reachableBlock returns a special-purpose row whose Globally Reachable column
+// is True or N/A. Such a row matters only inside a reserved block, whose
+// addresses it lets be announced.
+func reachableBlock(prefix, name string) block {
+	return block{prefix: netip.MustParsePrefix(prefix), name: name}
+}
+
+// registryBlocks are the rows of the IANA special-purpose address registries,
+// without the deprecated ones:
+//   - https://www.iana.org/assignments/iana-ipv4-special-registry/
+//   - https://www.iana.org/assignments/iana-ipv6-special-registry/
+//
+// They also hold the multicast blocks, which the IANA address space registries
+// list as Multicast:
+//   - https://www.iana.org/assignments/ipv4-address-space/
+//   - https://www.iana.org/assignments/ipv6-address-space/
+//
+//nolint:gochecknoglobals // a fixed list, parsed once
+var registryBlocks = []block{
+	reservedBlock("0.0.0.0/8", "This network"),
+	reservedBlock("0.0.0.0/32", "This host on this network"),
+	reservedBlock("10.0.0.0/8", privateUse),
+	reservedBlock("100.64.0.0/10", "Shared Address Space"),
+	reservedBlock("127.0.0.0/8", "Loopback"),
+	reservedBlock("169.254.0.0/16", "Link Local"),
+	reservedBlock("172.16.0.0/12", privateUse),
+	reservedBlock("192.0.0.0/24", ietfProtocolAssignments),
+	reservedBlock("192.0.0.0/29", "IPv4 Service Continuity Prefix"),
+	reservedBlock("192.0.0.8/32", "IPv4 dummy address"),
+	reachableBlock("192.0.0.9/32", portControlAnycast),
+	reachableBlock("192.0.0.10/32", natTraversalAnycast),
+	reservedBlock("192.0.0.170/32", nat64Discovery),
+	reservedBlock("192.0.0.171/32", nat64Discovery),
+	reservedBlock("192.0.2.0/24", "Documentation (TEST-NET-1)"),
+	reachableBlock("192.31.196.0/24", "AS112-v4"),
+	reachableBlock("192.52.193.0/24", amt),
+	reservedBlock("192.88.99.2/32", "6a44-relay anycast address"),
+	reservedBlock("192.168.0.0/16", privateUse),
+	reachableBlock("192.175.48.0/24", as112DirectDelegation),
+	reservedBlock("198.18.0.0/15", benchmarking),
+	reservedBlock("198.51.100.0/24", "Documentation (TEST-NET-2)"),
+	reservedBlock("203.0.113.0/24", "Documentation (TEST-NET-3)"),
+	reservedBlock("224.0.0.0/4", multicast),
+	reservedBlock("240.0.0.0/4", "Reserved"),
+	reservedBlock("255.255.255.255/32", "Limited Broadcast"),
+
+	reservedBlock("::1/128", "Loopback Address"),
+	reservedBlock("::/128", "Unspecified Address"),
+	reservedBlock("::ffff:0:0/96", "IPv4-mapped Address"),
+	reachableBlock("64:ff9b::/96", ipv4IPv6Translation),
+	reservedBlock("64:ff9b:1::/48", ipv4IPv6Translation),
+	reservedBlock("100::/64", "Discard-Only Address Block"),
+	reservedBlock("100:0:0:1::/64", "Dummy IPv6 Prefix"),
+	reservedBlock("2001::/23", ietfProtocolAssignments),
+	reachableBlock("2001::/32", "TEREDO"),
+	reachableBlock("2001:1::1/128", portControlAnycast),
+	reachableBlock("2001:1::2/128", natTraversalAnycast),
+	reachableBlock("2001:1::3/128", "DNS-SD Service Registration Protocol Anycast"),
+	reservedBlock("2001:2::/48", benchmarking),
+	reachableBlock("2001:3::/32", amt),
+	reachableBlock("2001:4:112::/48", "AS112-v6"),
+	reachableBlock("2001:20::/28", "ORCHIDv2"),
+	reachableBlock("2001:30::/28", "Drone Remote ID Protocol Entity Tags (DETs) Prefix"),
+	reservedBlock("2001:db8::/32", documentation),
+	reachableBlock("2002::/16", "6to4"),
+	reachableBlock("2620:4f:8000::/48", as112DirectDelegation),
+	reservedBlock("3fff::/20", documentation),
+	reservedBlock("5f00::/16", "Segment Routing (SRv6) SIDs"),
+	reservedBlock("fc00::/7", "Unique-Local"),
+	reservedBlock("fe80::/10", "Link-Local Unicast"),
+	reservedBlock("ff00::/8", multicast),
+}
+
+// asRange is a range of reserved AS numbers, first to last.
+type asRange struct {
+	first, last int
+	name        string
+}
+
+// The reserved AS numbers of the IANA special-purpose AS numbers registry.
+const (
+	asTrans                = 23456
+	firstDocumentationAS16 = 64496
+	lastDocumentationAS16  = 64511
+	firstPrivateUseAS16    = 64512
+	lastPrivateUseAS16     = 65534
+	lastAS16               = 65535
+	firstDocumentationAS32 = 65536
+	lastDocumentationAS32  = 65551
+	firstPrivateUseAS32    = 4200000000
+	lastPrivateUseAS32     = 4294967294
+	lastAS32               = 4294967295
+)
+
+// reservedASRanges are the reserved rows of the IANA special-purpose AS numbers
+// registry, https://www.iana.org/assignments/iana-as-numbers-special-registry/.
+// AS 0 is left out: RouteWatch uses it for a route with no known origin. AS 112
+// is left out because the AS112 project announces routes with it.
+//
+//nolint:gochecknoglobals // a fixed list
+var reservedASRanges = []asRange{
+	{first: asTrans, last: asTrans, name: "AS_TRANS"},
+	{first: firstDocumentationAS16, last: lastDocumentationAS16, name: documentation},
+	{first: firstPrivateUseAS16, last: lastPrivateUseAS16, name: privateUse},
+	{first: lastAS16, last: lastAS16, name: "Last 16-bit AS number"},
+	{first: firstDocumentationAS32, last: lastDocumentationAS32, name: documentation},
+	{first: firstPrivateUseAS32, last: lastPrivateUseAS32, name: privateUse},
+	{first: lastAS32, last: lastAS32, name: "Last 32-bit AS number"},
+}

internal/bogon/bogon_test.go

@@ -0,0 +1,95 @@
+package bogon_test
+
+import (
+	"net/netip"
+	"strconv"
+	"testing"
+
+	"git.eeqj.de/sneak/routewatch/internal/bogon"
+)
+
+func TestPrefix(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		prefix string
+		// want is why the prefix is reserved, or "" when it is not.
+		want string
+	}{
+		{"10.1.2.0/24", "Private-Use (10.0.0.0/8)"},
+		{"10.0.0.0/8", "Private-Use (10.0.0.0/8)"},
+		{"192.0.2.0/24", "Documentation (TEST-NET-1) (192.0.2.0/24)"},
+		{"2001:db8:1::/48", "Documentation (2001:db8::/32)"},
+		{"fd00::/8", "Unique-Local (fc00::/7)"},
+		// Multicast space, from the IANA address space registries.
+		{"224.0.0.0/4", "Multicast (224.0.0.0/4)"},
+		{"239.255.0.0/16", "Multicast (224.0.0.0/4)"},
+		{"ff00::/8", "Multicast (ff00::/8)"},
+		{"ff02::/16", "Multicast (ff00::/8)"},
+		// The most specific block names the reason.
+		{"0.0.0.0/32", "This host on this network (0.0.0.0/32)"},
+		{"2001:2::/48", "Benchmarking (2001:2::/48)"},
+		// Blocks that may be announced, inside reserved blocks.
+		{"192.0.0.9/32", ""},
+		{"2001:4:112::/48", ""},
+		// Blocks that may be announced, inside no reserved block.
+		{"192.175.48.0/24", ""},
+		{"2002::/16", ""},
+		// A prefix that holds a reserved block is not inside it.
+		{"192.0.0.0/16", ""},
+		{"0.0.0.0/0", ""},
+		// Prefixes anyone may announce.
+		{"8.8.8.0/24", ""},
+		{"2001:4860::/32", ""},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.prefix, func(t *testing.T) {
+			t.Parallel()
+
+			reason, reserved := bogon.Prefix(netip.MustParsePrefix(tc.prefix))
+			if reason != tc.want || reserved != (tc.want != "") {
+				t.Errorf("Prefix(%s) = %q, %v; want %q", tc.prefix, reason,
+					reserved, tc.want)
+			}
+		})
+	}
+}
+
+func TestASN(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		asn int
+		// want is why the AS number is reserved, or "" when it is not.
+		want string
+	}{
+		{23456, "AS_TRANS (AS23456)"},
+		{64496, "Documentation (AS64496-AS64511)"},
+		{64512, "Private-Use (AS64512-AS65534)"},
+		{65534, "Private-Use (AS64512-AS65534)"},
+		{65535, "Last 16-bit AS number (AS65535)"},
+		{65551, "Documentation (AS65536-AS65551)"},
+		{4200000000, "Private-Use (AS4200000000-AS4294967294)"},
+		{4294967295, "Last 32-bit AS number (AS4294967295)"},
+		// AS 0 means no known origin, and the AS112 project uses AS 112.
+		{0, ""},
+		{112, ""},
+		// Not handed out yet, which is not counted.
+		{65552, ""},
+		{15169, ""},
+		{64495, ""},
+	}
+
+	for _, tc := range tests {
+		t.Run(strconv.Itoa(tc.asn), func(t *testing.T) {
+			t.Parallel()
+
+			reason, reserved := bogon.ASN(tc.asn)
+			if reason != tc.want || reserved != (tc.want != "") {
+				t.Errorf("ASN(%d) = %q, %v; want %q", tc.asn, reason, reserved,
+					tc.want)
+			}
+		})
+	}
+}

internal/config/config.go

@@ -30,6 +30,14 @@ const (
 	maxPort = 65535
 )
 
+// The private address ranges of RFC 1918. The HTTP server trusts a reverse
+// proxy in any of them when TRUSTED_PROXIES is not set.
+const (
+	privateRange10  = "10.0.0.0/8"
+	privateRange172 = "172.16.0.0/12"
+	privateRange192 = "192.168.0.0/16"
+)
+
 var (
 	errRelativeXDGDataHome = errors.New("XDG_DATA_HOME must be an absolute path")
 	errUnsupportedOS       = errors.New("unsupported operating system")
@@ -159,11 +167,21 @@ func getPort() (int, error) {
 	return int(port), nil
 }
 
-// getTrustedProxies returns the addresses and CIDR ranges listed in
+// getTrustedProxies returns the reverse proxies the HTTP server trusts. When
-// TRUSTED_PROXIES, such as "10.0.0.0/8,192.0.2.1", or none when it is not set.
+// TRUSTED_PROXIES is not set, they are the private ranges of RFC 1918. When it
-// An address is returned as a range holding only that address.
+// is set, they are the addresses and CIDR ranges it lists, such as
+// "10.0.0.0/8,192.0.2.1", and none when it is empty. An address is returned as
+// a range holding only that address.
 func getTrustedProxies() ([]netip.Prefix, error) {
-	value := os.Getenv("TRUSTED_PROXIES")
+	value, set := os.LookupEnv("TRUSTED_PROXIES")
+	if !set {
+		return []netip.Prefix{
+			netip.MustParsePrefix(privateRange10),
+			netip.MustParsePrefix(privateRange172),
+			netip.MustParsePrefix(privateRange192),
+		}, nil
+	}
+
 	if value == "" {
 		return nil, nil
 	}

internal/config/config_internal_test.go

@@ -2,6 +2,7 @@ package config
 
 import (
 	"net/netip"
+	"os"
 	"runtime"
 	"slices"
 	"testing"
@@ -46,25 +47,47 @@ func TestNewRefusesInvalidPort(t *testing.T) {
 	}
 }
 
-func TestNewReadsTrustedProxies(t *testing.T) {
+// TestNewTrustsPrivateRangesByDefault checks that with TRUSTED_PROXIES unset
+// the trusted proxies are the private ranges of RFC 1918. Before the fix no
+// proxy was trusted, so a reverse proxy at a private address was taken for the
+// client (https://git.eeqj.de/sneak/routewatch/issues/198).
+func TestNewTrustsPrivateRangesByDefault(t *testing.T) {
 	t.Setenv("PORT", "")
 	t.Setenv("XDG_DATA_HOME", "")
 
+	// t.Setenv puts the variable back when the test ends.
 	t.Setenv("TRUSTED_PROXIES", "")
 
+	err := os.Unsetenv("TRUSTED_PROXIES")
+	if err != nil {
+		t.Fatal(err)
+	}
+
 	cfg, err := New()
 	if err != nil {
 		t.Fatalf("New() without TRUSTED_PROXIES: %v", err)
 	}
 
-	if len(cfg.TrustedProxies) != 0 {
+	want := []netip.Prefix{
-		t.Errorf("New() without TRUSTED_PROXIES: TrustedProxies = %v, want none",
+		netip.MustParsePrefix("10.0.0.0/8"),
-			cfg.TrustedProxies)
+		netip.MustParsePrefix("172.16.0.0/12"),
+		netip.MustParsePrefix("192.168.0.0/16"),
 	}
+	if !slices.Equal(cfg.TrustedProxies, want) {
+		t.Errorf("New() without TRUSTED_PROXIES: TrustedProxies = %v, want %v",
+			cfg.TrustedProxies, want)
+	}
+}
+
+// TestNewReadsTrustedProxies checks that a list in TRUSTED_PROXIES replaces
+// the default, and that TRUSTED_PROXIES set but empty trusts no proxy.
+func TestNewReadsTrustedProxies(t *testing.T) {
+	t.Setenv("PORT", "")
+	t.Setenv("XDG_DATA_HOME", "")
 
 	t.Setenv("TRUSTED_PROXIES", "10.0.0.0/8, 192.0.2.1,2001:db8::/32")
 
-	cfg, err = New()
+	cfg, err := New()
 	if err != nil {
 		t.Fatalf("New() with TRUSTED_PROXIES: %v", err)
 	}
@@ -77,6 +100,18 @@ func TestNewReadsTrustedProxies(t *testing.T) {
 	if !slices.Equal(cfg.TrustedProxies, want) {
 		t.Errorf("TrustedProxies = %v, want %v", cfg.TrustedProxies, want)
 	}
+
+	t.Setenv("TRUSTED_PROXIES", "")
+
+	cfg, err = New()
+	if err != nil {
+		t.Fatalf("New() with TRUSTED_PROXIES set but empty: %v", err)
+	}
+
+	if len(cfg.TrustedProxies) != 0 {
+		t.Errorf("New() with TRUSTED_PROXIES set but empty: TrustedProxies = %v, "+
+			"want none", cfg.TrustedProxies)
+	}
 }
 
 func TestNewRefusesInvalidTrustedProxies(t *testing.T) {

internal/database/database.go

@@ -972,6 +972,34 @@ func (d *Database) GetAS(ctx context.Context, asn int) (*ASN, bool, error) {
 	return &asnInfo, true, nil
 }
 
+// The queries of GetLastSeenASes. The index on last_seen answers each without
+// reading the whole table.
+const (
+	newestLastSeenASQuery = `
+	SELECT asn, handle, description, first_seen, last_seen
+	FROM asns ORDER BY last_seen DESC LIMIT 1`
+	oldestLastSeenASQuery = `
+	SELECT asn, handle, description, first_seen, last_seen
+	FROM asns ORDER BY last_seen ASC LIMIT 1`
+)
+
+// GetLastSeenASes returns two ASes of the asns table, with their handles,
+// descriptions and seen times: the one last seen most recently, and the one
+// last seen longest ago. Both are nil when the table holds no AS.
+func (d *Database) GetLastSeenASes(ctx context.Context) (*ASN, *ASN, error) {
+	newest, found, err := d.readOneAS(ctx, newestLastSeenASQuery)
+	if err != nil || !found {
+		return nil, nil, err
+	}
+
+	oldest, _, err := d.readOneAS(ctx, oldestLastSeenASQuery)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return newest, oldest, nil
+}
+
 // asWHOISQuery reads the handle, description and WHOIS details of one AS, and
 // when the WHOIS details were fetched.
 const asWHOISQuery = `
@@ -1379,6 +1407,29 @@ func (d *Database) Ping(ctx context.Context) error {
 	return nil
 }
 
+// readOneAS returns the AS that query reads, and whether it read one.
+func (d *Database) readOneAS(ctx context.Context, query string) (*ASN, bool, error) {
+	var (
+		asnInfo             ASN
+		handle, description sql.NullString
+	)
+
+	err := d.db.QueryRowContext(ctx, query).Scan(&asnInfo.ASN, &handle,
+		&description, &asnInfo.FirstSeen, &asnInfo.LastSeen)
+	if errors.Is(err, sql.ErrNoRows) {
+		return nil, false, nil
+	}
+
+	if err != nil {
+		return nil, false, fmt.Errorf("failed to query AS by last seen: %w", err)
+	}
+
+	asnInfo.Handle = handle.String
+	asnInfo.Description = description.String
+
+	return &asnInfo, true, nil
+}
+
 // truncateWAL runs the TRUNCATE checkpoint of Checkpoint on a WAL file of
 // walBytes, with the writing connection's busy timeout lowered to
 // truncateBusyTimeoutMs for it, and logs how long it took. The caller holds the

internal/database/database_internal_test.go

@@ -1003,6 +1003,62 @@ func TestGetASReadsTheRecordOrTheBuiltInList(t *testing.T) {
 	}
 }
 
+// TestGetLastSeenASes stores three ASes, each last seen at another time, and
+// expects the one last seen most recently and the one last seen longest ago.
+// An empty asns table gives neither.
+func TestGetLastSeenASes(t *testing.T) {
+	t.Parallel()
+
+	db, err := New(&config.Config{StateDir: t.TempDir()}, logger.New())
+	if err != nil {
+		t.Fatalf("failed to create database: %v", err)
+	}
+	defer func() { _ = db.Close() }()
+
+	newest, oldest, err := db.GetLastSeenASes(t.Context())
+	if err != nil || newest != nil || oldest != nil {
+		t.Fatalf("GetLastSeenASes() on an empty table = %+v, %+v, %v; want "+
+			"neither", newest, oldest, err)
+	}
+
+	const (
+		newestASN = 13335
+		middleASN = 15169
+		oldestASN = 3
+	)
+
+	start := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+
+	err = db.GetOrCreateASNBatch(map[int]SeenTimes{
+		middleASN: {First: start, Last: start.Add(time.Hour)},
+		newestASN: {First: start, Last: start.Add(2 * time.Hour)},
+		oldestASN: {First: start, Last: start.Add(time.Minute)},
+	})
+	if err != nil {
+		t.Fatalf("GetOrCreateASNBatch: %v", err)
+	}
+
+	newest, oldest, err = db.GetLastSeenASes(t.Context())
+	if err != nil {
+		t.Fatalf("GetLastSeenASes: %v", err)
+	}
+
+	listed, _ := asinfo.Get(newestASN)
+
+	if newest == nil || newest.ASN != newestASN ||
+		!newest.LastSeen.Equal(start.Add(2*time.Hour)) ||
+		newest.Description != listed.Description {
+		t.Errorf("newest = %+v, want AS%d (%s) last seen %v", newest, newestASN,
+			listed.Description, start.Add(2*time.Hour))
+	}
+
+	if oldest == nil || oldest.ASN != oldestASN ||
+		!oldest.LastSeen.Equal(start.Add(time.Minute)) {
+		t.Errorf("oldest = %+v, want AS%d last seen %v", oldest, oldestASN,
+			start.Add(time.Minute))
+	}
+}
+
 // TestGetASWHOISReadsTheStoredDetails stores an AS with WHOIS details and asks
 // GetASWHOIS for it and for an AS the asns table does not hold. The first gets
 // its stored handle, description and details, and the time they were fetched.

internal/database/interface.go

@@ -62,6 +62,7 @@ type Store interface {
 
 	// AS and prefix detail operations
 	GetAS(ctx context.Context, asn int) (*ASN, bool, error)
+	GetLastSeenASes(ctx context.Context) (*ASN, *ASN, error)
 	GetASWHOIS(ctx context.Context, asn int) (*ASN, error)
 	GetPrefixFirstSeen(ctx context.Context, prefix netip.Prefix) (time.Time, error)
 	GetASPeers(asn int) ([]ASPeer, error)

internal/database/schema.sql

@@ -83,6 +83,9 @@ CREATE INDEX IF NOT EXISTS idx_peerings_lookup ON peerings(as_a, as_b);
 -- Indexes for asns table
 CREATE INDEX IF NOT EXISTS idx_asns_asn ON asns(asn);
 CREATE INDEX IF NOT EXISTS idx_asns_whois_updated_at ON asns(whois_updated_at);
+-- Finds the AS last seen most recently and the one last seen longest ago, for
+-- the home page.
+CREATE INDEX IF NOT EXISTS idx_asns_last_seen ON asns(last_seen);
 
 -- Indexes for bgp_peers table
 CREATE INDEX IF NOT EXISTS idx_bgp_peers_asn ON bgp_peers(peer_asn);

internal/routetable/overview.go

@@ -0,0 +1,259 @@
+package routetable
+
+import (
+	"cmp"
+	"net/netip"
+	"slices"
+	"time"
+
+	"git.eeqj.de/sneak/routewatch/internal/bogon"
+	"git.eeqj.de/sneak/routewatch/internal/ristypes"
+)
+
+// walkBatch is how many prefixes the walk over the whole table reads in one
+// hold of the read lock. The updates waiting for the lock get it in between.
+const walkBatch = 10000
+
+// Overview holds figures about the whole table. Working them out takes a walk
+// over every prefix, so a caller asks for them now and then and keeps them.
+type Overview struct {
+	// NewestRoute and OldestRoute are the newest and the oldest kept routes,
+	// or nil when the table keeps none. Of several with the same time, it is
+	// any one of them.
+	NewestRoute *PrefixRoute
+	OldestRoute *PrefixRoute
+
+	// MostPrefixesASN is the AS that originates the most prefixes, and
+	// MostPrefixes is how many it originates. Of several with as many, it is
+	// the lowest AS number. AS 0, no known origin, counts neither here nor
+	// in the single-prefix figures.
+	MostPrefixesASN int
+	MostPrefixes    int
+
+	// SinglePrefixASes counts the ASes that originate one prefix.
+	SinglePrefixASes int
+	// NewestSinglePrefix is the newest kept route of those ASes, or nil when
+	// they keep none.
+	NewestSinglePrefix *PrefixRoute
+
+	// Bogons are the bogon announcements, in prefix order: at most the
+	// number Overview is asked for. BogonCount counts them all.
+	Bogons     []Bogon
+	BogonCount int
+
+	// MultipleOrigins are the prefixes that peers carry with more than one
+	// origin AS, in prefix order: at most the number Overview is asked for.
+	// MultipleOriginCount counts them all.
+	MultipleOrigins     []MultipleOriginPrefix
+	MultipleOriginCount int
+}
+
+// PrefixRoute is the time of a kept route, with its prefix and origin AS.
+type PrefixRoute struct {
+	Prefix    netip.Prefix
+	OriginASN int
+	Time      time.Time
+}
+
+// Bogon is a bogon announcement: a prefix and origin AS pair whose prefix or
+// origin AS is reserved, as package bogon tells.
+type Bogon struct {
+	Prefix    netip.Prefix
+	OriginASN int
+	// Peers is how many peers carry the prefix with this origin AS.
+	Peers int
+	// Reasons say why the prefix, the origin AS or both are reserved.
+	Reasons []string
+}
+
+// MultipleOriginPrefix is a prefix that peers carry with more than one origin
+// AS.
+type MultipleOriginPrefix struct {
+	Prefix netip.Prefix
+	// Origins are its origin ASes, in AS number order.
+	Origins []OriginPeers
+}
+
+// OriginPeers is one origin AS of a prefix, and how many peers carry the prefix
+// with it.
+type OriginPeers struct {
+	ASN   int
+	Peers int
+}
+
+// Overview works out the table's overview. It lists at most maxListed bogon
+// announcements and at most maxListed prefixes with more than one origin AS:
+// the first in prefix order. It walks over every prefix, but holds the read
+// lock for walkBatch prefixes at a time.
+func (t *Table) Overview(maxListed int) Overview {
+	var overview Overview
+
+	t.walkPrefixes(func(prefix netip.Prefix, origins []*origin) {
+		overview.noteKeptRoutes(prefix, origins)
+		overview.noteBogons(prefix, origins)
+		overview.noteMultipleOrigins(prefix, origins)
+	})
+
+	t.countPrefixesPerOrigin(&overview)
+
+	slices.SortFunc(overview.Bogons, func(a, b Bogon) int {
+		return cmp.Or(a.Prefix.Compare(b.Prefix),
+			cmp.Compare(a.OriginASN, b.OriginASN))
+	})
+	overview.BogonCount = len(overview.Bogons)
+	overview.Bogons = overview.Bogons[:min(maxListed, overview.BogonCount)]
+
+	slices.SortFunc(overview.MultipleOrigins, func(a, b MultipleOriginPrefix) int {
+		return a.Prefix.Compare(b.Prefix)
+	})
+	overview.MultipleOriginCount = len(overview.MultipleOrigins)
+	overview.MultipleOrigins =
+		overview.MultipleOrigins[:min(maxListed, overview.MultipleOriginCount)]
+
+	return overview
+}
+
+// walkPrefixes calls visit with every prefix of the table and its origins. It
+// holds the read lock, but lets it go after every walkBatch prefixes, so the
+// updates waiting for it get in. A prefix that is added or removed in such a
+// gap may or may not be visited, as Go allows for a map that changes during a
+// range over it. visit must not keep origins once it returns.
+func (t *Table) walkPrefixes(visit func(prefix netip.Prefix, origins []*origin)) {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+
+	visited := 0
+
+	for _, f := range []*family{&t.ipv4, &t.ipv6} {
+		for _, prefixes := range f.byLength {
+			for prefix, origins := range prefixes {
+				visit(prefix, origins)
+
+				visited++
+				if visited%walkBatch == 0 {
+					t.mu.RUnlock()
+					t.mu.RLock()
+				}
+			}
+		}
+	}
+}
+
+// countPrefixesPerOrigin works out the overview's figures of how many prefixes
+// each AS originates. It holds the read lock once, for one look at each origin
+// AS, of which there are far fewer than prefixes.
+func (t *Table) countPrefixesPerOrigin(overview *Overview) {
+	t.mu.RLock()
+	defer t.mu.RUnlock()
+
+	for asn, prefixes := range t.byOrigin {
+		if asn == ristypes.NoOrigin {
+			continue
+		}
+
+		count := len(prefixes)
+		if count > overview.MostPrefixes ||
+			(count == overview.MostPrefixes && asn < overview.MostPrefixesASN) {
+			overview.MostPrefixesASN = asn
+			overview.MostPrefixes = count
+		}
+
+		if count == 1 {
+			overview.SinglePrefixASes++
+			overview.noteSinglePrefix(asn, prefixes)
+		}
+	}
+}
+
+// noteSinglePrefix makes the newest kept route of asn, whose one prefix is in
+// prefixes, the overview's newest single-prefix route when it is newer.
+func (overview *Overview) noteSinglePrefix(
+	asn int, prefixes map[netip.Prefix]*origin,
+) {
+	for prefix, o := range prefixes {
+		newest := o.newestTime()
+		if newest == nil {
+			continue
+		}
+
+		if overview.NewestSinglePrefix == nil ||
+			newest.After(overview.NewestSinglePrefix.Time) {
+			overview.NewestSinglePrefix = &PrefixRoute{
+				Prefix: prefix, OriginASN: asn, Time: *newest,
+			}
+		}
+	}
+}
+
+// noteKeptRoutes makes the newest and the oldest kept routes of prefix's
+// origins the overview's newest and oldest routes when they are newer or older.
+func (overview *Overview) noteKeptRoutes(prefix netip.Prefix, origins []*origin) {
+	for _, o := range origins {
+		if len(o.routes) == 0 {
+			continue
+		}
+
+		newest := o.routes[0].time
+		if overview.NewestRoute == nil || newest.After(overview.NewestRoute.Time) {
+			overview.NewestRoute = &PrefixRoute{
+				Prefix: prefix, OriginASN: o.asn, Time: newest,
+			}
+		}
+
+		oldest := o.routes[len(o.routes)-1].time
+		if overview.OldestRoute == nil || oldest.Before(overview.OldestRoute.Time) {
+			overview.OldestRoute = &PrefixRoute{
+				Prefix: prefix, OriginASN: o.asn, Time: oldest,
+			}
+		}
+	}
+}
+
+// noteBogons adds each origin of prefix to the overview's bogon announcements
+// when the prefix or the origin AS is reserved.
+func (overview *Overview) noteBogons(prefix netip.Prefix, origins []*origin) {
+	prefixReason, prefixReserved := bogon.Prefix(prefix)
+
+	for _, o := range origins {
+		asnReason, asnReserved := bogon.ASN(o.asn)
+		if !prefixReserved && !asnReserved {
+			continue
+		}
+
+		announcement := Bogon{
+			Prefix: prefix, OriginASN: o.asn, Peers: int(o.peers.Count()),
+		}
+
+		if prefixReserved {
+			announcement.Reasons = append(announcement.Reasons, prefixReason)
+		}
+
+		if asnReserved {
+			announcement.Reasons = append(announcement.Reasons, asnReason)
+		}
+
+		overview.Bogons = append(overview.Bogons, announcement)
+	}
+}
+
+// noteMultipleOrigins adds prefix to the overview's prefixes with more than one
+// origin AS when it has more than one.
+func (overview *Overview) noteMultipleOrigins(
+	prefix netip.Prefix, origins []*origin,
+) {
+	if len(origins) <= 1 {
+		return
+	}
+
+	entry := MultipleOriginPrefix{
+		Prefix:  prefix,
+		Origins: make([]OriginPeers, 0, len(origins)),
+	}
+
+	for _, o := range origins {
+		entry.Origins = append(entry.Origins,
+			OriginPeers{ASN: o.asn, Peers: int(o.peers.Count())})
+	}
+
+	overview.MultipleOrigins = append(overview.MultipleOrigins, entry)
+}

internal/routetable/overview_internal_test.go

@@ -0,0 +1,133 @@
+package routetable
+
+import (
+	"net/netip"
+	"runtime"
+	"testing"
+	"time"
+)
+
+// TestWalkPrefixesVisitsEveryPrefix walks a table with more prefixes than two
+// of the walk's batches, while another goroutine keeps adding and removing
+// other prefixes of the same mask length. The walk lets the lock go between
+// batches, so those updates get in while it runs. Every prefix that was in
+// the table all along must be visited once.
+func TestWalkPrefixesVisitsEveryPrefix(t *testing.T) {
+	t.Parallel()
+
+	const (
+		asn  = 1000
+		peer = "192.0.2.1"
+		// prefixCount is more prefixes than two of the walk's batches.
+		prefixCount = 2*walkBatch + 1
+	)
+
+	routeTime := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	table := New(Params{})
+	prefixes := make([]netip.Prefix, 0, prefixCount)
+	addr := netip.MustParseAddr("1.0.0.0")
+
+	for range prefixCount {
+		prefix := netip.PrefixFrom(addr, addr.BitLen())
+		table.Announce(prefix, asn, Route{Peer: peer, Time: routeTime})
+		prefixes = append(prefixes, prefix)
+		addr = addr.Next()
+	}
+
+	stop := make(chan struct{})
+	updated := make(chan struct{})
+
+	go func() {
+		defer close(updated)
+
+		other := netip.MustParseAddr("2.0.0.0")
+
+		for {
+			select {
+			case <-stop:
+				return
+			default:
+			}
+
+			prefix := netip.PrefixFrom(other, other.BitLen())
+			table.Announce(prefix, asn, Route{Peer: peer, Time: routeTime})
+			table.Withdraw(prefix, peer)
+
+			other = other.Next()
+		}
+	}()
+
+	visits := make(map[netip.Prefix]int)
+
+	table.walkPrefixes(func(prefix netip.Prefix, _ []*origin) {
+		visits[prefix]++
+	})
+
+	close(stop)
+	<-updated
+
+	for _, prefix := range prefixes {
+		if visits[prefix] != 1 {
+			t.Fatalf("the walk visited %s %d times, want once", prefix,
+				visits[prefix])
+		}
+	}
+}
+
+// TestWalkPrefixesLetsUpdatesIn starts an update during the walk's first
+// batch. The update must have been made by the time the walk visits the first
+// prefix of its second batch, because the walk lets the lock go in between.
+func TestWalkPrefixesLetsUpdatesIn(t *testing.T) {
+	t.Parallel()
+
+	const (
+		asn  = 1000
+		peer = "192.0.2.1"
+	)
+
+	routeTime := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	table := New(Params{})
+	addr := netip.MustParseAddr("1.0.0.0")
+
+	for range walkBatch + 1 {
+		prefix := netip.PrefixFrom(addr, addr.BitLen())
+		table.Announce(prefix, asn, Route{Peer: peer, Time: routeTime})
+
+		addr = addr.Next()
+	}
+
+	updatePrefix := netip.MustParsePrefix("2.0.0.0/8")
+	updateDone := make(chan struct{})
+	visited := 0
+	madeBeforeSecondBatch := false
+
+	table.walkPrefixes(func(netip.Prefix, []*origin) {
+		visited++
+
+		switch visited {
+		case 1:
+			go func() {
+				defer close(updateDone)
+
+				table.Announce(updatePrefix, asn, Route{Peer: peer, Time: routeTime})
+			}()
+
+			// Wait until the update waits for the lock. TryRLock fails
+			// once a writer waits.
+			for table.mu.TryRLock() {
+				table.mu.RUnlock()
+				runtime.Gosched()
+			}
+		case walkBatch + 1:
+			// The walk holds the read lock, so the table can be read.
+			madeBeforeSecondBatch = table.origins(updatePrefix) != nil
+		}
+	})
+
+	<-updateDone
+
+	if !madeBeforeSecondBatch {
+		t.Fatal("an update started during the walk's first batch was not made " +
+			"before its second batch")
+	}
+}

internal/routetable/overview_test.go

@@ -0,0 +1,231 @@
+package routetable_test
+
+import (
+	"net/netip"
+	"reflect"
+	"testing"
+
+	"git.eeqj.de/sneak/routewatch/internal/routetable"
+)
+
+// Origin ASes that are not reserved, unlike asA, asB and asC, which are
+// documentation AS numbers and so make bogon announcements.
+const (
+	asOne   = 1000
+	asTwo   = 2000
+	asThree = 3000
+	asFour  = 4000
+	asFive  = 5000
+
+	// noKnownOrigin is the origin AS of a route whose path ends in an AS
+	// set.
+	noKnownOrigin = 0
+	// privateUseAS and asTrans are reserved AS numbers.
+	privateUseAS = 64512
+	asTrans      = 23456
+
+	// maxListed is how many bogon announcements and prefixes with more than
+	// one origin AS the tests ask Overview for.
+	maxListed = 10
+)
+
+// prefixRoute returns the PrefixRoute of prefix with origin AS asn, second
+// seconds after the start.
+func prefixRoute(prefix string, asn, second int) *routetable.PrefixRoute {
+	return &routetable.PrefixRoute{
+		Prefix: netip.MustParsePrefix(prefix), OriginASN: asn, Time: at(second),
+	}
+}
+
+func TestOverviewOfAnEmptyTable(t *testing.T) {
+	t.Parallel()
+
+	got := routetable.New(routetable.Params{}).Overview(maxListed)
+	if !reflect.DeepEqual(got, routetable.Overview{}) {
+		t.Errorf("Overview() = %+v, want no figures", got)
+	}
+}
+
+// TestOverviewNewestAndOldestRoutes checks that the newest and the oldest kept
+// routes are found among every origin's kept routes, and that withdrawn routes
+// no longer count.
+func TestOverviewNewestAndOldestRoutes(t *testing.T) {
+	t.Parallel()
+
+	table := routetable.New(routetable.Params{})
+	announceAll(table, "1.0.0.0/24", asOne, 20, peerA, peerB)
+	// The oldest is the older of this origin's two kept routes.
+	announceAll(table, "2.0.0.0/24", asTwo, 10, peerA, peerB)
+	announceAll(table, "2001:4860::/32", asThree, 40, peerC)
+	// Withdrawn routes, newer and older than every other.
+	announceAll(table, "3.0.0.0/24", asOne, 50, peerA)
+	announceAll(table, "4.0.0.0/24", asOne, 5, peerB)
+	table.Withdraw(netip.MustParsePrefix("3.0.0.0/24"), peerA)
+	table.Withdraw(netip.MustParsePrefix("4.0.0.0/24"), peerB)
+
+	got := table.Overview(maxListed)
+
+	want := prefixRoute("2001:4860::/32", asThree, 40)
+	if !reflect.DeepEqual(got.NewestRoute, want) {
+		t.Errorf("NewestRoute = %+v, want %+v", got.NewestRoute, want)
+	}
+
+	want = prefixRoute("2.0.0.0/24", asTwo, 10)
+	if !reflect.DeepEqual(got.OldestRoute, want) {
+		t.Errorf("OldestRoute = %+v, want %+v", got.OldestRoute, want)
+	}
+}
+
+// TestOverviewPrefixesPerOrigin checks the AS that originates the most
+// prefixes and the ASes that originate one.
+func TestOverviewPrefixesPerOrigin(t *testing.T) {
+	t.Parallel()
+
+	table := routetable.New(routetable.Params{})
+	// asOne and asTwo originate two prefixes each; the lower AS number counts.
+	announceAll(table, "1.0.0.0/24", asTwo, 10, peerA)
+	announceAll(table, "1.0.1.0/24", asTwo, 10, peerA)
+	announceAll(table, "2.0.0.0/24", asOne, 10, peerA)
+	announceAll(table, "2.0.1.0/24", asOne, 10, peerB)
+	// Three ASes originate one prefix. asThree's route is the newest, and
+	// asFive's origin keeps no route: peers B and C withdrew theirs.
+	announceAll(table, "3.0.0.0/24", asThree, 30, peerA)
+	announceAll(table, "4.0.0.0/24", asFour, 20, peerA)
+	announceAll(table, "5.0.0.0/24", asFive, 40, peerA, peerB, peerC)
+	table.Withdraw(netip.MustParsePrefix("5.0.0.0/24"), peerB)
+	table.Withdraw(netip.MustParsePrefix("5.0.0.0/24"), peerC)
+
+	got := table.Overview(maxListed)
+
+	if got.MostPrefixesASN != asOne || got.MostPrefixes != 2 {
+		t.Errorf("most prefixes: AS%d with %d, want AS%d with 2",
+			got.MostPrefixesASN, got.MostPrefixes, asOne)
+	}
+
+	if got.SinglePrefixASes != 3 {
+		t.Errorf("SinglePrefixASes = %d, want 3", got.SinglePrefixASes)
+	}
+
+	want := prefixRoute("3.0.0.0/24", asThree, 30)
+	if !reflect.DeepEqual(got.NewestSinglePrefix, want) {
+		t.Errorf("NewestSinglePrefix = %+v, want %+v", got.NewestSinglePrefix, want)
+	}
+}
+
+// TestOverviewLeavesOutNoKnownOrigin checks that AS 0, which stands for no
+// known origin, counts in neither the most nor the single-prefix figures. It
+// originates one prefix, with a route newer than asOne's, and asOne would lose
+// the tie for the most prefixes to it.
+func TestOverviewLeavesOutNoKnownOrigin(t *testing.T) {
+	t.Parallel()
+
+	table := routetable.New(routetable.Params{})
+	announceAll(table, "1.0.0.0/24", asOne, 10, peerA)
+	announceAll(table, "2.0.0.0/24", noKnownOrigin, 20, peerA)
+
+	got := table.Overview(maxListed)
+
+	if got.MostPrefixesASN != asOne || got.SinglePrefixASes != 1 {
+		t.Errorf("most prefixes AS%d, %d single-prefix ASes; want AS%d, 1",
+			got.MostPrefixesASN, got.SinglePrefixASes, asOne)
+	}
+
+	want := prefixRoute("1.0.0.0/24", asOne, 10)
+	if !reflect.DeepEqual(got.NewestSinglePrefix, want) {
+		t.Errorf("NewestSinglePrefix = %+v, want %+v", got.NewestSinglePrefix, want)
+	}
+}
+
+// TestOverviewBogons checks which routes are bogon announcements and why, in
+// prefix order, and that a smaller maxListed lists fewer but counts them all.
+func TestOverviewBogons(t *testing.T) {
+	t.Parallel()
+
+	table := routetable.New(routetable.Params{})
+	// A reserved prefix, carried by two peers.
+	announceAll(table, "192.168.0.0/16", asOne, 10, peerA, peerB)
+	// A reserved origin AS.
+	announceAll(table, "1.0.0.0/24", privateUseAS, 10, peerA)
+	// Both.
+	announceAll(table, "10.0.0.0/8", asTrans, 10, peerA)
+	// Neither: a normal route, and a block that may be announced although it
+	// lies inside a reserved one.
+	announceAll(table, "1.0.1.0/24", asOne, 10, peerA)
+	announceAll(table, "2001:4:112::/48", asTwo, 10, peerA)
+
+	want := []routetable.Bogon{
+		{
+			Prefix: netip.MustParsePrefix("1.0.0.0/24"), OriginASN: privateUseAS,
+			Peers: 1, Reasons: []string{"Private-Use (AS64512-AS65534)"},
+		},
+		{
+			Prefix: netip.MustParsePrefix("10.0.0.0/8"), OriginASN: asTrans,
+			Peers: 1,
+			Reasons: []string{
+				"Private-Use (10.0.0.0/8)", "AS_TRANS (AS23456)",
+			},
+		},
+		{
+			Prefix: netip.MustParsePrefix("192.168.0.0/16"), OriginASN: asOne,
+			Peers: 2, Reasons: []string{"Private-Use (192.168.0.0/16)"},
+		},
+	}
+
+	got := table.Overview(maxListed)
+	if !reflect.DeepEqual(got.Bogons, want) || got.BogonCount != len(want) {
+		t.Errorf("Overview(%d): %d bogons %+v, want %d %+v", maxListed,
+			got.BogonCount, got.Bogons, len(want), want)
+	}
+
+	const fewer = 2
+
+	got = table.Overview(fewer)
+	if !reflect.DeepEqual(got.Bogons, want[:fewer]) || got.BogonCount != len(want) {
+		t.Errorf("Overview(%d): %d bogons %+v, want %d %+v", fewer,
+			got.BogonCount, got.Bogons, len(want), want[:fewer])
+	}
+}
+
+// TestOverviewMultipleOrigins checks the prefixes with more than one origin
+// AS, in prefix order, and that a smaller maxListed lists fewer but counts them
+// all.
+func TestOverviewMultipleOrigins(t *testing.T) {
+	t.Parallel()
+
+	table := routetable.New(routetable.Params{})
+	announceAll(table, "2001:4860::/32", asThree, 10, peerA)
+	announceAll(table, "2001:4860::/32", asTwo, 10, peerB)
+	announceAll(table, "1.0.0.0/24", asOne, 10, peerA, peerB)
+	announceAll(table, "1.0.0.0/24", asTwo, 30, peerC)
+	// One origin only.
+	announceAll(table, "2.0.0.0/24", asOne, 10, peerA, peerB)
+
+	want := []routetable.MultipleOriginPrefix{
+		{
+			Prefix: netip.MustParsePrefix("1.0.0.0/24"),
+			Origins: []routetable.OriginPeers{
+				{ASN: asOne, Peers: 2}, {ASN: asTwo, Peers: 1},
+			},
+		},
+		{
+			Prefix: netip.MustParsePrefix("2001:4860::/32"),
+			Origins: []routetable.OriginPeers{
+				{ASN: asTwo, Peers: 1}, {ASN: asThree, Peers: 1},
+			},
+		},
+	}
+
+	got := table.Overview(maxListed)
+	if !reflect.DeepEqual(got.MultipleOrigins, want) ||
+		got.MultipleOriginCount != len(want) {
+		t.Errorf("Overview(%d): %d prefixes %+v, want %d %+v", maxListed,
+			got.MultipleOriginCount, got.MultipleOrigins, len(want), want)
+	}
+
+	got = table.Overview(1)
+	if !reflect.DeepEqual(got.MultipleOrigins, want[:1]) ||
+		got.MultipleOriginCount != len(want) {
+		t.Errorf("Overview(1): %d prefixes %+v, want %d %+v",
+			got.MultipleOriginCount, got.MultipleOrigins, len(want), want[:1])
+	}
+}

internal/routetable/reads.go

@@ -14,6 +14,9 @@ type PrefixSummary struct {
 	// OriginASN is the origin AS that the most peers carry the prefix with.
 	// When several have as many peers, it is the lowest AS number.
 	OriginASN int
+	// OriginASNs are all the origin ASes that peers carry the prefix with, in
+	// AS number order.
+	OriginASNs []int
 	// Peers is how many peers carry the prefix.
 	Peers int
 	// Newest is the time of the newest kept route of the prefix, or nil when
@@ -211,10 +214,12 @@ func (t *Table) addresses(peers *bitset.BitSet) []string {
 // summarize returns the summary of prefix, whose origins are in AS number
 // order.
 func summarize(prefix netip.Prefix, origins []*origin) PrefixSummary {
-	summary := PrefixSummary{Prefix: prefix}
+	summary := PrefixSummary{Prefix: prefix, OriginASNs: make([]int, 0, len(origins))}
 	mostPeers := 0
 
 	for _, o := range origins {
+		summary.OriginASNs = append(summary.OriginASNs, o.asn)
+
 		peers := int(o.peers.Count())
 		summary.Peers += peers
 

internal/routetable/reads_test.go

@@ -46,21 +46,22 @@ func TestLookup(t *testing.T) {
 	tests := []struct {
 		addr string
 		// want is the summary's prefix, or empty when none is found.
-		want      string
+		want       string
-		originASN int
+		originASN  int
-		peers     int
+		originASNs []int
-		newest    int // in seconds after the start; 0 for none
+		peers      int
+		newest     int // in seconds after the start; 0 for none
 	}{
-		{"10.1.2.3", prefixV4, asA, 2, 20},
+		{"10.1.2.3", prefixV4, asA, []int{asA, asB}, 2, 20},
-		{"::ffff:10.1.2.3", prefixV4, asA, 2, 20},
+		{"::ffff:10.1.2.3", prefixV4, asA, []int{asA, asB}, 2, 20},
-		{"10.1.3.4", "10.1.0.0/16", asB, 3, 30},
+		{"10.1.3.4", "10.1.0.0/16", asB, []int{asA, asB}, 3, 30},
-		{"10.2.0.1", "10.0.0.0/8", asA, 1, 10},
+		{"10.2.0.1", "10.0.0.0/8", asA, []int{asA}, 1, 10},
-		{"10.9.0.1", "10.9.0.0/16", asA, 1, 0},
+		{"10.9.0.1", "10.9.0.0/16", asA, []int{asA}, 1, 0},
-		{"192.0.2.1", "", 0, 0, 0},
+		{"192.0.2.1", "", 0, nil, 0, 0},
-		{"2001:db8:1::5", prefixV6, asB, 1, 20},
+		{"2001:db8:1::5", prefixV6, asB, []int{asB}, 1, 20},
-		{"2001:db8:2::1", "2001:db8::/32", asA, 1, 10},
+		{"2001:db8:2::1", "2001:db8::/32", asA, []int{asA}, 1, 10},
-		{"3000::1", "3000::/16", asA, 1, 10},
+		{"3000::1", "3000::/16", asA, []int{asA}, 1, 10},
-		{"2001:db9::1", "", 0, 0, 0},
+		{"2001:db9::1", "", 0, nil, 0, 0},
 	}
 
 	for _, tc := range tests {
@@ -77,9 +78,10 @@ func TestLookup(t *testing.T) {
 			}
 
 			want := routetable.PrefixSummary{
-				Prefix:    netip.MustParsePrefix(tc.want),
+				Prefix:     netip.MustParsePrefix(tc.want),
-				OriginASN: tc.originASN,
+				OriginASN:  tc.originASN,
-				Peers:     tc.peers,
+				OriginASNs: tc.originASNs,
+				Peers:      tc.peers,
 			}
 			if tc.newest != 0 {
 				want.Newest = timeAt(tc.newest)
@@ -166,7 +168,8 @@ func TestSamplePrefixes(t *testing.T) {
 
 			for _, got := range sample {
 				want := routetable.PrefixSummary{
-					Prefix: got.Prefix, OriginASN: asA, Peers: 1, Newest: timeAt(10),
+					Prefix: got.Prefix, OriginASN: asA, OriginASNs: []int{asA},
+					Peers: 1, Newest: timeAt(10),
 				}
 				if seen[got.Prefix] || got.Prefix.Bits() != tc.maskLength ||
 					!reflect.DeepEqual(got, want) {

internal/routetable/routetable_test.go

@@ -625,6 +625,7 @@ func TestConcurrentUse(t *testing.T) {
 		func(int) { table.OriginatedPrefixes(asA) },
 		func(int) { table.SamplePrefixes(ipVersion, prefix.Bits(), sampleSize) },
 		func(int) { table.Counts() },
+		func(int) { table.Overview(sampleSize) },
 	}
 
 	var wg sync.WaitGroup

internal/routewatch/app_integration_internal_test.go

@@ -223,6 +223,35 @@ func (m *mockStore) GetAS(_ context.Context, asn int) (*database.ASN, bool, erro
 	return &database.ASN{ASN: asn}, false, nil
 }
 
+// GetLastSeenASes returns copies of the stored ASes last seen most recently
+// and longest ago, or neither when none is stored.
+func (m *mockStore) GetLastSeenASes(
+	_ context.Context,
+) (*database.ASN, *database.ASN, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	var newest, oldest *database.ASN
+
+	for _, asn := range m.ASNs {
+		if newest == nil || asn.LastSeen.After(newest.LastSeen) {
+			newest = asn
+		}
+
+		if oldest == nil || asn.LastSeen.Before(oldest.LastSeen) {
+			oldest = asn
+		}
+	}
+
+	if newest == nil {
+		return nil, nil, nil
+	}
+
+	newestCopy, oldestCopy := *newest, *oldest
+
+	return &newestCopy, &oldestCopy, nil
+}
+
 // GetASWHOIS returns the stored AS, or only its number when none is stored.
 func (m *mockStore) GetASWHOIS(ctx context.Context, asn int) (*database.ASN, error) {
 	asnInfo, _, err := m.GetAS(ctx, asn)
@@ -605,12 +634,15 @@ func TestShutdownReturnsByItsDeadlineWhileAWriteIsBlocked(t *testing.T) {
 	cfg := &config.Config{Port: port}
 	s := streamer.New(log, metrics.New())
 
+	// A started server reads its routing table in the background, so it
+	// needs one.
 	rw := New(Dependencies{
 		DB:       store,
 		Streamer: s,
-		Server:   server.New(store, nil, s, log, cfg),
+		Server: server.New(store, routetable.New(routetable.Params{}), s, log,
-		Logger:   log,
+			cfg),
-		Config:   cfg,
+		Logger: log,
+		Config: cfg,
 	})
 
 	err := rw.server.Start(t.Context())

internal/server/handlers.go

@@ -23,7 +23,6 @@ import (
 	"git.eeqj.de/sneak/routewatch/internal/streamer"
 	"git.eeqj.de/sneak/routewatch/internal/templates"
 	asinfo "git.eeqj.de/sneak/routewatch/pkg/asinfo"
-	"github.com/dustin/go-humanize"
 	"github.com/go-chi/chi/v5"
 )
 
@@ -160,6 +159,7 @@ func (s *Server) handleIndex() http.HandlerFunc {
 		err := tmpl.Execute(w, indexPageData{
 			CSPNonce: cspNonce(r.Context()),
 			ClientIP: extractClientIP(r),
+			Cards:    s.cards.Load(),
 		})
 		if err != nil {
 			s.logger.Error("Failed to render index template", "error", err)
@@ -181,6 +181,9 @@ type indexPageData struct {
 	// ClientIP is the visitor's address, which the IP information API card
 	// looks up: the address /ip/ would look up for the same request.
 	ClientIP string
+	// Cards is the copy of the cards that show figures of the routing table,
+	// or nil before the server has first worked them out.
+	Cards *homeCards
 }
 
 // writeJSONError writes a standardized JSON error response with the given
@@ -222,18 +225,23 @@ type WHOISStatsInfo struct {
 	NeverFetched      int     `json:"never_fetched"`
 	SuccessesLastHour int     `json:"successes_last_hour"`
 	ErrorsLastHour    int     `json:"errors_last_hour"`
-	CurrentInterval   string  `json:"current_interval"`
 	ConsecutiveFails  int     `json:"consecutive_fails"`
 	FreshPercent      float64 `json:"fresh_percent"`
+
+	// CurrentIntervalSeconds is the wait between two fetches. It can have a
+	// fractional part, such as 22.5.
+	CurrentIntervalSeconds float64 `json:"current_interval_seconds"`
 }
 
 // Stats is the /status.json answer: uptime, message counts, database stats,
-// and the routing table's figures. OldestRoute and NewestRoute are the times
+// and the routing table's figures. UptimeSeconds is the time since the stream
-// of the oldest and the newest kept routes.
+// last connected, or 0 if it has never connected. MemoryUsageBytes is the Go
+// heap in use. OldestRoute and NewestRoute are the times of the oldest and the
+// newest kept routes.
 //
 //nolint:tagliatelle // field names are the existing JSON API
 type Stats struct {
-	Uptime                 string               `json:"uptime"`
+	UptimeSeconds          int64                `json:"uptime_seconds"`
 	TotalMessages          uint64               `json:"total_messages"`
 	TotalBytes             uint64               `json:"total_bytes"`
 	TotalWireBytes         uint64               `json:"total_wire_bytes"`
@@ -243,7 +251,7 @@ type Stats struct {
 	Connected              bool                 `json:"connected"`
 	GoVersion              string               `json:"go_version"`
 	Goroutines             int                  `json:"goroutines"`
-	MemoryUsage            string               `json:"memory_usage"`
+	MemoryUsageBytes       uint64               `json:"memory_usage_bytes"`
 	ASNs                   int                  `json:"asns"`
 	Prefixes               int                  `json:"prefixes"`
 	IPv4Prefixes           int                  `json:"ipv4_prefixes"`
@@ -358,7 +366,7 @@ func (s *Server) statusStats(
 	runtime.ReadMemStats(&memStats)
 
 	return Stats{
-		Uptime:                 streamUptime(streamMetrics.ConnectedSince),
+		UptimeSeconds:          uptimeSeconds(streamMetrics.ConnectedSince),
 		TotalMessages:          streamMetrics.TotalMessages,
 		TotalBytes:             streamMetrics.TotalBytes,
 		TotalWireBytes:         streamMetrics.TotalWireBytes,
@@ -368,7 +376,7 @@ func (s *Server) statusStats(
 		Connected:              streamMetrics.Connected,
 		GoVersion:              runtime.Version(),
 		Goroutines:             runtime.NumGoroutine(),
-		MemoryUsage:            humanize.Bytes(memStats.Alloc),
+		MemoryUsageBytes:       memStats.Alloc,
 		ASNs:                   dbStats.ASNs,
 		Prefixes:               counts.IPv4Prefixes + counts.IPv6Prefixes,
 		IPv4Prefixes:           counts.IPv4Prefixes,
@@ -435,30 +443,31 @@ func (s *Server) getWHOISStats(ctx context.Context) *WHOISStatsInfo {
 		NeverFetched:      dbStats.NeverFetched,
 		SuccessesLastHour: fetcherStats.SuccessesLastHour,
 		ErrorsLastHour:    fetcherStats.ErrorsLastHour,
-		CurrentInterval:   fetcherStats.CurrentInterval.String(),
 		ConsecutiveFails:  fetcherStats.ConsecutiveFails,
 		FreshPercent:      freshPercent,
+
+		CurrentIntervalSeconds: fetcherStats.CurrentInterval.Seconds(),
 	}
 }
 
-// streamUptime is how long the stream has been connected, to the second, or
+// uptimeSeconds is the number of whole seconds since the stream last
-// "0s" if it has never connected.
+// connected, or 0 if it has never connected.
-func streamUptime(connectedSince time.Time) string {
+func uptimeSeconds(connectedSince time.Time) int64 {
 	if connectedSince.IsZero() {
-		return "0s"
+		return 0
 	}
 
-	return time.Since(connectedSince).Truncate(time.Second).String()
+	return int64(time.Since(connectedSince) / time.Second)
 }
 
-// connectionDuration is how long the stream has been connected, to the
+// connectionDurationSeconds is the number of whole seconds the stream has
-// second, or "disconnected".
+// been connected, or nil while it is not connected.
-func connectionDuration(connected bool, connectedSince time.Time) string {
+func connectionDurationSeconds(connected bool, connectedSince time.Time) *int64 {
 	if !connected || connectedSince.IsZero() {
-		return "disconnected"
+		return nil
 	}
 
-	return time.Since(connectedSince).Truncate(time.Second).String()
+	return new(uptimeSeconds(connectedSince))
 }
 
 // whoisStaleThreshold matches the fetcher's threshold for consistency.
@@ -508,7 +517,7 @@ type StreamStats struct {
 //
 //nolint:tagliatelle // field names are the existing JSON API
 type StatsResponse struct {
-	Uptime                 string               `json:"uptime"`
+	UptimeSeconds          int64                `json:"uptime_seconds"`
 	TotalMessages          uint64               `json:"total_messages"`
 	TotalBytes             uint64               `json:"total_bytes"`
 	TotalWireBytes         uint64               `json:"total_wire_bytes"`
@@ -516,11 +525,10 @@ type StatsResponse struct {
 	MbitsPerSec            float64              `json:"mbits_per_sec"`
 	WireMbitsPerSec        float64              `json:"wire_mbits_per_sec"`
 	Connected              bool                 `json:"connected"`
-	ConnectionDuration     string               `json:"connection_duration"`
 	ReconnectCount         uint64               `json:"reconnect_count"`
 	GoVersion              string               `json:"go_version"`
 	Goroutines             int                  `json:"goroutines"`
-	MemoryUsage            string               `json:"memory_usage"`
+	MemoryUsageBytes       uint64               `json:"memory_usage_bytes"`
 	GC                     GCStats              `json:"gc"`
 	Stream                 StreamStats          `json:"stream"`
 	ASNs                   int                  `json:"asns"`
@@ -542,6 +550,9 @@ type StatsResponse struct {
 	IPv6PrefixDistribution []PrefixDistribution `json:"ipv6_prefix_distribution"`
 	WHOISStats             *WHOISStatsInfo      `json:"whois_stats,omitempty"`
 
+	// ConnectionDurationSeconds is null while the stream is not connected.
+	ConnectionDurationSeconds *int64 `json:"connection_duration_seconds"`
+
 	OriginsWithoutKeptRoute int `json:"origins_without_kept_route"`
 }
 
@@ -680,20 +691,18 @@ func (s *Server) statsResponse(
 	runtime.ReadMemStats(&memStats)
 
 	return StatsResponse{
-		Uptime:          streamUptime(streamMetrics.ConnectedSince),
+		UptimeSeconds:          uptimeSeconds(streamMetrics.ConnectedSince),
-		TotalMessages:   streamMetrics.TotalMessages,
+		TotalMessages:          streamMetrics.TotalMessages,
-		TotalBytes:      streamMetrics.TotalBytes,
+		TotalBytes:             streamMetrics.TotalBytes,
-		TotalWireBytes:  streamMetrics.TotalWireBytes,
+		TotalWireBytes:         streamMetrics.TotalWireBytes,
-		MessagesPerSec:  streamMetrics.MessagesPerSec,
+		MessagesPerSec:         streamMetrics.MessagesPerSec,
-		MbitsPerSec:     streamMetrics.BitsPerSec / bitsPerMegabit,
+		MbitsPerSec:            streamMetrics.BitsPerSec / bitsPerMegabit,
-		WireMbitsPerSec: streamMetrics.WireBitsPerSec / bitsPerMegabit,
+		WireMbitsPerSec:        streamMetrics.WireBitsPerSec / bitsPerMegabit,
-		Connected:       streamMetrics.Connected,
+		Connected:              streamMetrics.Connected,
-		ConnectionDuration: connectionDuration(
-			streamMetrics.Connected, streamMetrics.ConnectedSince),
 		ReconnectCount:         streamMetrics.ReconnectCount,
 		GoVersion:              runtime.Version(),
 		Goroutines:             runtime.NumGoroutine(),
-		MemoryUsage:            humanize.Bytes(memStats.Alloc),
+		MemoryUsageBytes:       memStats.Alloc,
 		GC:                     gcStats(&memStats),
 		Stream:                 s.streamStats(),
 		ASNs:                   dbStats.ASNs,
@@ -715,6 +724,9 @@ func (s *Server) statsResponse(
 		IPv6PrefixDistribution: prefixDistribution(counts.IPv6PrefixesByLength),
 		WHOISStats:             whoisStats,
 
+		ConnectionDurationSeconds: connectionDurationSeconds(
+			streamMetrics.Connected, streamMetrics.ConnectedSince),
+
 		OriginsWithoutKeptRoute: counts.OriginsWithoutKeptRoute,
 	}
 }
@@ -748,15 +760,14 @@ type IPLookupResponse struct {
 }
 
 // IPLookupResult is the answer for one address: its PTR names, its live route
-// and that route's AS, and the blocklists that list it. IPInfo is nil when
+// and that route's AS, and the blocklists that list it. Every result has every
-// the address has no live route, and the answer then has no route or AS
+// field. The fields of IPInfo are null when the address has no live route.
-// fields. IP hides the IPInfo field of the same name, so that an address with
-// no route has it too.
 type IPLookupResult struct {
-	*IPInfo
+	IPInfo
 
-	IP  string   `json:"ip"`
+	IP string `json:"ip"`
-	PTR []string `json:"ptr,omitempty"`
+	// PTR is empty, never nil, when the address has no PTR names.
+	PTR []string `json:"ptr"`
 
 	// Blocklists has one entry for each blocklist the address is on.
 	Blocklists []blocklist.Listing `json:"blocklists"`
@@ -814,8 +825,8 @@ func (s *Server) handleIPInfo() http.HandlerFunc {
 
 			switch {
 			case errors.Is(err, ErrNoRoute):
-				// The address still gets a result, without route fields.
+				// The address still gets a result, with every field of
-				ipInfo = nil
+				// ipInfo null.
 			case errors.Is(err, ErrInvalidIP):
 				response.Errors = append(response.Errors, ip+": "+err.Error())
 
@@ -842,8 +853,8 @@ func (s *Server) handleIPInfo() http.HandlerFunc {
 				Blocklists: s.blocklistListings(ip),
 			})
 
-			if ipInfo != nil && ipInfo.NeedsWHOISRefresh {
+			if ipInfo.NeedsWHOISRefresh {
-				refreshASNs[ipInfo.ASN] = true
+				refreshASNs[*ipInfo.ASN] = true
 			}
 		}
 
@@ -854,60 +865,72 @@ func (s *Server) handleIPInfo() http.HandlerFunc {
 	}
 }
 
-// ipInfo returns the IP lookup's answer for ip. The routing table gives the
+// ipInfo returns what the IP lookup knows about the route of ip. The routing
-// most specific prefix that holds the address, the number of peers that carry
+// table gives the most specific prefix that holds the address, the number of
-// it, the origin AS that most of them carry, and the time of its newest kept
+// peers that carry it, its origin ASes and the one that most peers carry, and
-// route. The database gives the prefix's first-seen time and the AS's WHOIS
+// the time of its newest kept route. The database gives the prefix's
-// details. It returns ErrNoRoute when no prefix holds the address, and
+// first-seen time and the AS's WHOIS details. It returns ErrNoRoute when no
-// ErrInvalidIP when ip does not parse.
+// prefix holds the address, and ErrInvalidIP when ip does not parse. With an
-func (s *Server) ipInfo(ctx context.Context, ip string) (*IPInfo, error) {
+// error, every field of the IPInfo it returns is nil.
+func (s *Server) ipInfo(ctx context.Context, ip string) (IPInfo, error) {
 	addr, err := netip.ParseAddr(ip)
 	if err != nil {
-		return nil, fmt.Errorf("%w: %s", ErrInvalidIP, ip)
+		return IPInfo{}, fmt.Errorf("%w: %s", ErrInvalidIP, ip)
 	}
 
 	summary, found := s.table.Lookup(addr)
 	if !found {
-		return nil, fmt.Errorf("%w for IP %s", ErrNoRoute, ip)
+		return IPInfo{}, fmt.Errorf("%w for IP %s", ErrNoRoute, ip)
 	}
 
 	firstSeen, err := s.db.GetPrefixFirstSeen(ctx, summary.Prefix)
 	if err != nil {
-		return nil, err
+		return IPInfo{}, err
 	}
 
 	asInfo, err := s.db.GetASWHOIS(ctx, summary.OriginASN)
 	if err != nil {
-		return nil, err
+		return IPInfo{}, err
 	}
 
-	info := &IPInfo{
+	info := IPInfo{
-		IP:                ip,
+		Netblock:          new(summary.Prefix.String()),
-		Netblock:          summary.Prefix.String(),
+		MaskLength:        new(summary.Prefix.Bits()),
-		MaskLength:        summary.Prefix.Bits(),
+		IPVersion:         new(ipVersionOf(summary.Prefix)),
-		IPVersion:         ipVersionOf(summary.Prefix),
+		NumPeers:          new(summary.Peers),
-		NumPeers:          summary.Peers,
+		ASN:               new(summary.OriginASN),
-		ASN:               summary.OriginASN,
+		NumOrigins:        new(len(summary.OriginASNs)),
-		ASName:            asInfo.ASName,
+		OriginASNs:        summary.OriginASNs,
-		Handle:            asInfo.Handle,
+		ASName:            nilIfEmpty(asInfo.ASName),
-		Description:       asInfo.Description,
+		Handle:            nilIfEmpty(asInfo.Handle),
-		OrgName:           asInfo.OrgName,
+		Description:       nilIfEmpty(asInfo.Description),
-		OrgID:             asInfo.OrgID,
+		OrgName:           nilIfEmpty(asInfo.OrgName),
-		Address:           asInfo.Address,
+		OrgID:             nilIfEmpty(asInfo.OrgID),
-		CountryCode:       asInfo.CountryCode,
+		Address:           nilIfEmpty(asInfo.Address),
-		AbuseEmail:        asInfo.AbuseEmail,
+		CountryCode:       nilIfEmpty(asInfo.CountryCode),
-		RIR:               asInfo.RIR,
+		AbuseEmail:        nilIfEmpty(asInfo.AbuseEmail),
-		FirstSeen:         firstSeen,
+		RIR:               nilIfEmpty(asInfo.RIR),
+		LastSeen:          summary.Newest,
 		NeedsWHOISRefresh: needsWHOISRefresh(asInfo),
 	}
 
-	if summary.Newest != nil {
+	if !firstSeen.IsZero() {
-		info.LastSeen = *summary.Newest
+		info.FirstSeen = &firstSeen
 	}
 
 	return info, nil
 }
 
+// nilIfEmpty returns a pointer to s, or nil when s is empty, so that JSON
+// gives a detail the database does not hold as null.
+func nilIfEmpty(s string) *string {
+	if s == "" {
+		return nil
+	}
+
+	return &s
+}
+
 // needsWHOISRefresh says whether the WHOIS details of asInfo were never
 // fetched or are older than whoisStaleThreshold. AS 0, no known origin, has
 // none to fetch.
@@ -1113,15 +1136,17 @@ func publicAddresses(addrs []string) []string {
 	return public
 }
 
-// lookupPTRNames returns the PTR records of ip without their trailing dots, or
+// lookupPTRNames returns the PTR records of ip without their trailing dots. It
-// nil when the lookup fails or runs past ptrLookupTimeout.
+// returns an empty list, never nil, when there are none, when the lookup fails
+// and when it runs past ptrLookupTimeout, so that an answer's ptr is [] rather
+// than null.
 func (s *Server) lookupPTRNames(ctx context.Context, ip string) []string {
 	ctx, cancel := context.WithTimeout(ctx, ptrLookupTimeout)
 	defer cancel()
 
 	ptrs, err := s.resolver.LookupAddr(ctx, ip)
-	if err != nil {
+	if err != nil || ptrs == nil {
-		return nil
+		return []string{}
 	}
 
 	// Remove trailing dots from PTR records

internal/server/handlers_internal_test.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"errors"
 	"html"
+	"maps"
 	"net"
 	"net/http"
 	"net/http/httptest"
@@ -72,8 +73,8 @@ func emptyTable() *routetable.Table {
 // Paths several tests request.
 const (
 	asPagePath           = "/as/64500"
+	asJSONPath           = "/api/v1/as/64500"
 	prefixLengthPagePath = "/prefixlength/24"
-	statusJSONPath       = "/status.json"
 	statsPath            = "/api/v1/stats"
 )
 
@@ -294,6 +295,167 @@ func TestStatsAnswerCarriesChurnPerMinute(t *testing.T) {
 	}
 }
 
+// fixedIntervalASNFetcher is a WHOIS fetcher that does nothing and reports
+// interval as its wait between fetches.
+type fixedIntervalASNFetcher struct {
+	idleASNFetcher
+
+	interval time.Duration
+}
+
+func (f fixedIntervalASNFetcher) GetStats() ASNFetcherStats {
+	return ASNFetcherStats{CurrentInterval: f.interval}
+}
+
+// unitStats holds the figures of a stats answer that carry a unit. Each is a
+// pointer, so that a figure missing from the answer is nil.
+//
+//nolint:tagliatelle // field names are the existing JSON API
+type unitStats struct {
+	UptimeSeconds    *int64  `json:"uptime_seconds"`
+	MemoryUsageBytes *uint64 `json:"memory_usage_bytes"`
+	WHOISStats       struct {
+		CurrentIntervalSeconds *float64 `json:"current_interval_seconds"`
+	} `json:"whois_stats"`
+	GC struct {
+		HeapAllocBytes uint64 `json:"heap_alloc_bytes"`
+	} `json:"gc"`
+}
+
+// TestStatsAnswersGiveUnitsInFieldNames checks that the figures of both stats
+// answers that carry a unit are numbers, with the unit at the end of their
+// names. They used to be strings with the unit in them, such as "1h18m34s" or
+// "1.1 GB" (https://git.eeqj.de/sneak/routewatch/issues/199). The stream has
+// never connected, so the uptime is 0. The memory use in /api/v1/stats is the
+// same number of bytes as its gc.heap_alloc_bytes.
+func TestStatsAnswersGiveUnitsInFieldNames(t *testing.T) {
+	t.Parallel()
+
+	const fetchInterval = 18200 * time.Millisecond
+
+	s := newServerWithTestRoutes(t)
+	s.SetASNFetcher(fixedIntervalASNFetcher{interval: fetchInterval})
+
+	for _, path := range []string{statusJSONPath, statsPath} {
+		answer := get(t, s, path).Body.Bytes()
+
+		var body struct {
+			Data unitStats `json:"data"`
+		}
+
+		err := json.Unmarshal(answer, &body)
+		if err != nil {
+			t.Errorf("%s: figures are not numbers: %v; answer %s", path, err, answer)
+
+			continue
+		}
+
+		got := body.Data
+		if got.UptimeSeconds == nil || *got.UptimeSeconds != 0 {
+			t.Errorf("%s: uptime_seconds is not 0: %s", path, answer)
+		}
+
+		if got.MemoryUsageBytes == nil || *got.MemoryUsageBytes == 0 {
+			t.Errorf("%s: memory_usage_bytes is not a number of bytes: %s",
+				path, answer)
+		}
+
+		interval := got.WHOISStats.CurrentIntervalSeconds
+		if interval == nil || *interval != fetchInterval.Seconds() {
+			t.Errorf("%s: whois_stats.current_interval_seconds is not %v: %s",
+				path, fetchInterval.Seconds(), answer)
+		}
+
+		if path == statsPath && got.MemoryUsageBytes != nil &&
+			*got.MemoryUsageBytes != got.GC.HeapAllocBytes {
+			t.Errorf("%s: memory_usage_bytes %d, want gc.heap_alloc_bytes %d",
+				path, *got.MemoryUsageBytes, got.GC.HeapAllocBytes)
+		}
+	}
+}
+
+// TestStatsAnswerGivesConnectionDurationInSeconds checks that the
+// connection_duration_seconds of /api/v1/stats is null while the stream is not
+// connected, and a whole number of seconds once it is. It used to be the
+// string "disconnected", or a Go duration such as "1h18m34s"
+// (https://git.eeqj.de/sneak/routewatch/issues/199).
+func TestStatsAnswerGivesConnectionDurationInSeconds(t *testing.T) {
+	t.Parallel()
+
+	s := newServerWithTestRoutes(t)
+
+	connectionDuration := func() json.RawMessage {
+		answer := get(t, s, statsPath).Body.Bytes()
+
+		var body struct {
+			Data map[string]json.RawMessage `json:"data"`
+		}
+
+		err := json.Unmarshal(answer, &body)
+		if err != nil {
+			t.Fatalf("decoding the answer: %v; answer %s", err, answer)
+		}
+
+		duration, ok := body.Data["connection_duration_seconds"]
+		if !ok {
+			t.Fatalf("no connection_duration_seconds: %s", answer)
+		}
+
+		return duration
+	}
+
+	disconnected := connectionDuration()
+	if string(disconnected) != "null" {
+		t.Errorf("disconnected: connection_duration_seconds = %s, want null",
+			disconnected)
+	}
+
+	s.streamer.GetMetricsTracker().SetConnected(true)
+
+	var seconds int64
+
+	connected := connectionDuration()
+
+	err := json.Unmarshal(connected, &seconds)
+	if err != nil || seconds != 0 {
+		t.Errorf("just connected: connection_duration_seconds = %s, want 0",
+			connected)
+	}
+}
+
+// TestStreamDurationsCountSeconds checks that the uptime and the connection
+// duration of a stream that connected 90 seconds ago are both 90. A stream
+// that has never connected has an uptime of 0, and one that is not connected
+// has no connection duration.
+func TestStreamDurationsCountSeconds(t *testing.T) {
+	t.Parallel()
+
+	const connectedFor = 90 * time.Second
+
+	connectedSince := time.Now().Add(-connectedFor)
+	want := int64(connectedFor / time.Second)
+
+	if got := uptimeSeconds(connectedSince); got != want {
+		t.Errorf("uptimeSeconds = %d, want %d", got, want)
+	}
+
+	if got := uptimeSeconds(time.Time{}); got != 0 {
+		t.Errorf("uptimeSeconds before any connection = %d, want 0", got)
+	}
+
+	switch got := connectionDurationSeconds(true, connectedSince); {
+	case got == nil:
+		t.Errorf("connectionDurationSeconds = nil, want %d", want)
+	case *got != want:
+		t.Errorf("connectionDurationSeconds = %d, want %d", *got, want)
+	}
+
+	if got := connectionDurationSeconds(false, connectedSince); got != nil {
+		t.Errorf("connectionDurationSeconds while not connected = %d, want nil",
+			*got)
+	}
+}
+
 // newTestTable returns a routing table that holds a route for testPrefixV4,
 // with origin AS 64500, and one for testPrefixV6, with origin AS 64501.
 func newTestTable() *routetable.Table {
@@ -765,7 +927,7 @@ func TestRoutesAnswer504WhenDatabaseReadIsCutOff(t *testing.T) {
 		{path: "/ip/" + addrInTestPrefixV4, wantJSONBody: true},
 		{path: statsPath, wantJSONBody: true},
 		{path: "/api/v1/ip/" + addrInTestPrefixV4, wantJSONBody: true},
-		{path: "/api/v1/as/64500", wantJSONBody: true},
+		{path: asJSONPath, wantJSONBody: true},
 	}
 
 	for _, tt := range tests {
@@ -946,10 +1108,10 @@ func TestJSONRoutesDoNotSendErrorDetails(t *testing.T) {
 		path     string
 		wantCode int
 	}{
-		{"/.well-known/healthcheck.json", http.StatusServiceUnavailable},
+		{healthCheckPath, http.StatusServiceUnavailable},
 		{statusJSONPath, http.StatusInternalServerError},
 		{statsPath, http.StatusInternalServerError},
-		{"/api/v1/as/64500", http.StatusInternalServerError},
+		{asJSONPath, http.StatusInternalServerError},
 		{"/api/v1/ip/" + addrInTestPrefixV4, http.StatusInternalServerError},
 		{"/api/v1/prefix/foo/24", http.StatusBadRequest},
 	}
@@ -1219,7 +1381,8 @@ func TestIPLookupKeepsRouteWhenPTRLookupDoesNotAnswer(t *testing.T) {
 		t.Fatalf("decoding the answer %q: %v", rec.Body, err)
 	}
 
-	if len(body.Data.Results) != 1 || body.Data.Results[0].Netblock != testPrefixV4 {
+	if len(body.Data.Results) != 1 || body.Data.Results[0].Netblock == nil ||
+		*body.Data.Results[0].Netblock != testPrefixV4 {
 		t.Errorf("answer %s, want one result in %s", rec.Body, testPrefixV4)
 	}
 }
@@ -1311,12 +1474,39 @@ func TestIPLookupReportsBlocklists(t *testing.T) {
 	}
 }
 
+// jsonNull is how JSON writes a field without a value.
+const jsonNull = "null"
+
+// jsonEmptyList is how JSON writes an empty list.
+const jsonEmptyList = "[]"
+
+// resultFields decodes an IP lookup answer and returns each of its results as
+// its JSON fields.
+func resultFields(t *testing.T, answer []byte) []map[string]json.RawMessage {
+	t.Helper()
+
+	var body struct {
+		Data struct {
+			Results []map[string]json.RawMessage `json:"results"`
+		} `json:"data"`
+	}
+
+	err := json.Unmarshal(answer, &body)
+	if err != nil {
+		t.Fatalf("decoding the answer %s: %v", answer, err)
+	}
+
+	return body.Data.Results
+}
+
 // TestIPLookupReportsBlocklistsOfAnAddressWithNoRoute looks up a listed
 // address that has no live route, alone and beside a routed address. Each
-// answer is 200 and has a result for the address, with its blocklists and no
+// answer is 200 and has a result for the address, with its blocklists and
-// route fields. Before the fix the lookup of that address alone answered
+// every route field set to null. Before the fix the lookup of that address
-// 404, and beside a routed address it was only named in errors, so its
+// alone answered 404, and beside a routed address it was only named in
-// blocklists were never reported.
+// errors, so its blocklists were never reported. After that fix the result
+// still left out the route fields
+// (https://git.eeqj.de/sneak/routewatch/issues/200).
 func TestIPLookupReportsBlocklistsOfAnAddressWithNoRoute(t *testing.T) {
 	t.Parallel()
 
@@ -1324,6 +1514,15 @@ func TestIPLookupReportsBlocklistsOfAnAddressWithNoRoute(t *testing.T) {
 	s.resolver = &fakeResolver{}
 	s.SetBlocklists(fakeBlocklists{})
 
+	// routeFields are the fields of a result that come from the address's
+	// route and that route's origin AS.
+	routeFields := []string{
+		"netblock", "mask_length", "ip_version", "num_peers", "asn",
+		"num_origins", "origin_asns", "as_name", "handle", "description",
+		"org_name", "org_id", "address", "country_code", "abuse_email", "rir",
+		"first_seen", "last_seen",
+	}
+
 	for _, target := range []string{
 		listedUnroutedAddr,
 		addrInTestPrefixV4 + "," + listedUnroutedAddr,
@@ -1354,12 +1553,21 @@ func TestIPLookupReportsBlocklistsOfAnAddressWithNoRoute(t *testing.T) {
 			continue
 		}
 
-		result := body.Data.Results[i]
+		fields := resultFields(t, rec.Body.Bytes())[i]
-		if result.IPInfo != nil {
+		for _, name := range routeFields {
-			t.Errorf("%s: result for %s has route fields %+v",
+			value, present := fields[name]
-				target, listedUnroutedAddr, result.IPInfo)
+
+			switch {
+			case !present:
+				t.Errorf("%s: the result for %s has no %s",
+					target, listedUnroutedAddr, name)
+			case string(value) != jsonNull:
+				t.Errorf("%s: %s of %s is %s, want %s",
+					target, name, listedUnroutedAddr, value, jsonNull)
+			}
 		}
 
+		result := body.Data.Results[i]
 		if len(result.Blocklists) != 1 ||
 			result.Blocklists[0].Name != testListing().Name {
 			t.Errorf("%s: blocklists %+v, want [%+v]",
@@ -1368,6 +1576,76 @@ func TestIPLookupReportsBlocklistsOfAnAddressWithNoRoute(t *testing.T) {
 	}
 }
 
+// twoAddressHostName is a host name that resolves to addrInTestPrefixV4 and
+// listedUnroutedAddr.
+const twoAddressHostName = "two-addresses.test"
+
+// TestIPLookupResultsHaveTheSameFields looks up a host name, addresses and
+// the caller's own address, through each IP lookup route. Some of the
+// addresses have a route and some do not, and none has PTR names. Every
+// result has the same fields. Before the fix a result left out every field
+// without a value (https://git.eeqj.de/sneak/routewatch/issues/200).
+func TestIPLookupResultsHaveTheSameFields(t *testing.T) {
+	t.Parallel()
+
+	s := newServerWithTestRoutes(t)
+	s.resolver = &fakeResolver{hosts: map[string][]string{
+		twoAddressHostName: {addrInTestPrefixV4, listedUnroutedAddr},
+	}}
+	s.SetBlocklists(fakeBlocklists{})
+
+	// want is the fields of the first result.
+	var want []string
+
+	for _, path := range []string{
+		"/api/v1/ip/" + twoAddressHostName,
+		"/ip/" + addrInTestPrefixV6 + "," + listedUnroutedAddr,
+		ownAddressPath,
+	} {
+		for _, result := range resultFields(t, get(t, s, path).Body.Bytes()) {
+			got := slices.Sorted(maps.Keys(result))
+			if want == nil {
+				want = got
+			}
+
+			if !slices.Equal(got, want) {
+				t.Errorf("%s: a result has the fields %v, want %v", path, got, want)
+			}
+		}
+	}
+}
+
+// TestIPLookupOfAnAddressWithoutPTRNamesOrStoredNetblock looks up a routed
+// address that has no PTR names, and whose netblock the database has not
+// stored. Its ptr is an empty list and its first_seen is null. Before the fix
+// ptr was left out, and first_seen was 0001-01-01T00:00:00Z
+// (https://git.eeqj.de/sneak/routewatch/issues/200).
+func TestIPLookupOfAnAddressWithoutPTRNamesOrStoredNetblock(t *testing.T) {
+	t.Parallel()
+
+	s := newServerWithTestRoutes(t)
+	s.resolver = &fakeResolver{}
+
+	path := "/api/v1/ip/" + addrInTestPrefixV4
+
+	results := resultFields(t, get(t, s, path).Body.Bytes())
+	if len(results) != 1 {
+		t.Fatalf("%s: %d results, want 1", path, len(results))
+	}
+
+	want := map[string]string{
+		"ptr":        jsonEmptyList,
+		"first_seen": jsonNull,
+	}
+
+	for name, value := range want {
+		got := string(results[0][name])
+		if got != value {
+			t.Errorf("%s: %s is %s, want %s", path, name, got, value)
+		}
+	}
+}
+
 // TestIPLookupAnswersMayBeCached checks the Cache-Control header of the IP
 // lookup answers. Caches may keep them for the blocklists' shortest interval,
 // and only the caller's own browser may keep the answer about the caller's

internal/server/handlers_table_internal_test.go

@@ -4,6 +4,8 @@ import (
 	"encoding/json"
 	"net/http"
 	"net/http/httptest"
+	"net/netip"
+	"reflect"
 	"slices"
 	"strconv"
 	"strings"
@@ -75,9 +77,10 @@ func get(t *testing.T, s *Server, path string) *httptest.ResponseRecorder {
 
 // TestIPLookupGivesTheOriginMostPeersCarry looks up an address in a prefix
 // with two origin ASes, through each IP lookup route. The answer names the
-// origin AS that more peers carry, counts every peer, and gives the time of
+// origin AS that more peers carry, counts every peer, lists both origin ASes,
-// the prefix's newest kept route. The prefix's first-seen time and the AS's
+// and gives the time of the prefix's newest kept route. The prefix's
-// WHOIS details come from the database.
+// first-seen time and the AS's WHOIS details come from the database. A WHOIS
+// detail the database does not hold is null.
 func TestIPLookupGivesTheOriginMostPeersCarry(t *testing.T) {
 	t.Parallel()
 
@@ -105,6 +108,26 @@ func TestIPLookupGivesTheOriginMostPeersCarry(t *testing.T) {
 		t.Fatalf("UpdateASNWHOIS: %v", err)
 	}
 
+	// The details the database does not hold, such as org_name, are null.
+	want := IPInfo{
+		Netblock:    new(testPrefixV4),
+		MaskLength:  new(netip.MustParsePrefix(testPrefixV4).Bits()),
+		IPVersion:   new(ipVersionV4),
+		NumPeers:    new(4),
+		ASN:         new(mostPeersASN),
+		NumOrigins:  new(2),
+		OriginASNs:  []int{mostPeersASN, fewerPeersASN},
+		ASName:      &whois.ASName,
+		CountryCode: &whois.CountryCode,
+		FirstSeen:   &firstSeen,
+		LastSeen:    new(testRouteTime(5)),
+	}
+
+	wantJSON, err := json.Marshal(want)
+	if err != nil {
+		t.Fatalf("encoding %+v: %v", want, err)
+	}
+
 	// ownAddressPath looks up the request's own address, which httptest
 	// gives as addrInTestPrefixV4.
 	for _, path := range []string{
@@ -115,22 +138,15 @@ func TestIPLookupGivesTheOriginMostPeersCarry(t *testing.T) {
 			Data IPLookupResponse `json:"data"`
 		}
 
-		err := json.Unmarshal(get(t, s, path).Body.Bytes(), &body)
+		answer := get(t, s, path).Body.Bytes()
-		if err != nil || len(body.Data.Results) != 1 ||
+
-			body.Data.Results[0].IPInfo == nil {
+		err := json.Unmarshal(answer, &body)
-			t.Fatalf("%s: answer %+v (%v), want one result with a route",
+		if err != nil || len(body.Data.Results) != 1 {
-				path, body.Data, err)
+			t.Fatalf("%s: answer %s (%v), want one result", path, answer, err)
 		}
 
-		got := body.Data.Results[0].IPInfo
+		if !reflect.DeepEqual(body.Data.Results[0].IPInfo, want) {
-		if got.Netblock != testPrefixV4 || got.ASN != mostPeersASN ||
+			t.Errorf("%s: answer %s, want the fields %s", path, answer, wantJSON)
-			got.NumPeers != 4 || !got.LastSeen.Equal(testRouteTime(5)) ||
-			!got.FirstSeen.Equal(firstSeen) || got.ASName != whois.ASName ||
-			got.CountryCode != whois.CountryCode {
-			t.Errorf("%s: route %+v, want %s from AS%d, 4 peers, last seen %v, "+
-				"first seen %v, %s in %s", path, *got, testPrefixV4,
-				mostPeersASN, testRouteTime(5), firstSeen, whois.ASName,
-				whois.CountryCode)
 		}
 	}
 }

internal/server/home.go

@@ -0,0 +1,206 @@
+package server
+
+import (
+	"context"
+	"html/template"
+	"net/http"
+	"slices"
+	"time"
+
+	"git.eeqj.de/sneak/routewatch/internal/database"
+	"git.eeqj.de/sneak/routewatch/internal/routetable"
+	"git.eeqj.de/sneak/routewatch/internal/templates"
+	asinfo "git.eeqj.de/sneak/routewatch/pkg/asinfo"
+)
+
+const (
+	// homeCardsRefreshInterval is how often the server works out the home
+	// page's cards again. Some of their figures take a walk over the whole
+	// routing table, so no request works them out.
+	homeCardsRefreshInterval = time.Minute
+
+	// homeCardsDatabaseTimeout is how long the database read behind the
+	// cards of the newest and the oldest AS may take.
+	homeCardsDatabaseTimeout = 4 * time.Second
+
+	// maxListedEntries is how many entries the bogon and multiple-origin
+	// pages list at most.
+	maxListedEntries = 1000
+)
+
+// homeCards is what the home page's cards show. The bogon and multiple-origin
+// pages list the entries their cards count. The server works it out every
+// homeCardsRefreshInterval and serves this copy in between.
+type homeCards struct {
+	routetable.Overview
+
+	// NewestAS and OldestAS are the ASes the asns table last saw most
+	// recently and longest ago. They are nil when the database did not
+	// answer or holds no AS.
+	NewestAS *database.ASN
+	OldestAS *database.ASN
+
+	// WellKnownNetworks are the networks of wellKnownASNs, newest update
+	// first.
+	WellKnownNetworks []wellKnownNetwork
+}
+
+// wellKnownNetwork is one network on the home page's card of well-known
+// networks.
+type wellKnownNetwork struct {
+	ASN int
+	// Name is its description in the AS list built into RouteWatch.
+	Name string
+	// Prefixes is how many prefixes it originates.
+	Prefixes int
+	// Newest is the time of its newest kept route, or nil when it keeps none.
+	Newest *time.Time
+}
+
+// listPageData is what the bogon and multiple-origin pages are rendered with.
+type listPageData struct {
+	// CSPNonce is the nonce the page's style block carries.
+	CSPNonce string
+	// Cards is the copy of the home page's cards, or nil before the server
+	// has first worked them out.
+	Cards *homeCards
+}
+
+// The AS numbers of the networks the home page lists as well known.
+const (
+	appleASN             = 714
+	googleASN            = 15169
+	amazonASN            = 16509
+	microsoftASN         = 8075
+	metaASN              = 32934
+	cloudflareASN        = 13335
+	akamaiASN            = 20940
+	netflixASN           = 2906
+	dodNetworkInfoCtrASN = 721
+	cogentASN            = 174
+	hurricaneElectricASN = 6939
+	level3ASN            = 3356
+	arelionASN           = 1299
+	nttASN               = 2914
+	mitASN               = 3
+)
+
+// wellKnownASNs returns the AS numbers of the networks the home page lists as
+// well known: large companies, large transit networks, the US Department of
+// Defense's Network Information Center and a university.
+func wellKnownASNs() []int {
+	return []int{
+		appleASN, googleASN, amazonASN, microsoftASN, metaASN, cloudflareASN,
+		akamaiASN, netflixASN, dodNetworkInfoCtrASN, cogentASN,
+		hurricaneElectricASN, level3ASN, arelionASN, nttASN, mitASN,
+	}
+}
+
+// keepHomeCardsFresh works out the home page's cards now, and again every
+// interval until ctx ends.
+func (s *Server) keepHomeCardsFresh(ctx context.Context, interval time.Duration) {
+	ticker := time.NewTicker(interval)
+	defer ticker.Stop()
+
+	for {
+		s.refreshHomeCards(ctx)
+
+		select {
+		case <-ctx.Done():
+			return
+		case <-ticker.C:
+		}
+	}
+}
+
+// refreshHomeCards works out the home page's cards and keeps them for the
+// pages to serve. When the database does not answer, the failure is logged
+// and the cards of the newest and the oldest AS stay empty.
+func (s *Server) refreshHomeCards(ctx context.Context) {
+	cards := &homeCards{
+		Overview:          s.table.Overview(maxListedEntries),
+		WellKnownNetworks: s.wellKnownNetworks(),
+	}
+
+	ctx, cancel := context.WithTimeout(ctx, homeCardsDatabaseTimeout)
+	defer cancel()
+
+	newest, oldest, err := s.db.GetLastSeenASes(ctx)
+	if err != nil {
+		s.logger.Warn("Failed to read the newest and the oldest AS", "error", err)
+	} else {
+		cards.NewestAS, cards.OldestAS = newest, oldest
+	}
+
+	s.cards.Store(cards)
+}
+
+// wellKnownNetworks returns the networks of wellKnownASNs, each with how many
+// prefixes it originates and the time of its newest kept route. They come
+// newest first, and those that keep no route last.
+func (s *Server) wellKnownNetworks() []wellKnownNetwork {
+	asns := wellKnownASNs()
+	networks := make([]wellKnownNetwork, 0, len(asns))
+
+	for _, asn := range asns {
+		originated := s.table.OriginatedPrefixes(asn)
+		network := wellKnownNetwork{ASN: asn, Prefixes: len(originated)}
+
+		if info, ok := asinfo.Get(asn); ok {
+			network.Name = info.Description
+		}
+
+		for _, p := range originated {
+			if p.Newest != nil &&
+				(network.Newest == nil || p.Newest.After(*network.Newest)) {
+				network.Newest = p.Newest
+			}
+		}
+
+		networks = append(networks, network)
+	}
+
+	slices.SortStableFunc(networks, func(a, b wellKnownNetwork) int {
+		switch {
+		case a.Newest == nil && b.Newest == nil:
+			return 0
+		case a.Newest == nil:
+			return 1
+		case b.Newest == nil:
+			return -1
+		}
+
+		return b.Newest.Compare(*a.Newest)
+	})
+
+	return networks
+}
+
+// handleBogons returns a handler that serves the page listing the bogon
+// announcements.
+func (s *Server) handleBogons() http.HandlerFunc {
+	return s.listPageHandler(templates.BogonsTemplate())
+}
+
+// handleMultipleOrigins returns a handler that serves the page listing the
+// prefixes announced by more than one origin AS.
+func (s *Server) handleMultipleOrigins() http.HandlerFunc {
+	return s.listPageHandler(templates.MultipleOriginsTemplate())
+}
+
+// listPageHandler returns a handler that renders tmpl, a page that lists
+// entries the home page's cards count, from the copy of the cards.
+func (s *Server) listPageHandler(tmpl *template.Template) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Content-Type", "text/html; charset=utf-8")
+
+		err := tmpl.Execute(w, listPageData{
+			CSPNonce: cspNonce(r.Context()),
+			Cards:    s.cards.Load(),
+		})
+		if err != nil {
+			s.logger.Error("Failed to render a list page", "error", err)
+			http.Error(w, "Internal Server Error", http.StatusInternalServerError)
+		}
+	}
+}

internal/server/home_internal_test.go

@@ -0,0 +1,358 @@
+package server
+
+import (
+	"context"
+	"net/netip"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	"git.eeqj.de/sneak/routewatch/internal/database"
+	"git.eeqj.de/sneak/routewatch/internal/routetable"
+)
+
+// The ASes of the routing table that newCardsTable fills. Each card test
+// finds one of them on its card.
+const (
+	twoPrefixASN   = 13335 // originates two prefixes, the most
+	newestRouteASN = 15169 // the newest route
+	oldestRouteASN = 3     // the oldest route
+	secondOrigin   = 16509 // a second origin AS of twoPrefixASN's prefix
+	privateUseASN  = 64512 // reserved, so its route is a bogon announcement
+)
+
+// Paths of the pages that list what two of the home page's cards count.
+const (
+	bogonsPath          = "/bogons"
+	multipleOriginsPath = "/multiple-origins"
+)
+
+// cardsNotReadyText is what the pages say before the cards are first worked
+// out.
+const cardsNotReadyText = "being worked out"
+
+// newCardsTable returns a routing table in which:
+//   - twoPrefixASN originates 1.0.0.0/24 and 1.0.4.0/22;
+//   - secondOrigin originates 1.0.0.0/24 too, which so has two origin ASes;
+//   - newestRouteASN's 8.8.8.0/24 has the newest route;
+//   - oldestRouteASN's 18.0.0.0/8 has the oldest;
+//   - privateUseASN originates 10.0.0.0/8, carried by two peers: a bogon
+//     announcement for both its prefix and its AS.
+//
+// The last four ASes originate one prefix each.
+func newCardsTable() *routetable.Table {
+	table := emptyTable()
+	announce(table, "1.0.0.0/24", twoPrefixASN, testPeer(1), testRouteTime(10))
+	announce(table, "1.0.4.0/22", twoPrefixASN, testPeer(1), testRouteTime(5))
+	announce(table, "1.0.0.0/24", secondOrigin, testPeer(3), testRouteTime(12))
+	announce(table, "8.8.8.0/24", newestRouteASN, testPeer(2), testRouteTime(20))
+	announce(table, "18.0.0.0/8", oldestRouteASN, testPeer(2), testRouteTime(1))
+	announce(table, "10.0.0.0/8", privateUseASN, testPeer(1), testRouteTime(15))
+	announce(table, "10.0.0.0/8", privateUseASN, testPeer(2), testRouteTime(15))
+
+	return table
+}
+
+// homeCard returns the HTML of the home page's card with heading, up to the
+// end of the card.
+func homeCard(t *testing.T, page, heading string) string {
+	t.Helper()
+
+	_, card, found := strings.Cut(page, "<h2>"+heading+"</h2>")
+	if !found {
+		t.Fatalf("the home page has no card %q", heading)
+	}
+
+	card, _, _ = strings.Cut(card, "</div>")
+
+	return card
+}
+
+// asLink returns the HTML attribute of a link to the AS page of asn.
+func asLink(asn int) string {
+	return `href="/as/` + strconv.Itoa(asn) + `"`
+}
+
+// TestHomePageCardsShowTheTableFigures fills a routing table and the asns
+// table, works out the cards, and checks that each card shows its figure.
+func TestHomePageCardsShowTheTableFigures(t *testing.T) {
+	t.Parallel()
+
+	const (
+		newestSeenASN = 6939
+		oldestSeenASN = 174
+	)
+
+	s := newServerWithTable(t, newCardsTable())
+
+	err := s.db.GetOrCreateASNBatch(map[int]database.SeenTimes{
+		newestSeenASN: {First: testRouteTime(0), Last: testRouteTime(30)},
+		oldestSeenASN: {First: testRouteTime(-30), Last: testRouteTime(-30)},
+	})
+	if err != nil {
+		t.Fatalf("GetOrCreateASNBatch: %v", err)
+	}
+
+	s.refreshHomeCards(t.Context())
+
+	page := get(t, s, "/").Body.String()
+
+	tests := []struct {
+		heading string
+		want    []string
+	}{
+		{"Newest Updated Route", []string{
+			"8.8.8.0/24", asLink(newestRouteASN),
+			testRouteTime(20).Format(routeTimeFormat),
+		}},
+		{"Oldest Updated Route", []string{
+			"18.0.0.0/8", asLink(oldestRouteASN),
+			testRouteTime(1).Format(routeTimeFormat),
+		}},
+		{"Newest Updated AS", []string{
+			asLink(newestSeenASN), testRouteTime(30).Format(routeTimeFormat),
+		}},
+		{"Oldest Updated AS", []string{
+			asLink(oldestSeenASN), testRouteTime(-30).Format(routeTimeFormat),
+		}},
+		{"AS with the Most Prefixes", []string{
+			asLink(twoPrefixASN), "Prefixes it originates: 2",
+		}},
+		{"ASes with the Fewest Prefixes", []string{
+			"ASes that originate a single prefix: 4", asLink(newestRouteASN),
+			"8.8.8.0/24",
+		}},
+		{"Bogon Announcements", []string{`href="/bogons">1<`}},
+		{"Prefixes with Several Origins", []string{`href="/multiple-origins">1<`}},
+	}
+
+	for _, tc := range tests {
+		card := homeCard(t, page, tc.heading)
+		for _, want := range tc.want {
+			if !strings.Contains(card, want) {
+				t.Errorf("card %q does not hold %s: %s", tc.heading, want, card)
+			}
+		}
+	}
+
+	// The well-known networks come newest update first, and those without
+	// a route after them.
+	networks := homeCard(t, page, "Well-Known Networks")
+	order := []int{newestRouteASN, secondOrigin, twoPrefixASN, oldestRouteASN, 714}
+	last := -1
+
+	for _, asn := range order {
+		i := strings.Index(networks, asLink(asn))
+		if i <= last {
+			t.Fatalf("well-known networks: AS%d is not after the ASes before "+
+				"it in %v: %s", asn, order, networks)
+		}
+
+		last = i
+	}
+
+	if !strings.Contains(networks, "<td>2</td>") {
+		t.Errorf("well-known networks: no network with 2 prefixes: %s", networks)
+	}
+}
+
+// TestListPagesListTheirEntries checks the rows of the bogon and multiple-origin
+// pages for the table of newCardsTable.
+func TestListPagesListTheirEntries(t *testing.T) {
+	t.Parallel()
+
+	s := newServerWithTable(t, newCardsTable())
+	s.refreshHomeCards(t.Context())
+
+	pages := map[string][]string{
+		bogonsPath: {
+			"Bogon announcements: 1.", "10.0.0.0/8", asLink(privateUseASN),
+			"<td>2</td>",
+			"Private-Use (10.0.0.0/8); Private-Use (AS64512-AS65534)",
+		},
+		multipleOriginsPath: {
+			"Prefixes announced by more than one origin AS: 1.", "1.0.0.0/24",
+			asLink(twoPrefixASN), asLink(secondOrigin), ">1 peer<",
+		},
+	}
+
+	for path, wants := range pages {
+		page := get(t, s, path).Body.String()
+		for _, want := range wants {
+			if !strings.Contains(page, want) {
+				t.Errorf("%s does not hold %s", path, want)
+			}
+		}
+	}
+}
+
+// TestListPagesListAtMostMaxListedEntries fills a table with more prefixes than
+// the list pages list, each announced by two origin ASes in reserved address
+// space. Each page lists maxListedEntries of them and gives how many there are
+// in all.
+func TestListPagesListAtMostMaxListedEntries(t *testing.T) {
+	t.Parallel()
+
+	const prefixCount = maxListedEntries + 1
+
+	table := emptyTable()
+	addr := netip.MustParseAddr("10.0.0.0")
+
+	for range prefixCount {
+		prefix := netip.PrefixFrom(addr, addr.BitLen()).String()
+		announce(table, prefix, twoPrefixASN, testPeer(1), testRouteTime(0))
+		announce(table, prefix, secondOrigin, testPeer(2), testRouteTime(0))
+
+		addr = addr.Next()
+	}
+
+	s := newServerWithTable(t, table)
+	s.refreshHomeCards(t.Context())
+
+	listed := "The first " + strconv.Itoa(maxListedEntries) + " are listed"
+	tests := []struct {
+		path  string
+		total string
+	}{
+		{bogonsPath, "Bogon announcements: " + strconv.Itoa(2*prefixCount) + "."},
+		{multipleOriginsPath, "Prefixes announced by more than one origin AS: " +
+			strconv.Itoa(prefixCount) + "."},
+	}
+
+	for _, tc := range tests {
+		page := get(t, s, tc.path).Body.String()
+
+		rows := strings.Count(page, `class="prefix-link"`)
+		if rows != maxListedEntries {
+			t.Errorf("%s lists %d entries, want %d", tc.path, rows,
+				maxListedEntries)
+		}
+
+		if !strings.Contains(page, tc.total) || !strings.Contains(page, listed) {
+			t.Errorf("%s does not say %q and %q", tc.path, tc.total, listed)
+		}
+	}
+}
+
+// TestPagesServeTheCopyOfTheCards checks that the pages show the cards as they
+// were last worked out, not as the routing table is now, and that they say so
+// before the cards are first worked out.
+func TestPagesServeTheCopyOfTheCards(t *testing.T) {
+	t.Parallel()
+
+	table := emptyTable()
+	announce(table, "1.0.0.0/24", twoPrefixASN, testPeer(1), testRouteTime(0))
+
+	s := newServerWithTable(t, table)
+
+	for _, path := range []string{"/", bogonsPath, multipleOriginsPath} {
+		if !strings.Contains(get(t, s, path).Body.String(), cardsNotReadyText) {
+			t.Errorf("%s does not say the cards are %s", path, cardsNotReadyText)
+		}
+	}
+
+	s.refreshHomeCards(t.Context())
+	announce(table, "8.8.8.0/24", newestRouteASN, testPeer(2), testRouteTime(1))
+
+	card := homeCard(t, get(t, s, "/").Body.String(), "Newest Updated Route")
+	if !strings.Contains(card, "1.0.0.0/24") {
+		t.Errorf("before the cards are worked out again, the newest route "+
+			"is not the one they were worked out with: %s", card)
+	}
+
+	s.refreshHomeCards(t.Context())
+
+	card = homeCard(t, get(t, s, "/").Body.String(), "Newest Updated Route")
+	if !strings.Contains(card, "8.8.8.0/24") {
+		t.Errorf("after the cards are worked out again, the newest route is "+
+			"not the table's: %s", card)
+	}
+}
+
+// TestKeepHomeCardsFreshWorksThemOutEveryInterval runs keepHomeCardsFresh with
+// a short interval. It works the cards out at once, again after the table
+// changes, and stops when its context ends.
+func TestKeepHomeCardsFreshWorksThemOutEveryInterval(t *testing.T) {
+	t.Parallel()
+
+	const (
+		interval = 10 * time.Millisecond
+		maxWait  = 5 * time.Second
+	)
+
+	table := emptyTable()
+	announce(table, "1.0.0.0/24", twoPrefixASN, testPeer(1), testRouteTime(0))
+
+	s := newServerWithTable(t, table)
+
+	ctx, cancel := context.WithCancel(t.Context())
+	stopped := make(chan struct{})
+
+	go func() {
+		s.keepHomeCardsFresh(ctx, interval)
+		close(stopped)
+	}()
+
+	newestRouteASNIs := func(asn int) bool {
+		cards := s.cards.Load()
+
+		return cards != nil && cards.NewestRoute != nil &&
+			cards.NewestRoute.OriginASN == asn
+	}
+
+	waitUntil(t, maxWait, func() bool { return newestRouteASNIs(twoPrefixASN) })
+
+	announce(table, "8.8.8.0/24", newestRouteASN, testPeer(2), testRouteTime(1))
+	waitUntil(t, maxWait, func() bool { return newestRouteASNIs(newestRouteASN) })
+
+	cancel()
+
+	select {
+	case <-stopped:
+	case <-time.After(maxWait):
+		t.Fatal("keepHomeCardsFresh did not stop when its context ended")
+	}
+}
+
+// TestStartedServerWorksOutTheCards starts a server and waits until its home
+// page shows the cards.
+func TestStartedServerWorksOutTheCards(t *testing.T) {
+	t.Parallel()
+
+	const maxWait = 5 * time.Second
+
+	s := newServerWithTable(t, newCardsTable())
+
+	err := s.Start(t.Context())
+	if err != nil {
+		t.Fatalf("Start: %v", err)
+	}
+
+	defer func() { _ = s.Stop(context.Background()) }()
+
+	waitUntil(t, maxWait, func() bool {
+		return !strings.Contains(get(t, s, "/").Body.String(), cardsNotReadyText)
+	})
+
+	card := homeCard(t, get(t, s, "/").Body.String(), "Newest Updated Route")
+	if !strings.Contains(card, "8.8.8.0/24") {
+		t.Errorf("the newest route is not the table's: %s", card)
+	}
+}
+
+// waitUntil fails the test unless done reports true within maxWait.
+func waitUntil(t *testing.T, maxWait time.Duration, done func() bool) {
+	t.Helper()
+
+	const pollInterval = 5 * time.Millisecond
+
+	deadline := time.Now().Add(maxWait)
+	for !done() {
+		if time.Now().After(deadline) {
+			t.Fatalf("the cards did not change within %s", maxWait)
+		}
+
+		time.Sleep(pollInterval)
+	}
+}

internal/server/middleware.go

@@ -16,6 +16,7 @@ import (
 	"time"
 
 	"github.com/go-chi/chi/v5"
+	"github.com/go-chi/chi/v5/middleware"
 )
 
 // responseWriter wraps http.ResponseWriter to capture the response
@@ -53,6 +54,15 @@ func (rw *responseWriter) Header() http.Header {
 	return rw.ResponseWriter.Header()
 }
 
+// The @meta object JSONResponseMiddleware adds to a JSON answer: its key, and
+// the keys of its fields.
+const (
+	jsonKeyMeta            = "@meta"
+	metaKeyTimeZone        = "time_zone"
+	metaKeyAPIVersion      = "api_version"
+	metaKeyExecutionTimeMs = "execution_time_ms"
+)
+
 // JSONResponseMiddleware is an HTTP middleware that wraps all JSON responses
 // with a @meta field containing execution metadata. The metadata includes the
 // time zone (always UTC), API version, and request execution time in milliseconds.
@@ -106,10 +116,10 @@ func JSONResponseMiddleware(next http.Handler) http.Handler {
 		}
 
 		// Add @meta field
-		originalResponse["@meta"] = map[string]any{
+		originalResponse[jsonKeyMeta] = map[string]any{
-			"time_zone":      "UTC",
+			metaKeyTimeZone:        "UTC",
-			"api_version":    1,
+			metaKeyAPIVersion:      1,
-			"execution_time": fmt.Sprintf("%d ms", execTime.Milliseconds()),
+			metaKeyExecutionTimeMs: execTime.Milliseconds(),
 		}
 
 		// Write the enhanced response
@@ -145,7 +155,8 @@ func deadlinePassed(ctx context.Context) bool {
 // has passed, it answers 504 with the error message "Request timeout". A 4xx
 // keeps its status, with the status's standard text as the message. For other
 // errors, it returns "Internal server error", with status 500 if the original
-// status was 200.
+// status was 200. A panic in the handler answers 500 with "Internal server
+// error" too.
 //
 // Non-JSON responses are passed through unchanged.
 func JSONValidationMiddleware(next http.Handler) http.Handler {
@@ -157,8 +168,9 @@ func JSONValidationMiddleware(next http.Handler) http.Handler {
 			statusCode:     http.StatusOK,
 		}
 
-		// Serve the request
+		// Serve the request. Recoverer logs a panic in the handler and turns it
-		next.ServeHTTP(rw, r)
+		// into a 500 without a body, which gets the JSON error body below.
+		middleware.Recoverer(next).ServeHTTP(rw, r)
 
 		// Check if it's meant to be a JSON response
 		contentType := rw.Header().Get("Content-Type")

internal/server/middleware_internal_test.go

@@ -1,25 +1,40 @@
 package server
 
 import (
+	"bytes"
+	"context"
 	"encoding/json"
+	"io"
+	"log/slog"
+	"net"
 	"net/http"
 	"net/http/httptest"
 	"net/netip"
+	"os"
+	"regexp"
 	"strings"
 	"testing"
 	"time"
+
+	"git.eeqj.de/sneak/routewatch/internal/config"
+	"git.eeqj.de/sneak/routewatch/internal/database"
+	"git.eeqj.de/sneak/routewatch/internal/logger"
+	"git.eeqj.de/sneak/routewatch/internal/metrics"
+	"git.eeqj.de/sneak/routewatch/internal/streamer"
 )
 
 // The addresses the forwarding tests use: the client a proxy names in
 // X-Forwarded-For, the range of trusted proxies, a peer inside it, and a peer
 // outside it, which lies in testPrefixV4 so that an IP lookup of it finds a
-// route.
+// route. reverseProxyPeer is a reverse proxy at a private address, as Docker
+// gives one.
 const (
 	forwardedClient   = "203.0.113.9"
 	trustedProxyRange = "10.0.0.0/8"
 	trustedPeer       = "10.0.0.2:1234"
 	untrustedPeerAddr = "192.0.2.1"
 	untrustedPeer     = untrustedPeerAddr + ":1234"
+	reverseProxyPeer  = "172.19.0.14:1234"
 )
 
 // TestResponsesCarrySecurityHeaders checks that a page, a JSON route and a
@@ -87,6 +102,219 @@ func TestJSONValidationKeeps4xxWithoutBody(t *testing.T) {
 	checkJSONErrorMessage(t, name, rec, http.StatusText(http.StatusBadRequest))
 }
 
+// TestJSONAnswersPutNoUnitInAString sends a request to each JSON route and
+// checks each answer. Its @meta.execution_time_ms is a number, and none of its
+// strings is a number with a unit, such as "12 ms", "1.1 GB" or "1h18m34s"
+// (https://git.eeqj.de/sneak/routewatch/issues/199). The health check answers
+// 503, since the stream is not connected, and the last path matches no route.
+func TestJSONAnswersPutNoUnitInAString(t *testing.T) {
+	t.Parallel()
+
+	numberWithUnit := regexp.MustCompile(
+		`^([0-9]+(\.[0-9]+)? ?(ns|µs|ms|s|m|h|B|kB|MB|GB|TB))+$`)
+
+	s := newServerWithTestRoutes(t)
+	s.resolver = &fakeResolver{}
+	s.SetASNFetcher(fixedIntervalASNFetcher{interval: time.Second})
+
+	paths := []string{
+		statusJSONPath,
+		statsPath,
+		healthCheckPath,
+		"/api/v1/ip/" + untrustedPeerAddr,
+		"/ip/" + untrustedPeerAddr,
+		asJSONPath,
+		"/api/v1/prefix/" + testPrefixV4,
+		"/api/v1/search/as?q=google",
+		"/api/v1/no-such-route",
+	}
+
+	for _, path := range paths {
+		rec := httptest.NewRecorder()
+		s.router.ServeHTTP(rec, httptest.NewRequestWithContext(
+			t.Context(), http.MethodGet, path, nil))
+
+		var answer map[string]any
+
+		err := json.Unmarshal(rec.Body.Bytes(), &answer)
+		if err != nil {
+			t.Errorf("%s: decoding the answer: %v; answer %s", path, err, rec.Body)
+
+			continue
+		}
+
+		meta, _ := answer["@meta"].(map[string]any)
+		if _, ok := meta["execution_time_ms"].(float64); !ok {
+			t.Errorf("%s: @meta.execution_time_ms is not a number: %s",
+				path, rec.Body)
+		}
+
+		for _, value := range stringsIn(answer) {
+			if numberWithUnit.MatchString(value) {
+				t.Errorf("%s: %q is a number with a unit in a string", path, value)
+			}
+		}
+	}
+}
+
+// TestJSONAnswersCarryMeta sends requests to every JSON route through the
+// server's router, and checks that each answer carries @meta with its three
+// fields. The answers include successes, and errors that the handlers, the
+// router and the middleware write. Before the fix a panic in a handler, and a
+// method /status.json or the health check does not take, answered with an
+// empty body (https://git.eeqj.de/sneak/routewatch/issues/201).
+func TestJSONAnswersCarryMeta(t *testing.T) {
+	t.Parallel()
+
+	// JSON routes whose handlers write nothing or panic, so that the JSON
+	// check on the route writes the error answer itself.
+	const (
+		writesNothingPath = "/writes-nothing.json"
+		panicsPath        = "/panics.json"
+	)
+
+	s := newServerWithTestRoutes(t)
+	s.resolver = &fakeResolver{}
+	s.streamer.GetMetricsTracker().SetConnected(true)
+	s.router.Get(writesNothingPath, JSONValidationMiddleware(http.HandlerFunc(
+		func(http.ResponseWriter, *http.Request) {})).ServeHTTP)
+	s.router.Get(panicsPath, JSONValidationMiddleware(http.HandlerFunc(
+		func(http.ResponseWriter, *http.Request) { panic(errDiskIO) })).ServeHTTP)
+
+	tests := []struct {
+		method   string
+		path     string
+		wantCode int
+	}{
+		// Answers that succeed
+		{http.MethodGet, statusJSONPath, http.StatusOK},
+		{http.MethodGet, healthCheckPath, http.StatusOK},
+		{http.MethodGet, "/ip", http.StatusOK},
+		{http.MethodGet, ownAddressPath, http.StatusOK},
+		{http.MethodGet, "/ip/" + addrInTestPrefixV4, http.StatusOK},
+		{http.MethodGet, statsPath, http.StatusOK},
+		{http.MethodGet, "/api/v1/ip/" + addrInTestPrefixV4, http.StatusOK},
+		{http.MethodGet, asJSONPath, http.StatusOK},
+		{http.MethodGet, "/api/v1/prefix/" + testPrefixV4, http.StatusOK},
+		{http.MethodGet, "/api/v1/search/as?q=google", http.StatusOK},
+		// Errors the handlers write
+		{http.MethodGet, "/ip/no-such-host.example", http.StatusBadRequest},
+		{http.MethodGet, "/api/v1/ip/no-such-host.example", http.StatusBadRequest},
+		{http.MethodGet, "/api/v1/as/foo", http.StatusBadRequest},
+		{http.MethodGet, "/api/v1/as/0", http.StatusNotFound},
+		{http.MethodGet, "/api/v1/prefix/192.0.2.0/33", http.StatusBadRequest},
+		{http.MethodGet, "/api/v1/prefix/198.51.100.0/24", http.StatusNotFound},
+		{http.MethodGet, "/api/v1/search/as", http.StatusBadRequest},
+		// Errors the router and the middleware write
+		{http.MethodGet, "/api/v1/no-such-route", http.StatusNotFound},
+		{http.MethodGet, "/ip/192.0.2.1/nothing", http.StatusNotFound},
+		{http.MethodPost, statsPath, http.StatusMethodNotAllowed},
+		{http.MethodPost, ownAddressPath, http.StatusMethodNotAllowed},
+		{http.MethodPost, statusJSONPath, http.StatusMethodNotAllowed},
+		{http.MethodPut, healthCheckPath, http.StatusMethodNotAllowed},
+		{http.MethodGet, writesNothingPath, http.StatusInternalServerError},
+		{http.MethodGet, panicsPath, http.StatusInternalServerError},
+	}
+
+	for _, tt := range tests {
+		checkAnswerCarriesMeta(t, s, httptest.NewRequestWithContext(
+			t.Context(), tt.method, tt.path, nil), tt.wantCode)
+	}
+
+	// A request whose time limit has already passed answers 504. The handlers
+	// write the answers of the first five routes, and the JSON check on the
+	// route writes the last.
+	pastTimeLimit, cancel := context.WithDeadline(t.Context(), time.Now())
+	defer cancel()
+
+	for _, path := range []string{
+		statusJSONPath, statsPath, "/ip/" + addrInTestPrefixV4,
+		"/api/v1/ip/" + addrInTestPrefixV4, asJSONPath, writesNothingPath,
+	} {
+		checkAnswerCarriesMeta(t, s, httptest.NewRequestWithContext(
+			pastTimeLimit, http.MethodGet, path, nil), http.StatusGatewayTimeout)
+	}
+
+	// With a store whose reads fail, the health check answers 503, and the
+	// handlers of the other routes 500.
+	failing := New(failingDB{}, newTestTable(),
+		streamer.New(logger.New(), metrics.New()), logger.New(), &config.Config{})
+	failing.resolver = &fakeResolver{}
+
+	checkAnswerCarriesMeta(t, failing, httptest.NewRequestWithContext(
+		t.Context(), http.MethodGet, healthCheckPath, nil),
+		http.StatusServiceUnavailable)
+
+	for _, path := range []string{
+		statusJSONPath, statsPath, asJSONPath,
+		"/api/v1/ip/" + addrInTestPrefixV4, "/ip/" + addrInTestPrefixV4,
+	} {
+		checkAnswerCarriesMeta(t, failing, httptest.NewRequestWithContext(
+			t.Context(), http.MethodGet, path, nil), http.StatusInternalServerError)
+	}
+}
+
+// checkAnswerCarriesMeta serves req through the server's router, and checks
+// that it answers wantCode with @meta and its three fields.
+func checkAnswerCarriesMeta(
+	t *testing.T, s *Server, req *http.Request, wantCode int,
+) {
+	t.Helper()
+
+	// The values README "API v1" gives the two fields that never change.
+	const (
+		wantTimeZone   = "UTC"
+		wantAPIVersion = 1
+	)
+
+	name := req.Method + " " + req.URL.String()
+
+	rec := httptest.NewRecorder()
+	s.router.ServeHTTP(rec, req)
+
+	if rec.Code != wantCode {
+		t.Errorf("%s: status %d, want %d; body %s", name, rec.Code, wantCode, rec.Body)
+	}
+
+	var answer map[string]any
+
+	err := json.Unmarshal(rec.Body.Bytes(), &answer)
+	if err != nil {
+		t.Errorf("%s: decoding the answer %q: %v", name, rec.Body, err)
+
+		return
+	}
+
+	meta, _ := answer[jsonKeyMeta].(map[string]any)
+	_, timeIsNumber := meta[metaKeyExecutionTimeMs].(float64)
+
+	if meta[metaKeyTimeZone] != wantTimeZone ||
+		meta[metaKeyAPIVersion] != float64(wantAPIVersion) || !timeIsNumber {
+		t.Errorf("%s: @meta %v, want time_zone %q, api_version %d and a "+
+			"number in execution_time_ms", name, meta, wantTimeZone, wantAPIVersion)
+	}
+}
+
+// stringsIn returns every string in a decoded JSON value, at any depth.
+func stringsIn(value any) []string {
+	var found []string
+
+	switch v := value.(type) {
+	case string:
+		found = append(found, v)
+	case []any:
+		for _, item := range v {
+			found = append(found, stringsIn(item)...)
+		}
+	case map[string]any:
+		for _, item := range v {
+			found = append(found, stringsIn(item)...)
+		}
+	}
+
+	return found
+}
+
 // TestPagesCarryTheCSPNonce checks that every script and style block of each
 // page carries the nonce its Content-Security-Policy header names, so that the
 // browser runs and applies them, that each answer has a nonce of its own, and
@@ -183,6 +411,141 @@ func TestForwardedForFromUntrustedPeerIsIgnored(t *testing.T) {
 	}
 }
 
+// TestDefaultTrustedProxiesGiveTheForwardedClient builds the server from the
+// configuration with TRUSTED_PROXIES unset. A request from a reverse proxy at
+// a private address must be looked up by /ip/, shown on the home page's card
+// and logged as the client its X-Forwarded-For names. A direct request from a
+// public address with a forged X-Forwarded-For keeps its own address. Before
+// the fix no proxy was trusted unless TRUSTED_PROXIES named it, so /ip/ gave
+// the proxy's address (https://git.eeqj.de/sneak/routewatch/issues/198).
+func TestDefaultTrustedProxiesGiveTheForwardedClient(t *testing.T) {
+	t.Setenv("PORT", "")
+	t.Setenv("XDG_DATA_HOME", "")
+
+	// t.Setenv puts the variable back when the test ends.
+	t.Setenv("TRUSTED_PROXIES", "")
+
+	err := os.Unsetenv("TRUSTED_PROXIES")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	cfg, err := config.New()
+	if err != nil {
+		t.Fatalf("config.New: %v", err)
+	}
+
+	var requestLog bytes.Buffer
+
+	s := newServerWithConfig(t, cfg, &requestLog)
+
+	tests := []struct {
+		name string
+		peer string
+		want string
+	}{
+		{"through a reverse proxy", reverseProxyPeer, forwardedClient},
+		{"direct from a public address", untrustedPeer, untrustedPeerAddr},
+	}
+
+	for _, tt := range tests {
+		requestLog.Reset()
+
+		get := func(path string) *httptest.ResponseRecorder {
+			req := httptest.NewRequestWithContext(t.Context(), http.MethodGet, path, nil)
+			req.RemoteAddr = tt.peer
+			req.Header.Set("X-Forwarded-For", forwardedClient)
+
+			rec := httptest.NewRecorder()
+			s.router.ServeHTTP(rec, req)
+
+			return rec
+		}
+
+		var answer struct {
+			Data IPLookupResponse `json:"data"`
+		}
+
+		rec := get("/ip/")
+
+		err := json.Unmarshal(rec.Body.Bytes(), &answer)
+		if err != nil {
+			t.Fatalf("%s: decoding the answer %q: %v", tt.name, rec.Body, err)
+		}
+
+		if answer.Data.Query != tt.want {
+			t.Errorf("%s: /ip/ looked up %q, want %q", tt.name, answer.Data.Query, tt.want)
+		}
+
+		page := get("/").Body.String()
+		if !strings.Contains(page, `data-client-ip="`+tt.want+`"`) {
+			t.Errorf("%s: the home page's card does not hold %s", tt.name, tt.want)
+		}
+
+		logged := loggedAddresses(requestLog.String())
+		if len(logged) == 0 {
+			t.Errorf("%s: the request log names no address", tt.name)
+		}
+
+		for _, addr := range logged {
+			if addr != tt.want {
+				t.Errorf("%s: the request log gives %s, want %s", tt.name, addr, tt.want)
+			}
+		}
+	}
+}
+
+// newServerWithConfig returns a server built with cfg, on a new database, that
+// reads the routes of newTestTable and logs its requests as JSON to
+// requestLog.
+func newServerWithConfig(
+	t *testing.T, cfg *config.Config, requestLog io.Writer,
+) *Server {
+	t.Helper()
+
+	cfg.StateDir = t.TempDir()
+
+	db, err := database.New(cfg, logger.New())
+	if err != nil {
+		t.Fatalf("database.New: %v", err)
+	}
+
+	t.Cleanup(func() { _ = db.Close() })
+
+	s := New(db, newTestTable(), streamer.New(logger.New(), metrics.New()),
+		&logger.Logger{Logger: slog.New(slog.NewJSONHandler(requestLog, nil))}, cfg)
+	s.resolver = &fakeResolver{}
+
+	return s
+}
+
+// loggedAddresses returns the address each line of the JSON request log
+// names, without the port a direct request is logged with.
+func loggedAddresses(requestLog string) []string {
+	var addrs []string
+
+	for line := range strings.Lines(requestLog) {
+		//nolint:tagliatelle // the field name is the key the request log uses
+		var entry struct {
+			RemoteAddr string `json:"remote_addr"`
+		}
+
+		err := json.Unmarshal([]byte(line), &entry)
+		if err != nil || entry.RemoteAddr == "" {
+			continue
+		}
+
+		addr, _, err := net.SplitHostPort(entry.RemoteAddr)
+		if err != nil {
+			addr = entry.RemoteAddr
+		}
+
+		addrs = append(addrs, addr)
+	}
+
+	return addrs
+}
+
 // TestRealIPMiddlewareTrustsOnlyConfiguredProxies checks which address
 // RealIPMiddleware gives a request: the TCP peer, unless the peer is a trusted
 // proxy; then the last X-Forwarded-For entry that is not a trusted proxy,

internal/server/models.go

@@ -38,30 +38,37 @@ type PrefixDistribution struct {
 	Count      int `json:"count"`
 }
 
-// IPInfo represents comprehensive IP information for the /ip endpoint
+// IPInfo is what the IP lookup knows about the route of an address and that
+// route's origin AS. A field is nil, null in JSON, when its value is not known.
+// Every field is nil for an address with no route.
 //
 //nolint:tagliatelle // field names are the existing JSON API
 type IPInfo struct {
-	IP         string `json:"ip"`
+	// Netblock is the most specific prefix that holds the address.
-	Netblock   string `json:"netblock"`
+	Netblock   *string `json:"netblock"`
-	MaskLength int    `json:"mask_length"`
+	MaskLength *int    `json:"mask_length"`
-	IPVersion  int    `json:"ip_version"`
+	IPVersion  *int    `json:"ip_version"`
-	NumPeers   int    `json:"num_peers"`
+	NumPeers   *int    `json:"num_peers"`
-	// AS information
+	// ASN is the origin AS that the most peers carry the netblock with.
-	ASN         int    `json:"asn"`
+	ASN *int `json:"asn"`
-	ASName      string `json:"as_name,omitempty"`
+	// NumOrigins and OriginASNs are how many origin ASes peers carry the
-	Handle      string `json:"handle,omitempty"`
+	// netblock with, and which, in AS number order.
-	Description string `json:"description,omitempty"`
+	NumOrigins *int  `json:"num_origins"`
-	OrgName     string `json:"org_name,omitempty"`
+	OriginASNs []int `json:"origin_asns"`
-	OrgID       string `json:"org_id,omitempty"`
+	// The details the database holds about the AS in ASN.
-	Address     string `json:"address,omitempty"`
+	ASName      *string `json:"as_name"`
-	CountryCode string `json:"country_code,omitempty"`
+	Handle      *string `json:"handle"`
-	AbuseEmail  string `json:"abuse_email,omitempty"`
+	Description *string `json:"description"`
-	RIR         string `json:"rir,omitempty"`
+	OrgName     *string `json:"org_name"`
-	// Timestamps. LastSeen is zero, and left out of JSON, when the prefix
+	OrgID       *string `json:"org_id"`
-	// keeps no route.
+	Address     *string `json:"address"`
-	FirstSeen time.Time `json:"first_seen"`
+	CountryCode *string `json:"country_code"`
-	LastSeen  time.Time `json:"last_seen,omitzero"`
+	AbuseEmail  *string `json:"abuse_email"`
+	RIR         *string `json:"rir"`
+	// FirstSeen is when RouteWatch first saw the netblock. LastSeen is the
+	// time of the netblock's newest kept route.
+	FirstSeen *time.Time `json:"first_seen"`
+	LastSeen  *time.Time `json:"last_seen"`
 	// Indicates if WHOIS data needs refresh (not serialized)
 	NeedsWHOISRefresh bool `json:"-"`
 }

internal/server/routes.go

@@ -8,8 +8,8 @@ import (
 	"github.com/go-chi/chi/v5/middleware"
 )
 
-// The error messages the JSON routes under /api/v1 and /ip answer with when no
+// The error messages the JSON routes answer with when no route matches the
-// route matches the path, and when none takes the method.
+// path, and when the route does not take the method.
 const (
 	notFoundMessage         = "Not found"
 	methodNotAllowedMessage = "Method not allowed"
@@ -19,6 +19,13 @@ const (
 	jsonRoutesAllow = "GET, HEAD"
 )
 
+// The paths of the status figures and the health check, the two JSON routes
+// outside /api/v1 and /ip.
+const (
+	statusJSONPath  = "/status.json"
+	healthCheckPath = "/.well-known/healthcheck.json"
+)
+
 // setupRoutes configures the HTTP routes
 func (s *Server) setupRoutes() {
 	r := chi.NewRouter()
@@ -32,6 +39,8 @@ func (s *Server) setupRoutes() {
 	r.Use(middleware.RequestID)
 	r.Use(RealIPMiddleware(s.trustedProxies))
 	r.Use(RequestLoggerMiddleware(s.logger.Logger)) // Structured request logging
+	// Recoverer answers a panic on a page. JSONValidationMiddleware recovers a
+	// panic on a JSON route itself, so that the answer is JSON with @meta.
 	r.Use(middleware.Recoverer)
 	r.Use(JSONResponseMiddleware)
 	// Timeout must come after JSONResponseMiddleware, which sends its answer
@@ -43,11 +52,6 @@ func (s *Server) setupRoutes() {
 	// Routes
 	r.Get("/", s.handleIndex())
 	r.Get("/status", s.handleStatusHTML())
-	r.Get("/status.json", JSONValidationMiddleware(s.handleStatusJSON()).ServeHTTP)
-	r.Get(
-		"/.well-known/healthcheck.json",
-		JSONValidationMiddleware(s.handleHealthCheck()).ServeHTTP,
-	)
 
 	// AS and prefix detail pages
 	r.Get("/as/{asn}", s.handleASDetail())
@@ -55,6 +59,10 @@ func (s *Server) setupRoutes() {
 	r.Get("/prefixlength/{length}", s.handlePrefixLength())
 	r.Get("/prefixlength6/{length}", s.handlePrefixLength6())
 
+	// The pages that list what two of the home page's cards count
+	r.Get("/bogons", s.handleBogons())
+	r.Get("/multiple-origins", s.handleMultipleOrigins())
+
 	// The JSON routes answer a path or method they do not take with the JSON
 	// error body, as they answer everything else.
 	jsonNotFound := func(w http.ResponseWriter, _ *http.Request) {
@@ -66,6 +74,21 @@ func (s *Server) setupRoutes() {
 		s.writeJSONError(w, http.StatusMethodNotAllowed, methodNotAllowedMessage)
 	}
 
+	// The status figures and the health check. chi sets one 405 answer for a
+	// whole router. These two routes are on the pages' router, whose 405 stays
+	// chi's own. So each method they do not take is routed to the JSON 405
+	// here.
+	r.Get(statusJSONPath, JSONValidationMiddleware(s.handleStatusJSON()).ServeHTTP)
+	r.Get(healthCheckPath, JSONValidationMiddleware(s.handleHealthCheck()).ServeHTTP)
+
+	for _, method := range []string{
+		http.MethodPost, http.MethodPut, http.MethodPatch, http.MethodDelete,
+		http.MethodOptions, http.MethodTrace, http.MethodConnect,
+	} {
+		r.MethodFunc(method, statusJSONPath, jsonMethodNotAllowed)
+		r.MethodFunc(method, healthCheckPath, jsonMethodNotAllowed)
+	}
+
 	// IP info JSON endpoints (replaces old /ip redirect)
 	r.Route("/ip", func(r chi.Router) {
 		r.Use(JSONValidationMiddleware)

internal/server/routes_internal_test.go

@@ -17,7 +17,7 @@ func TestRoutesAnswerHEAD(t *testing.T) {
 
 	s := newServerWithTestRoutes(t)
 
-	for _, path := range []string{"/", statsPath, "/ip", "/ip/"} {
+	for _, path := range []string{"/", statusJSONPath, statsPath, "/ip", "/ip/"} {
 		rec := httptest.NewRecorder()
 		s.router.ServeHTTP(rec, httptest.NewRequestWithContext(
 			t.Context(), http.MethodHead, path, nil))
@@ -31,10 +31,13 @@ func TestRoutesAnswerHEAD(t *testing.T) {
 
 // TestJSONRoutesAnswerUnmatchedRequestsWithJSONErrors sends a method the JSON
 // routes do not take, and a path none of them matches, to each group of JSON
-// routes through the server's router. Each must answer with the JSON error
+// routes through the server's router. It also sends a method they do not take
+// to /status.json and the health check. Each must answer with the JSON error
 // body, and a 405 must name the methods the routes take in its Allow header.
 // Before the fix a 405 said "Internal server error" and a 404 was chi's plain
 // text answer (https://git.eeqj.de/sneak/routewatch/issues/111).
+// /status.json and the health check gave chi's empty 405
+// (https://git.eeqj.de/sneak/routewatch/issues/201).
 func TestJSONRoutesAnswerUnmatchedRequestsWithJSONErrors(t *testing.T) {
 	t.Parallel()
 
@@ -48,6 +51,14 @@ func TestJSONRoutesAnswerUnmatchedRequestsWithJSONErrors(t *testing.T) {
 	}{
 		{http.MethodPost, statsPath, http.StatusMethodNotAllowed, methodNotAllowedMessage},
 		{http.MethodPost, "/ip/", http.StatusMethodNotAllowed, methodNotAllowedMessage},
+		{
+			http.MethodDelete, statusJSONPath,
+			http.StatusMethodNotAllowed, methodNotAllowedMessage,
+		},
+		{
+			http.MethodOptions, healthCheckPath,
+			http.StatusMethodNotAllowed, methodNotAllowedMessage,
+		},
 		{http.MethodGet, "/api/v1/nothing", http.StatusNotFound, notFoundMessage},
 		{http.MethodGet, "/ip/192.0.2.1/nothing", http.StatusNotFound, notFoundMessage},
 	}

internal/server/server.go

@@ -1,5 +1,7 @@
 // Package server serves RouteWatch's web pages and JSON API:
 //   - the home page, the status figures and the health check
+//   - the pages that list the bogon announcements and the prefixes announced
+//     by more than one origin AS
 //   - the AS, prefix and prefix length pages, and the JSON answers behind them
 //   - the IP lookups
 //   - the AS name search
@@ -17,6 +19,7 @@ import (
 	"net/http"
 	"net/netip"
 	"strconv"
+	"sync/atomic"
 	"time"
 
 	"git.eeqj.de/sneak/routewatch/internal/blocklist"
@@ -75,6 +78,10 @@ type Server struct {
 	// resolver makes the IP lookup's DNS lookups: net.DefaultResolver, or a
 	// fake in tests
 	resolver dnsResolver
+
+	// cards is the copy of the home page's cards that the pages serve, nil
+	// until the server first works them out
+	cards atomic.Pointer[homeCards]
 }
 
 // New creates a new HTTP server that reads routes from table, the routing
@@ -103,7 +110,8 @@ func New(
 
 // Start listens on the configured port and serves HTTP in the background.
 // It returns an error if it cannot listen, for example because the port is
-// already in use. ctx bounds only opening the port, not serving.
+// already in use. ctx bounds opening the port, not serving. Once listening,
+// the server works out the home page's cards every minute until ctx ends.
 func (s *Server) Start(ctx context.Context) error {
 	const (
 		network           = "tcp"
@@ -140,6 +148,10 @@ func (s *Server) Start(ctx context.Context) error {
 		}
 	}()
 
+	go func() {
+		s.keepHomeCardsFresh(ctx, homeCardsRefreshInterval)
+	}()
+
 	return nil
 }
 

internal/templates/bogons.html

@@ -0,0 +1,170 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Bogon Announcements - RouteWatch</title>
+    <style nonce="{{.CSPNonce}}">
+        * {
+            box-sizing: border-box;
+        }
+        body {
+            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
+            margin: 0;
+            padding: 0;
+            background: #f5f5f5;
+        }
+
+        /* Navbar styles */
+        .navbar {
+            background: #2c3e50;
+            padding: 0 20px;
+            display: flex;
+            align-items: center;
+            justify-content: space-between;
+            height: 56px;
+            box-shadow: 0 2px 4px rgba(0,0,0,0.1);
+        }
+        .navbar-brand {
+            display: flex;
+            align-items: center;
+            gap: 8px;
+            font-size: 18px;
+            font-weight: 600;
+        }
+        .navbar-brand a {
+            color: white;
+            text-decoration: none;
+        }
+        .navbar-brand a:hover {
+            color: #ecf0f1;
+        }
+        .navbar-brand .by {
+            font-weight: normal;
+            color: #95a5a6;
+            font-size: 14px;
+        }
+        .navbar-brand .author {
+            color: #3498db;
+            font-weight: normal;
+        }
+        .navbar-brand .author:hover {
+            text-decoration: underline;
+        }
+        .navbar-links {
+            display: flex;
+            gap: 20px;
+        }
+        .navbar-links a {
+            color: #ecf0f1;
+            text-decoration: none;
+            font-size: 14px;
+            padding: 8px 12px;
+            border-radius: 4px;
+            transition: background-color 0.2s;
+        }
+        .navbar-links a:hover {
+            background: rgba(255,255,255,0.1);
+        }
+
+        /* Main content */
+        .main-content {
+            max-width: 1200px;
+            margin: 0 auto;
+            padding: 20px;
+        }
+        h1 {
+            color: #333;
+            margin-bottom: 10px;
+        }
+        .subtitle {
+            color: #666;
+            margin-bottom: 30px;
+        }
+        table {
+            width: 100%;
+            border-collapse: collapse;
+            background: white;
+            box-shadow: 0 2px 4px rgba(0,0,0,0.1);
+            border-radius: 8px;
+            overflow: hidden;
+        }
+        th {
+            background: #f8f9fa;
+            padding: 12px;
+            text-align: left;
+            font-weight: 600;
+            color: #333;
+            border-bottom: 2px solid #dee2e6;
+        }
+        td {
+            padding: 12px;
+            border-bottom: 1px solid #eee;
+        }
+        tr:last-child td {
+            border-bottom: none;
+        }
+        tr:hover {
+            background: #f8f9fa;
+        }
+        a {
+            color: #0066cc;
+            text-decoration: none;
+        }
+        a:hover {
+            text-decoration: underline;
+        }
+        .prefix-link {
+            font-family: 'SF Mono', Monaco, 'Cascadia Mono', 'Roboto Mono', Consolas, 'Courier New', monospace;
+        }
+    </style>
+</head>
+<body>
+    <nav class="navbar">
+        <div class="navbar-brand">
+            <a href="/">routewatch</a>
+            <span class="by">by</span>
+            <a href="https://sneak.berlin" class="author">@sneak</a>
+        </div>
+        <div class="navbar-links">
+            <a href="/">Home</a>
+            <a href="/status">Status</a>
+        </div>
+    </nav>
+
+    <main class="main-content">
+    <h1>Bogon Announcements</h1>
+    {{ with .Cards }}
+    <p class="subtitle">
+        Bogon announcements: {{ .BogonCount }}.
+        A bogon announcement is a route that announces a reserved prefix, or that comes from a reserved AS number.
+        {{ if lt (len .Bogons) .BogonCount }}The first {{ len .Bogons }} are listed, in prefix order.{{ end }}
+        The list is worked out once a minute.
+    </p>
+
+    <table>
+        <thead>
+            <tr>
+                <th>Prefix</th>
+                <th>Origin AS</th>
+                <th>Peers</th>
+                <th>Why it is a bogon</th>
+            </tr>
+        </thead>
+        <tbody>
+            {{ range .Bogons }}
+            <tr>
+                <td><a href="{{ prefixURL .Prefix.String }}" class="prefix-link">{{ .Prefix }}</a></td>
+                <td>{{ if .OriginASN }}<a href="/as/{{ .OriginASN }}">AS{{ .OriginASN }}</a>{{ else }}No known origin{{ end }}</td>
+                <td>{{ .Peers }}</td>
+                <td>{{ range $i, $reason := .Reasons }}{{ if $i }}; {{ end }}{{ $reason }}{{ end }}</td>
+            </tr>
+            {{ end }}
+        </tbody>
+    </table>
+    {{ else }}
+    <p class="subtitle">The list is being worked out. Reload the page in a minute.</p>
+    {{ end }}
+    </main>
+</body>
+</html>

internal/templates/index.html

@@ -276,6 +276,52 @@
             margin-top: 12px;
         }
 
+        /* Cards with figures of the routing table, worked out once a minute */
+        #table-cards p,
+        #well-known p {
+            margin: 0 0 8px 0;
+            font-size: 14px;
+        }
+        #table-cards a,
+        #well-known a {
+            color: #3498db;
+            text-decoration: none;
+        }
+        #table-cards a:hover,
+        #well-known a:hover {
+            text-decoration: underline;
+        }
+        #table-cards .card-figure {
+            font-size: 32px;
+            font-weight: bold;
+        }
+        #table-cards .card-detail,
+        #table-cards .card-time {
+            color: #7f8c8d;
+            font-size: 12px;
+        }
+        #table-cards .prefix {
+            font-family: 'SF Mono', Monaco, 'Cascadia Mono', 'Roboto Mono', Consolas, 'Courier New', monospace;
+        }
+        #well-known {
+            margin-bottom: 40px;
+        }
+        #well-known table {
+            width: 100%;
+            border-collapse: collapse;
+            font-size: 14px;
+        }
+        #well-known th,
+        #well-known td {
+            text-align: left;
+            padding: 8px 4px;
+            border-bottom: 1px solid #eee;
+        }
+        #well-known th {
+            color: #7f8c8d;
+            font-weight: 600;
+        }
+
         /* Footer */
         .footer {
             margin-top: 40px;
@@ -381,6 +427,109 @@
             </div>
         </div>
 
+        {{ with .Cards }}
+        <div class="search-section" id="table-cards">
+            <div class="search-card">
+                <h2>Newest Updated Route</h2>
+                {{ with .NewestRoute }}
+                <p><a href="{{ prefixURL .Prefix.String }}" class="prefix">{{ .Prefix }}</a> from {{ if .OriginASN }}<a href="/as/{{ .OriginASN }}">AS{{ .OriginASN }}</a>{{ else }}no known origin{{ end }}</p>
+                <p class="card-time">{{ .Time.UTC.Format "2006-01-02 15:04:05" }} UTC, {{ timeSince .Time }}</p>
+                {{ else }}
+                <p>The routing table keeps no route yet.</p>
+                {{ end }}
+            </div>
+
+            <div class="search-card">
+                <h2>Oldest Updated Route</h2>
+                {{ with .OldestRoute }}
+                <p><a href="{{ prefixURL .Prefix.String }}" class="prefix">{{ .Prefix }}</a> from {{ if .OriginASN }}<a href="/as/{{ .OriginASN }}">AS{{ .OriginASN }}</a>{{ else }}no known origin{{ end }}</p>
+                <p class="card-time">{{ .Time.UTC.Format "2006-01-02 15:04:05" }} UTC, {{ timeSince .Time }}</p>
+                {{ else }}
+                <p>The routing table keeps no route yet.</p>
+                {{ end }}
+            </div>
+
+            <div class="search-card">
+                <h2>Newest Updated AS</h2>
+                {{ with .NewestAS }}
+                <p><a href="/as/{{ .ASN }}">AS{{ .ASN }}</a> {{ .Handle }}</p>
+                <p class="card-detail">{{ .Description }}</p>
+                <p class="card-time">Last seen {{ .LastSeen.UTC.Format "2006-01-02 15:04:05" }} UTC, {{ timeSince .LastSeen }}</p>
+                {{ else }}
+                <p>No AS has been seen yet.</p>
+                {{ end }}
+            </div>
+
+            <div class="search-card">
+                <h2>Oldest Updated AS</h2>
+                {{ with .OldestAS }}
+                <p><a href="/as/{{ .ASN }}">AS{{ .ASN }}</a> {{ .Handle }}</p>
+                <p class="card-detail">{{ .Description }}</p>
+                <p class="card-time">Last seen {{ .LastSeen.UTC.Format "2006-01-02 15:04:05" }} UTC, {{ timeSince .LastSeen }}</p>
+                {{ else }}
+                <p>No AS has been seen yet.</p>
+                {{ end }}
+            </div>
+
+            <div class="search-card">
+                <h2>AS with the Most Prefixes</h2>
+                {{ if .MostPrefixes }}
+                <p><a href="/as/{{ .MostPrefixesASN }}">AS{{ .MostPrefixesASN }}</a></p>
+                <p>Prefixes it originates: {{ .MostPrefixes }}</p>
+                {{ else }}
+                <p>No AS originates a prefix yet.</p>
+                {{ end }}
+            </div>
+
+            <div class="search-card">
+                <h2>ASes with the Fewest Prefixes</h2>
+                <p>ASes that originate a single prefix: {{ .SinglePrefixASes }}</p>
+                {{ with .NewestSinglePrefix }}
+                <p>The most recently updated of them: <a href="/as/{{ .OriginASN }}">AS{{ .OriginASN }}</a>, with <a href="{{ prefixURL .Prefix.String }}" class="prefix">{{ .Prefix }}</a></p>
+                <p class="card-time">{{ .Time.UTC.Format "2006-01-02 15:04:05" }} UTC, {{ timeSince .Time }}</p>
+                {{ end }}
+            </div>
+
+            <div class="search-card">
+                <h2>Bogon Announcements</h2>
+                <p class="card-figure"><a href="/bogons">{{ .BogonCount }}</a></p>
+                <p>Routes that announce a reserved prefix, or that come from a reserved AS number</p>
+            </div>
+
+            <div class="search-card">
+                <h2>Prefixes with Several Origins</h2>
+                <p class="card-figure"><a href="/multiple-origins">{{ .MultipleOriginCount }}</a></p>
+                <p>Prefixes announced by more than one origin AS</p>
+            </div>
+        </div>
+
+        <div class="search-card" id="well-known">
+            <h2>Well-Known Networks</h2>
+            <table>
+                <thead>
+                    <tr>
+                        <th>Network</th>
+                        <th>Prefixes</th>
+                        <th>Last Update</th>
+                    </tr>
+                </thead>
+                <tbody>
+                    {{ range .WellKnownNetworks }}
+                    <tr>
+                        <td><a href="/as/{{ .ASN }}">AS{{ .ASN }}</a> {{ .Name }}</td>
+                        <td>{{ .Prefixes }}</td>
+                        <td>{{ with .Newest }}{{ timeSince . }}{{ else }}no route{{ end }}</td>
+                    </tr>
+                    {{ end }}
+                </tbody>
+            </table>
+        </div>
+        {{ else }}
+        <div class="search-card" id="well-known">
+            <p>The figures of the routing table are being worked out. Reload the page in a minute.</p>
+        </div>
+        {{ end }}
+
         <div class="search-card" id="ip-api">
             <h2>IP Information API</h2>
             <p>The API answers what RouteWatch knows about an IP address, such as its AS number and country. <code>/ip/</code> with no address answers for the caller's own address.</p>
@@ -565,7 +714,8 @@
                 });
         });
 
-        // IP lookup
+        // IP lookup: show the whole JSON answer, its @meta and an error answer
+        // included, as the IP information API card does.
         document.getElementById('ip-form').addEventListener('submit', function(e) {
             e.preventDefault();
             const ip = document.getElementById('ip-input').value.trim();
@@ -581,18 +731,11 @@
 
             fetch('/ip/' + encodeURIComponent(ip))
                 .then(response => response.json())
-                .then(response => {
+                .then(answer => {
-                    contentEl.classList.remove('loading');
+                    contentEl.className = '';
-                    if (response.status === 'error') {
+                    contentEl.textContent = JSON.stringify(answer, null, 2);
-                        contentEl.className = 'error';
-                        contentEl.textContent = 'Error: ' + response.error.msg;
-                    } else {
-                        contentEl.className = '';
-                        contentEl.textContent = JSON.stringify(response.data, null, 2);
-                    }
                 })
                 .catch(error => {
-                    contentEl.classList.remove('loading');
                     contentEl.className = 'error';
                     contentEl.textContent = 'Error: ' + error.message;
                 });

internal/templates/multiple_origins.html

@@ -0,0 +1,182 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Prefixes with Several Origins - RouteWatch</title>
+    <style nonce="{{.CSPNonce}}">
+        * {
+            box-sizing: border-box;
+        }
+        body {
+            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
+            margin: 0;
+            padding: 0;
+            background: #f5f5f5;
+        }
+
+        /* Navbar styles */
+        .navbar {
+            background: #2c3e50;
+            padding: 0 20px;
+            display: flex;
+            align-items: center;
+            justify-content: space-between;
+            height: 56px;
+            box-shadow: 0 2px 4px rgba(0,0,0,0.1);
+        }
+        .navbar-brand {
+            display: flex;
+            align-items: center;
+            gap: 8px;
+            font-size: 18px;
+            font-weight: 600;
+        }
+        .navbar-brand a {
+            color: white;
+            text-decoration: none;
+        }
+        .navbar-brand a:hover {
+            color: #ecf0f1;
+        }
+        .navbar-brand .by {
+            font-weight: normal;
+            color: #95a5a6;
+            font-size: 14px;
+        }
+        .navbar-brand .author {
+            color: #3498db;
+            font-weight: normal;
+        }
+        .navbar-brand .author:hover {
+            text-decoration: underline;
+        }
+        .navbar-links {
+            display: flex;
+            gap: 20px;
+        }
+        .navbar-links a {
+            color: #ecf0f1;
+            text-decoration: none;
+            font-size: 14px;
+            padding: 8px 12px;
+            border-radius: 4px;
+            transition: background-color 0.2s;
+        }
+        .navbar-links a:hover {
+            background: rgba(255,255,255,0.1);
+        }
+
+        /* Main content */
+        .main-content {
+            max-width: 1200px;
+            margin: 0 auto;
+            padding: 20px;
+        }
+        h1 {
+            color: #333;
+            margin-bottom: 10px;
+        }
+        .subtitle {
+            color: #666;
+            margin-bottom: 30px;
+        }
+        table {
+            width: 100%;
+            border-collapse: collapse;
+            background: white;
+            box-shadow: 0 2px 4px rgba(0,0,0,0.1);
+            border-radius: 8px;
+            overflow: hidden;
+        }
+        th {
+            background: #f8f9fa;
+            padding: 12px;
+            text-align: left;
+            font-weight: 600;
+            color: #333;
+            border-bottom: 2px solid #dee2e6;
+        }
+        td {
+            padding: 12px;
+            border-bottom: 1px solid #eee;
+            vertical-align: top;
+        }
+        tr:last-child td {
+            border-bottom: none;
+        }
+        tr:hover {
+            background: #f8f9fa;
+        }
+        a {
+            color: #0066cc;
+            text-decoration: none;
+        }
+        a:hover {
+            text-decoration: underline;
+        }
+        .prefix-link {
+            font-family: 'SF Mono', Monaco, 'Cascadia Mono', 'Roboto Mono', Consolas, 'Courier New', monospace;
+        }
+        .origins {
+            list-style: none;
+            margin: 0;
+            padding: 0;
+        }
+        .peers {
+            color: #666;
+            font-size: 0.9em;
+        }
+    </style>
+</head>
+<body>
+    <nav class="navbar">
+        <div class="navbar-brand">
+            <a href="/">routewatch</a>
+            <span class="by">by</span>
+            <a href="https://sneak.berlin" class="author">@sneak</a>
+        </div>
+        <div class="navbar-links">
+            <a href="/">Home</a>
+            <a href="/status">Status</a>
+        </div>
+    </nav>
+
+    <main class="main-content">
+    <h1>Prefixes with Several Origin ASes</h1>
+    {{ with .Cards }}
+    <p class="subtitle">
+        Prefixes announced by more than one origin AS: {{ .MultipleOriginCount }}.
+        Such a prefix can be a hijack.
+        {{ if lt (len .MultipleOrigins) .MultipleOriginCount }}The first {{ len .MultipleOrigins }} are listed, in prefix order.{{ end }}
+        The list is worked out once a minute.
+    </p>
+
+    <table>
+        <thead>
+            <tr>
+                <th>Prefix</th>
+                <th>Origin ASes</th>
+            </tr>
+        </thead>
+        <tbody>
+            {{ range .MultipleOrigins }}
+            <tr>
+                <td><a href="{{ prefixURL .Prefix.String }}" class="prefix-link">{{ .Prefix }}</a></td>
+                <td>
+                    <ul class="origins">
+                        {{ range .Origins }}
+                        <li>{{ if .ASN }}<a href="/as/{{ .ASN }}">AS{{ .ASN }}</a>{{ else }}No known origin{{ end }} <span class="peers">{{ .Peers }} {{ if eq .Peers 1 }}peer{{ else }}peers{{ end }}</span></li>
+                        {{ end }}
+                    </ul>
+                </td>
+            </tr>
+            {{ end }}
+        </tbody>
+    </table>
+    {{ else }}
+    <p class="subtitle">The list is being worked out. Reload the page in a minute.</p>
+    {{ end }}
+    </main>
+</body>
+</html>

internal/templates/status.html

@@ -401,6 +401,8 @@
         const REFRESH_PERIOD_MS = 2000;
         const STALE_AFTER_REFRESHES = 3;
         const MS_PER_SECOND = 1000;
+        const SECONDS_PER_MINUTE = 60;
+        const SECONDS_PER_HOUR = 3600;
         const SPINNER_FRAMES = ['⠋', '⠙', '⠹', '⠸', '⠼', '⠴', '⠦', '⠧', '⠇', '⠏'];
         const SPINNER_COLOURS = ['#e74c3c', '#e67e22', '#f1c40f', '#27ae60', '#3498db', '#9b59b6'];
 
@@ -443,7 +445,18 @@
         function formatNumber(num) {
             return num.toLocaleString();
         }
-        
+
+        // formatDuration writes a number of seconds in hours, minutes and
+        // seconds, such as "1h 18m 34s" or "18.2s", with at most one decimal.
+        function formatDuration(totalSeconds) {
+            const hours = Math.floor(totalSeconds / SECONDS_PER_HOUR);
+            const minutes = Math.floor(totalSeconds % SECONDS_PER_HOUR / SECONDS_PER_MINUTE);
+            const seconds = parseFloat((totalSeconds % SECONDS_PER_MINUTE).toFixed(1));
+            if (hours > 0) return hours + 'h ' + minutes + 'm ' + seconds + 's';
+            if (minutes > 0) return minutes + 'm ' + seconds + 's';
+            return seconds + 's';
+        }
+
         function formatProcessingTime(ms) {
             if (ms < 0.001) {
                 return (ms * 1000).toFixed(0) + ' µs';
@@ -619,11 +632,13 @@
                     noteMessageCount(data.total_messages);
 
                     // Update all metrics
-                    document.getElementById('uptime').textContent = data.uptime;
+                    document.getElementById('uptime').textContent = formatDuration(data.uptime_seconds);
                     document.getElementById('go_version').textContent = data.go_version;
                     document.getElementById('goroutines').textContent = formatNumber(data.goroutines);
-                    document.getElementById('memory_usage').textContent = data.memory_usage;
+                    document.getElementById('memory_usage').textContent = formatBytes(data.memory_usage_bytes);
-                    document.getElementById('connection_duration').textContent = data.connection_duration;
+                    // connection_duration_seconds is null while the stream is not connected.
+                    document.getElementById('connection_duration').textContent =
+                        data.connection_duration_seconds === null ? 'disconnected' : formatDuration(data.connection_duration_seconds);
                     document.getElementById('reconnect_count').textContent = formatNumber(data.reconnect_count);
                     document.getElementById('total_messages').textContent = formatNumber(data.total_messages);
                     document.getElementById('messages_per_sec').textContent = formatNumber(Math.round(data.messages_per_sec));
@@ -672,7 +687,7 @@
                         const errorsEl = document.getElementById('whois_errors');
                         errorsEl.textContent = formatNumber(data.whois_stats.errors_last_hour);
                         errorsEl.className = 'metric-value' + (data.whois_stats.errors_last_hour > 0 ? ' disconnected' : '');
-                        document.getElementById('whois_interval').textContent = data.whois_stats.current_interval;
+                        document.getElementById('whois_interval').textContent = formatDuration(data.whois_stats.current_interval_seconds);
                     }
 
                     // Update handler stats

internal/templates/templates.go

@@ -27,6 +27,12 @@ var prefixDetailHTML string
 //go:embed prefix_length.html
 var prefixLengthHTML string
 
+//go:embed bogons.html
+var bogonsHTML string
+
+//go:embed multiple_origins.html
+var multipleOriginsHTML string
+
 // Templates contains all parsed templates
 type Templates struct {
 	// Index is the template for the home page
@@ -39,6 +45,11 @@ type Templates struct {
 	PrefixDetail *template.Template
 	// PrefixLength is the template for displaying prefixes by length
 	PrefixLength *template.Template
+	// Bogons is the template of the page that lists the bogon announcements
+	Bogons *template.Template
+	// MultipleOrigins is the template of the page that lists the prefixes
+	// announced by more than one origin AS
+	MultipleOrigins *template.Template
 }
 
 var (
@@ -116,6 +127,18 @@ func initTemplates() {
 	if err != nil {
 		panic("failed to parse prefix length template: " + err.Error())
 	}
+
+	defaultTemplates.Bogons, err = template.New("bogons").
+		Funcs(funcs).Parse(bogonsHTML)
+	if err != nil {
+		panic("failed to parse bogons template: " + err.Error())
+	}
+
+	defaultTemplates.MultipleOrigins, err = template.New("multipleOrigins").
+		Funcs(funcs).Parse(multipleOriginsHTML)
+	if err != nil {
+		panic("failed to parse multiple origins template: " + err.Error())
+	}
 }
 
 // Get returns the singleton Templates instance
@@ -149,3 +172,14 @@ func PrefixDetailTemplate() *template.Template {
 func PrefixLengthTemplate() *template.Template {
 	return Get().PrefixLength
 }
+
+// BogonsTemplate returns the parsed template of the bogon announcements page
+func BogonsTemplate() *template.Template {
+	return Get().Bogons
+}
+
+// MultipleOriginsTemplate returns the parsed template of the page of prefixes
+// announced by more than one origin AS
+func MultipleOriginsTemplate() *template.Template {
+	return Get().MultipleOrigins
+}

internal/templates/templates_test.go

@@ -12,13 +12,17 @@ import (
 )
 
 // renderPage renders a page with the data every page needs, and the visitor's
-// address, which the home page also needs.
+// address and the routing table's cards, which the home page also needs. The
+// cards are left out, as before the server first works them out.
 func renderPage(t *testing.T, tmpl *template.Template) string {
 	t.Helper()
 
 	var page bytes.Buffer
 
-	err := tmpl.Execute(&page, struct{ CSPNonce, ClientIP string }{})
+	err := tmpl.Execute(&page, struct {
+		CSPNonce, ClientIP string
+		Cards              any
+	}{})
 	if err != nil {
 		t.Fatalf("rendering the page: %v", err)
 	}