Serve the /api/v1/stats prefix distribution from memory (closes #30)

The prefix distribution was the last query on the stats path. It read one
index entry per live route on every request, so on a large database it took
the whole 4-second deadline and /api/v1/stats answered 500.

The distribution now lives next to the in-memory counts: seeded once at
startup from the same query, then kept exact by every live-route write. A new
route whose prefix had no live route adds one at its mask length; a delete
that leaves a prefix with no live route takes one away. Each check is one
lookup on the prefix index, made only for new and removed routes, within the
same write. The single-route delete now runs its delete and that lookup in one
transaction, so a failed lookup cannot leave the counts off.

Model: opus-5-5

README.md

@@ -142,10 +142,7 @@ routewatch/
 - **Backpressure**: Probabilistic message dropping when queues exceed 50% capacity
 - **Graceful Shutdown**: 60-second timeout, flushes all pending batches
 - **Reconnection**: Exponential backoff (5s-320s) with reset after 30s of stable connection
-- **IP Lookup**: the most specific live route is found by looking up the
-  address's prefix at each mask length, longest first, in the prefix index
-  (at most 33 lookups for IPv4, 129 for IPv6); prefixes are stored in the
-  text form Go's `net/netip` prints
+- **IPv4 Optimization**: IP ranges stored as uint32 for O(1) lookups
 
 ### Database Schema
 
@@ -157,7 +154,7 @@ prefixes_v6(id, prefix, mask_length, first_seen, last_seen)
 
 -- Live routing tables (one per IP version)
 live_routes_v4(id, prefix, mask_length, origin_asn, peer_ip, as_path,
-               next_hop, last_updated)
+               next_hop, last_updated, v4_ip_start, v4_ip_end)
 live_routes_v6(id, prefix, mask_length, origin_asn, peer_ip, as_path,
                next_hop, last_updated)
 

TODO.md

@@ -30,16 +30,6 @@ real 5 GiB limit (https://git.eeqj.de/sneak/routewatch/issues/3).
 - 2026-10-03: `/api/v1/stats` serves the prefix distribution from memory,
   seeded at startup and adjusted on every live-route write, so a request no
   longer reads every live route (closes #30)
-- 2026-10-03: a new database is created with `auto_vacuum` set to
-  incremental, through the connection string so it is set before the file
-  is first written, and each periodic incremental vacuum now returns up to
-  1000 free pages; the late `PRAGMA auto_vacuum` in `Initialize`, which
-  SQLite ignored, is gone (closes #43)
-- 2026-10-03: looking up an IP address no longer reads every IPv6 route:
-  both families find the most specific live route with at most 33 or 129
-  lookups on the prefix index, and the IPv4 range columns are gone. Prefixes
-  from the feed are stored in one text form, so an IPv6 withdrawal, which the
-  feed sends uncompressed, now removes its route (closes #48)
 - 2026-10-02: a plain `docker build .` stamps the commit's tag or short
   commit (`git describe --tags --always`) into the page footer instead of
   `unknown`: `.dockerignore` sends `.git` without `.git/config`, a `VERSION`

internal/database/counts_test.go

@@ -12,11 +12,15 @@ import (
 	"github.com/google/uuid"
 )
 
-// mkV4Route builds an IPv4 live route with its mask length taken from the
-// prefix.
+// mkV4Route builds an IPv4 live route with its mask length and range columns
+// taken from the prefix.
 func mkV4Route(t *testing.T, prefix string, asn int, ts time.Time) *LiveRoute {
 	t.Helper()
 
+	start, end, err := CalculateIPv4Range(prefix)
+	if err != nil {
+		t.Fatalf("CalculateIPv4Range(%s): %v", prefix, err)
+	}
 	maskLength, err := prefixMaskLength(prefix)
 	if err != nil {
 		t.Fatalf("prefixMaskLength(%s): %v", prefix, err)
@@ -32,6 +36,8 @@ func mkV4Route(t *testing.T, prefix string, asn int, ts time.Time) *LiveRoute {
 		ASPath:      []int{asn},
 		NextHop:     "192.0.2.254",
 		LastUpdated: ts,
+		V4IPStart:   &start,
+		V4IPEnd:     &end,
 	}
 }
 
@@ -203,8 +209,6 @@ func TestPrefixDistributionTracksWrites(t *testing.T) {
 	other := mkV4Route(t, "203.0.113.0/24", 64501, ts)
 	wide := mkV4Route(t, "172.16.0.0/16", 64502, ts)
 	v6 := mkV6Route("2001:db8::/32", 64503, ts)
-	v6SecondPeer := mkV6Route("2001:db8::/32", 64503, ts)
-	v6SecondPeer.PeerIP = "2001:db8::2"
 
 	all := []PrefixDistribution{{MaskLength: 16, Count: 1}, {MaskLength: 24, Count: 2}}
 	v6Only := []PrefixDistribution{{MaskLength: 32, Count: 1}}
@@ -228,46 +232,32 @@ func TestPrefixDistributionTracksWrites(t *testing.T) {
 		},
 		{
 			name:     "second peer announces a prefix that has a live route",
-			announce: []*LiveRoute{sharedSecondPeer, v6SecondPeer},
+			announce: []*LiveRoute{sharedSecondPeer},
 			wantV4:   all, wantV6: v6Only,
 		},
 		{
 			name:     "withdrawal of a route that is not the last for its prefix",
-			withdraw: []*LiveRoute{shared, v6},
+			withdraw: []*LiveRoute{shared},
 			wantV4:   all, wantV6: v6Only,
 		},
 		{
 			name:     "withdrawal of the last route for a prefix",
-			withdraw: []*LiveRoute{sharedSecondPeer, v6SecondPeer},
+			withdraw: []*LiveRoute{sharedSecondPeer},
 			wantV4:   []PrefixDistribution{{MaskLength: 16, Count: 1}, {MaskLength: 24, Count: 1}},
+			wantV6:   v6Only,
 		},
 		{
 			name:     "withdrawal of every remaining route",
-			withdraw: []*LiveRoute{other, wide},
+			withdraw: []*LiveRoute{other, wide, v6},
 		},
 		{
 			name:     "two peers announce a new prefix together",
-			announce: []*LiveRoute{shared, sharedSecondPeer, v6, v6SecondPeer},
+			announce: []*LiveRoute{shared, sharedSecondPeer},
 			wantV4:   []PrefixDistribution{{MaskLength: 24, Count: 1}},
-			wantV6:   v6Only,
 		},
 		{
 			name:     "both routes for a prefix withdrawn together",
-			withdraw: []*LiveRoute{shared, sharedSecondPeer, v6, v6SecondPeer},
-		},
-		// The feed often withdraws a route that is not live. That must not take
-		// the prefix out of the distribution. A count wrongly taken below zero is
-		// left out of the answer, so the next step shows it: its announcement
-		// at the same mask length would then not be counted.
-		{
-			name:     "withdrawal of routes that are not live",
-			withdraw: []*LiveRoute{other, v6},
-		},
-		{
-			name:     "announcement after a withdrawal of routes that are not live",
-			announce: []*LiveRoute{other, v6},
-			wantV4:   []PrefixDistribution{{MaskLength: 24, Count: 1}},
-			wantV6:   v6Only,
+			withdraw: []*LiveRoute{shared, sharedSecondPeer},
 		},
 	}
 

internal/database/database.go

@@ -9,7 +9,6 @@ import (
 	"errors"
 	"fmt"
 	"net"
-	"net/netip"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -33,8 +32,11 @@ const (
 	dirPermissions = 0750 // rwxr-x---
 	ipVersionV4    = 4
 	ipVersionV6    = 6
+	ipv6Length     = 16
+	ipv4Offset     = 12
 	ipv4Bits       = 32
 	ipv6Bits       = 128
+	maxIPv4        = 0xFFFFFFFF
 )
 
 // SQLite memory tuning. cache_size and busy_timeout go in the DSN so every
@@ -93,13 +95,8 @@ func New(cfg *config.Config, logger *logger.Logger) (*Database, error) {
 	// a transaction that reads before writing starts as a reader and, when it
 	// then writes while another connection holds the write lock, fails at once
 	// with "database is locked" without waiting for _busy_timeout.
-	// _auto_vacuum=incremental lets Vacuum return free pages to the filesystem.
-	// SQLite only accepts it before the database file is first written, and the
-	// switch to WAL writes it, so it must be here: the driver applies it on open,
-	// before _journal_mode. On an existing file it changes nothing.
 	dsn := fmt.Sprintf(
-		"file:%s?_cache_size=%d&_synchronous=OFF&_busy_timeout=%d"+
-			"&_auto_vacuum=incremental&_journal_mode=WAL&_txlock=immediate",
+		"file:%s?_cache_size=%d&_synchronous=OFF&_busy_timeout=%d&_journal_mode=WAL&_txlock=immediate",
 		dbPath,
 		sqliteCacheSizeKiB,
 		sqliteBusyTimeoutMs,
@@ -144,8 +141,9 @@ func (d *Database) Initialize() error {
 	// heap. The heap limits below are process-wide, so setting them once here is
 	// enough for the whole pool.
 	pragmas := []string{
-		"PRAGMA journal_mode=WAL", // Write-Ahead Logging
-		"PRAGMA analysis_limit=0", // Disable automatic ANALYZE
+		"PRAGMA journal_mode=WAL",        // Write-Ahead Logging
+		"PRAGMA analysis_limit=0",        // Disable automatic ANALYZE
+		"PRAGMA auto_vacuum=INCREMENTAL", // Enable incremental vacuum
 		fmt.Sprintf("PRAGMA soft_heap_limit=%d", sqliteSoftHeapLimitBytes),
 		fmt.Sprintf("PRAGMA hard_heap_limit=%d", sqliteHardHeapLimitBytes),
 	}
@@ -228,10 +226,10 @@ func (d *Database) beginTx() (*loggingTx, error) {
 // upsert did.
 const (
 	updateLiveRouteV4SQL = `UPDATE live_routes_v4 SET mask_length = ?, as_path = ?, next_hop = ?,
-		last_updated = ? WHERE prefix = ? AND origin_asn = ? AND peer_ip = ?`
+		last_updated = ?, ip_start = ?, ip_end = ? WHERE prefix = ? AND origin_asn = ? AND peer_ip = ?`
 
 	insertLiveRouteV4SQL = `INSERT INTO live_routes_v4 (id, prefix, mask_length, origin_asn, peer_ip,
-		as_path, next_hop, last_updated) VALUES (?, ?, ?, ?, ?, ?, ?, ?)`
+		as_path, next_hop, last_updated, ip_start, ip_end) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`
 
 	updateLiveRouteV6SQL = `UPDATE live_routes_v6 SET mask_length = ?, as_path = ?, next_hop = ?,
 		last_updated = ? WHERE prefix = ? AND origin_asn = ? AND peer_ip = ?`
@@ -253,8 +251,12 @@ const (
 // live route for its prefix.
 func upsertRouteRowV4(upd, ins, has *sql.Stmt, route *LiveRoute, pathJSON string) (
 	inserted, newPrefix bool, err error) {
+	if route.V4IPStart == nil || route.V4IPEnd == nil {
+		return false, false, fmt.Errorf("IPv4 route %s missing range values", route.Prefix)
+	}
+
 	res, err := upd.Exec(route.MaskLength, pathJSON, route.NextHop, route.LastUpdated,
-		route.Prefix, route.OriginASN, route.PeerIP)
+		*route.V4IPStart, *route.V4IPEnd, route.Prefix, route.OriginASN, route.PeerIP)
 	if err != nil {
 		return false, false, err
 	}
@@ -272,7 +274,7 @@ func upsertRouteRowV4(upd, ins, has *sql.Stmt, route *LiveRoute, pathJSON string
 	}
 
 	_, err = ins.Exec(route.ID.String(), route.Prefix, route.MaskLength, route.OriginASN,
-		route.PeerIP, pathJSON, route.NextHop, route.LastUpdated)
+		route.PeerIP, pathJSON, route.NextHop, route.LastUpdated, *route.V4IPStart, *route.V4IPEnd)
 	if err != nil {
 		return false, false, err
 	}
@@ -1395,10 +1397,6 @@ func (d *Database) GetPrefixDistributionContext(ctx context.Context) (
 		}
 		ipv4 = append(ipv4, dist)
 	}
-	// A read that stops partway ends the loop without an error of its own.
-	if err := rows4.Err(); err != nil {
-		return nil, nil, fmt.Errorf("failed to read IPv4 distribution: %w", err)
-	}
 
 	// IPv6 distribution - count unique prefixes from v6 table
 	query = `
@@ -1424,9 +1422,6 @@ func (d *Database) GetPrefixDistributionContext(ctx context.Context) (
 		}
 		ipv6 = append(ipv6, dist)
 	}
-	if err := rows6.Err(); err != nil {
-		return nil, nil, fmt.Errorf("failed to read IPv6 distribution: %w", err)
-	}
 
 	return ipv4, ipv6, nil
 }
@@ -1453,6 +1448,176 @@ func (d *Database) GetLiveRouteCountsContext(ctx context.Context) (ipv4Count, ip
 	return ipv4Count, ipv6Count, nil
 }
 
+// GetASInfoForIP returns AS information for the given IP address
+func (d *Database) GetASInfoForIP(ip string) (*ASInfo, error) {
+	return d.GetASInfoForIPContext(context.Background(), ip)
+}
+
+// GetASInfoForIPContext returns AS information for the given IP address with context support
+func (d *Database) GetASInfoForIPContext(ctx context.Context, ip string) (*ASInfo, error) {
+	// Parse the IP to validate it
+	parsedIP := net.ParseIP(ip)
+	if parsedIP == nil {
+		return nil, fmt.Errorf("%w: %s", ErrInvalidIP, ip)
+	}
+
+	// Determine IP version
+	ipVersion := ipVersionV4
+	ipv4 := parsedIP.To4()
+	if ipv4 == nil {
+		ipVersion = ipVersionV6
+	}
+
+	// For IPv4, use optimized range query
+	if ipVersion == ipVersionV4 {
+		// Convert IP to 32-bit unsigned integer
+		ipUint := ipToUint32(ipv4)
+
+		query := `
+			SELECT DISTINCT lr.prefix, lr.mask_length, lr.origin_asn, lr.last_updated, a.handle, a.description
+			FROM live_routes_v4 lr
+			LEFT JOIN asns a ON a.asn = lr.origin_asn
+			WHERE lr.ip_start <= ? AND lr.ip_end >= ?
+			ORDER BY lr.mask_length DESC
+			LIMIT 1
+		`
+
+		var prefix string
+		var maskLength, originASN int
+		var lastUpdated time.Time
+		var handle, description sql.NullString
+
+		err := d.db.QueryRowContext(ctx, query, ipUint, ipUint).Scan(
+			&prefix, &maskLength, &originASN, &lastUpdated, &handle, &description)
+		if err != nil {
+			if err == sql.ErrNoRows {
+				return nil, fmt.Errorf("%w for IP %s", ErrNoRoute, ip)
+			}
+
+			return nil, fmt.Errorf("failed to query routes: %w", err)
+		}
+
+		age := time.Since(lastUpdated).Round(time.Second).String()
+
+		return &ASInfo{
+			ASN:         originASN,
+			Handle:      handle.String,
+			Description: description.String,
+			Prefix:      prefix,
+			LastUpdated: lastUpdated,
+			Age:         age,
+		}, nil
+	}
+
+	// For IPv6, use the original method since we don't have range optimization
+	query := `
+		SELECT DISTINCT lr.prefix, lr.mask_length, lr.origin_asn, lr.last_updated, a.handle, a.description
+		FROM live_routes_v6 lr
+		LEFT JOIN asns a ON a.asn = lr.origin_asn
+		ORDER BY lr.mask_length DESC
+	`
+
+	rows, err := d.db.QueryContext(ctx, query)
+	if err != nil {
+		return nil, fmt.Errorf("failed to query routes: %w", err)
+	}
+	defer func() { _ = rows.Close() }()
+
+	// Find the most specific matching prefix
+	var bestMatch struct {
+		prefix      string
+		maskLength  int
+		originASN   int
+		lastUpdated time.Time
+		handle      sql.NullString
+		description sql.NullString
+	}
+	bestMaskLength := -1
+
+	for rows.Next() {
+		var prefix string
+		var maskLength, originASN int
+		var lastUpdated time.Time
+		var handle, description sql.NullString
+
+		if err := rows.Scan(&prefix, &maskLength, &originASN, &lastUpdated, &handle, &description); err != nil {
+			continue
+		}
+
+		// Parse the prefix CIDR
+		_, ipNet, err := net.ParseCIDR(prefix)
+		if err != nil {
+			continue
+		}
+
+		// Check if the IP is in this prefix
+		if ipNet.Contains(parsedIP) && maskLength > bestMaskLength {
+			bestMatch.prefix = prefix
+			bestMatch.maskLength = maskLength
+			bestMatch.originASN = originASN
+			bestMatch.lastUpdated = lastUpdated
+			bestMatch.handle = handle
+			bestMatch.description = description
+			bestMaskLength = maskLength
+		}
+	}
+
+	if bestMaskLength == -1 {
+		return nil, fmt.Errorf("%w for IP %s", ErrNoRoute, ip)
+	}
+
+	age := time.Since(bestMatch.lastUpdated).Round(time.Second).String()
+
+	return &ASInfo{
+		ASN:         bestMatch.originASN,
+		Handle:      bestMatch.handle.String,
+		Description: bestMatch.description.String,
+		Prefix:      bestMatch.prefix,
+		LastUpdated: bestMatch.lastUpdated,
+		Age:         age,
+	}, nil
+}
+
+// ipToUint32 converts an IPv4 address to a 32-bit unsigned integer
+func ipToUint32(ip net.IP) uint32 {
+	if len(ip) == ipv6Length {
+		// Convert to 4-byte representation
+		ip = ip[ipv4Offset:ipv6Length]
+	}
+
+	return uint32(ip[0])<<24 | uint32(ip[1])<<16 | uint32(ip[2])<<8 | uint32(ip[3])
+}
+
+// CalculateIPv4Range calculates the start and end IP addresses for an IPv4 CIDR block
+func CalculateIPv4Range(cidr string) (start, end uint32, err error) {
+	_, ipNet, err := net.ParseCIDR(cidr)
+	if err != nil {
+		return 0, 0, err
+	}
+
+	// Get the network address (start of range)
+	ip := ipNet.IP.To4()
+	if ip == nil {
+		return 0, 0, fmt.Errorf("not an IPv4 address")
+	}
+
+	start = ipToUint32(ip)
+
+	// Calculate the end of the range
+	ones, bits := ipNet.Mask.Size()
+	hostBits := bits - ones
+	if hostBits >= ipv4Bits {
+		// Special case for /0 - entire IPv4 space
+		end = maxIPv4
+	} else {
+		// Safe to convert since we checked hostBits < 32
+		//nolint:gosec // hostBits is guaranteed to be < 32 from the check above
+		end = start | ((1 << uint(hostBits)) - 1)
+	}
+
+	return start, end, nil
+}
+
 // GetASDetails returns detailed information about an AS including prefixes
 func (d *Database) GetASDetails(asn int) (*ASN, []LiveRoute, error) {
 	return d.GetASDetailsContext(context.Background(), asn)
@@ -1874,37 +2039,39 @@ func (d *Database) GetIPInfo(ip string) (*IPInfo, error) {
 }
 
 // GetIPInfoContext returns comprehensive IP information with context support.
-//
-// It finds the most specific live route for the address with point lookups on
-// the prefix index: for each mask length from the longest (32 or 128) down to 0
-// it looks up the address's network prefix at that length, and the first length
-// with a live route wins. That is at most 33 or 129 indexed lookups, however
-// many routes are live. The prefix is looked up in the text form net/netip
-// prints, which is the form the prefix handler stores.
 func (d *Database) GetIPInfoContext(ctx context.Context, ip string) (*IPInfo, error) {
-	addr, err := netip.ParseAddr(ip)
-	if err != nil {
+	// Parse the IP to validate it
+	parsedIP := net.ParseIP(ip)
+	if parsedIP == nil {
 		return nil, fmt.Errorf("%w: %s", ErrInvalidIP, ip)
 	}
-	// An IPv4 address written in IPv6 form (::ffff:192.0.2.1) is an IPv4 lookup.
-	addr = addr.Unmap()
 
-	info := &IPInfo{IP: ip, IPVersion: ipVersionV6}
-	routesTable, prefixesTable := "live_routes_v6", "prefixes_v6"
-	if addr.Is4() {
-		info.IPVersion = ipVersionV4
-		routesTable, prefixesTable = "live_routes_v4", "prefixes_v4"
+	// Determine IP version
+	ipv4 := parsedIP.To4()
+	if ipv4 != nil {
+		return d.getIPv4Info(ctx, ip, ipv4)
 	}
 
-	// Route info with peer count and prefix first_seen
-	//nolint:gosec // Table names are hardcoded based on IP version
-	query := fmt.Sprintf(`
+	return d.getIPv6Info(ctx, ip, parsedIP)
+}
+
+// getIPv4Info returns comprehensive IP information for an IPv4 address.
+func (d *Database) getIPv4Info(ctx context.Context, ip string, ipv4 net.IP) (*IPInfo, error) {
+	info := &IPInfo{
+		IP:        ip,
+		IPVersion: ipVersionV4,
+	}
+
+	ipUint := ipToUint32(ipv4)
+
+	// Get route info with peer count and prefix first_seen
+	query := `
 		SELECT
 			lr.prefix,
 			lr.mask_length,
 			lr.origin_asn,
 			lr.last_updated,
-			(SELECT COUNT(DISTINCT peer_ip) FROM %[1]s WHERE prefix = lr.prefix) as num_peers,
+			(SELECT COUNT(DISTINCT peer_ip) FROM live_routes_v4 WHERE prefix = lr.prefix) as num_peers,
 			p.first_seen,
 			a.handle,
 			a.description,
@@ -1916,56 +2083,42 @@ func (d *Database) GetIPInfoContext(ctx context.Context, ip string) (*IPInfo, er
 			a.abuse_email,
 			a.rir,
 			a.whois_updated_at
-		FROM %[1]s lr
-		LEFT JOIN %[2]s p ON p.prefix = lr.prefix
+		FROM live_routes_v4 lr
+		LEFT JOIN prefixes_v4 p ON p.prefix = lr.prefix
 		LEFT JOIN asns a ON a.asn = lr.origin_asn
-		WHERE lr.prefix = ?
+		WHERE lr.ip_start <= ? AND lr.ip_end >= ?
+		ORDER BY lr.mask_length DESC
 		LIMIT 1
-	`, routesTable, prefixesTable)
-
-	stmt, err := d.db.PrepareContext(ctx, query)
-	if err != nil {
-		return nil, fmt.Errorf("failed to prepare route query: %w", err)
-	}
-	defer func() { _ = stmt.Close() }()
+	`
 
 	var handle, description, asName, orgName, orgID, address, countryCode, abuseEmail, rir sql.NullString
 	var prefixFirstSeen sql.NullTime
 	var whoisUpdatedAt sql.NullTime
 
-	found := false
-	for bits := addr.BitLen(); bits >= 0; bits-- {
-		prefix := netip.PrefixFrom(addr, bits).Masked().String()
-		err := stmt.QueryRowContext(ctx, prefix).Scan(
-			&info.Netblock,
-			&info.MaskLength,
-			&info.ASN,
-			&info.LastSeen,
-			&info.NumPeers,
-			&prefixFirstSeen,
-			&handle,
-			&description,
-			&asName,
-			&orgName,
-			&orgID,
-			&address,
-			&countryCode,
-			&abuseEmail,
-			&rir,
-			&whoisUpdatedAt,
-		)
-		if errors.Is(err, sql.ErrNoRows) {
-			continue
+	err := d.db.QueryRowContext(ctx, query, ipUint, ipUint).Scan(
+		&info.Netblock,
+		&info.MaskLength,
+		&info.ASN,
+		&info.LastSeen,
+		&info.NumPeers,
+		&prefixFirstSeen,
+		&handle,
+		&description,
+		&asName,
+		&orgName,
+		&orgID,
+		&address,
+		&countryCode,
+		&abuseEmail,
+		&rir,
+		&whoisUpdatedAt,
+	)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return nil, fmt.Errorf("%w for IP %s", ErrNoRoute, ip)
 		}
-		if err != nil {
-			return nil, fmt.Errorf("failed to query routes: %w", err)
-		}
-		found = true
 
-		break
-	}
-	if !found {
-		return nil, fmt.Errorf("%w for IP %s", ErrNoRoute, ip)
+		return nil, fmt.Errorf("failed to query routes: %w", err)
 	}
 
 	info.Handle = handle.String
@@ -1989,26 +2142,116 @@ func (d *Database) GetIPInfoContext(ctx context.Context, ip string) (*IPInfo, er
 	return info, nil
 }
 
+// getIPv6Info returns comprehensive IP information for an IPv6 address.
+func (d *Database) getIPv6Info(ctx context.Context, ip string, parsedIP net.IP) (*IPInfo, error) {
+	info := &IPInfo{
+		IP:        ip,
+		IPVersion: ipVersionV6,
+	}
+
+	// For IPv6, scan all routes and find best match
+	query := `
+		SELECT DISTINCT
+			lr.prefix,
+			lr.mask_length,
+			lr.origin_asn,
+			lr.last_updated,
+			a.handle,
+			a.description,
+			a.as_name,
+			a.org_name,
+			a.org_id,
+			a.address,
+			a.country_code,
+			a.abuse_email,
+			a.rir,
+			a.whois_updated_at
+		FROM live_routes_v6 lr
+		LEFT JOIN asns a ON a.asn = lr.origin_asn
+		ORDER BY lr.mask_length DESC
+	`
+
+	rows, err := d.db.QueryContext(ctx, query)
+	if err != nil {
+		return nil, fmt.Errorf("failed to query routes: %w", err)
+	}
+	defer func() { _ = rows.Close() }()
+
+	bestMaskLength := -1
+
+	for rows.Next() {
+		var prefix string
+		var maskLength, originASN int
+		var lastUpdated time.Time
+		var handle, description, asName, orgName, orgID, address, countryCode, abuseEmail, rir sql.NullString
+		var whoisUpdatedAt sql.NullTime
+
+		if err := rows.Scan(
+			&prefix, &maskLength, &originASN, &lastUpdated,
+			&handle, &description, &asName, &orgName, &orgID,
+			&address, &countryCode, &abuseEmail, &rir, &whoisUpdatedAt,
+		); err != nil {
+			continue
+		}
+
+		_, ipNet, err := net.ParseCIDR(prefix)
+		if err != nil {
+			continue
+		}
+
+		if ipNet.Contains(parsedIP) && maskLength > bestMaskLength {
+			info.Netblock = prefix
+			info.MaskLength = maskLength
+			info.ASN = originASN
+			info.LastSeen = lastUpdated
+			info.Handle = handle.String
+			info.Description = description.String
+			info.ASName = asName.String
+			info.OrgName = orgName.String
+			info.OrgID = orgID.String
+			info.Address = address.String
+			info.CountryCode = countryCode.String
+			info.AbuseEmail = abuseEmail.String
+			info.RIR = rir.String
+			bestMaskLength = maskLength
+
+			if !whoisUpdatedAt.Valid {
+				info.NeedsWHOISRefresh = true
+			} else {
+				const staleThreshold = 30 * 24 * time.Hour
+				info.NeedsWHOISRefresh = time.Since(whoisUpdatedAt.Time) > staleThreshold
+			}
+		}
+	}
+
+	if bestMaskLength == -1 {
+		return nil, fmt.Errorf("%w for IP %s", ErrNoRoute, ip)
+	}
+
+	// Get peer count and first_seen for IPv6
+	countQuery := `SELECT COUNT(DISTINCT peer_ip) FROM live_routes_v6 WHERE prefix = ?`
+	_ = d.db.QueryRowContext(ctx, countQuery, info.Netblock).Scan(&info.NumPeers)
+
+	firstSeenQuery := `SELECT first_seen FROM prefixes_v6 WHERE prefix = ?`
+	var prefixFirstSeen sql.NullTime
+	err = d.db.QueryRowContext(ctx, firstSeenQuery, info.Netblock).Scan(&prefixFirstSeen)
+	if err == nil && prefixFirstSeen.Valid {
+		info.FirstSeen = prefixFirstSeen.Time
+	}
+
+	return info, nil
+}
+
 // Vacuum runs incremental vacuum to reclaim unused pages without blocking writes.
 // It frees up to the specified number of pages per call (0 = all freeable pages).
 func (d *Database) Vacuum(ctx context.Context) error {
 	// Free up to 1000 pages per call (~4MB with default 4KB page size)
 	// This keeps each vacuum operation quick and non-blocking
 	const pagesToFree = 1000
-	rows, err := d.db.QueryContext(ctx, fmt.Sprintf("PRAGMA incremental_vacuum(%d)", pagesToFree))
+	_, err := d.db.ExecContext(ctx, fmt.Sprintf("PRAGMA incremental_vacuum(%d)", pagesToFree))
 	if err != nil {
 		return fmt.Errorf("failed to run incremental vacuum: %w", err)
 	}
-	defer func() { _ = rows.Close() }()
-
-	// SQLite frees one page each time the statement steps, and each step
-	// returns a row, so every row must be read for the pragma to free more
-	// than one page.
-	for rows.Next() {
-	}
-	if err := rows.Err(); err != nil {
-		return fmt.Errorf("failed to run incremental vacuum: %w", err)
-	}
 
 	return nil
 }

internal/database/database_test.go

@@ -3,36 +3,23 @@ package database
 import (
 	"context"
 	"database/sql"
-	"errors"
-	"fmt"
-	"net/netip"
+	"net"
 	"sync"
 	"testing"
 	"time"
 
 	"git.eeqj.de/sneak/routewatch/internal/config"
 	"git.eeqj.de/sneak/routewatch/internal/logger"
-	"github.com/google/uuid"
 )
 
 // tempStoreMemory is the PRAGMA temp_store value meaning "hold temp B-trees in
 // memory"; the DSN change must leave temp_store below this so they spill to disk.
 const tempStoreMemory = 2
 
-// autoVacuumIncremental is the PRAGMA auto_vacuum value meaning "incremental".
-const autoVacuumIncremental = 2
-
-// vacuumTestRoutes is how many routes the vacuum test writes and then deletes,
-// enough to leave many free pages in the file.
-const vacuumTestRoutes = 2000
-
 // heldConnections is how many pooled connections the pragma test holds open at
 // once so each is a distinct SQLite connection that parsed the DSN.
 const heldConnections = 5
 
-// testPeerIP is the peer every route in the IP lookup test is learned from.
-const testPeerIP = "192.0.2.254"
-
 // Parameters for the checkpoint-contention regression test.
 const (
 	// contentionIterations is how many batch writes race the checkpoint loop.
@@ -45,98 +32,286 @@ const (
 	asnSecondBand = 100
 )
 
-// TestGetIPInfoFindsMostSpecificLiveRoute stores nested live prefixes for both
-// families and checks that a lookup returns the most specific one covering the
-// address, ErrNoRoute when none covers it, and the next less specific prefix
-// once the only route of the most specific one is withdrawn.
-func TestGetIPInfoFindsMostSpecificLiveRoute(t *testing.T) {
-	cfg := &config.Config{StateDir: t.TempDir()}
-
-	db, err := New(cfg, logger.New())
-	if err != nil {
-		t.Fatalf("failed to create database: %v", err)
-	}
-	defer func() { _ = db.Close() }()
-
-	// Nested live prefixes, each originated by its own AS.
-	origins := map[string]int{
-		"10.0.0.0/8":        64500,
-		"10.1.0.0/16":       64501,
-		"10.1.2.0/24":       64502,
-		"2001:db8::/32":     64500,
-		"2001:db8:1::/48":   64501,
-		"2001:db8:1:2::/64": 64502,
-	}
-	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
-	routes := make([]*LiveRoute, 0, len(origins))
-	for prefix, asn := range origins {
-		routes = append(routes, &LiveRoute{
-			ID:          uuid.New(),
-			Prefix:      prefix,
-			MaskLength:  netip.MustParsePrefix(prefix).Bits(),
-			IPVersion:   detectIPVersion(prefix),
-			OriginASN:   asn,
-			PeerIP:      testPeerIP,
-			ASPath:      []int{asn},
-			NextHop:     testPeerIP,
-			LastUpdated: ts,
-		})
-	}
-	if err := db.UpsertLiveRouteBatch(routes); err != nil {
-		t.Fatalf("UpsertLiveRouteBatch: %v", err)
+func TestIPToUint32(t *testing.T) {
+	tests := []struct {
+		name     string
+		ip       string
+		expected uint32
+	}{
+		{
+			name:     "Simple IP",
+			ip:       "192.168.1.1",
+			expected: 3232235777, // 192<<24 + 168<<16 + 1<<8 + 1
+		},
+		{
+			name:     "Minimum IP",
+			ip:       "0.0.0.0",
+			expected: 0,
+		},
+		{
+			name:     "Maximum IP",
+			ip:       "255.255.255.255",
+			expected: 4294967295,
+		},
+		{
+			name:     "10.0.0.0",
+			ip:       "10.0.0.0",
+			expected: 167772160,
+		},
+		{
+			name:     "172.16.0.0",
+			ip:       "172.16.0.0",
+			expected: 2886729728,
+		},
+		{
+			name:     "8.8.8.8",
+			ip:       "8.8.8.8",
+			expected: 134744072,
+		},
+		{
+			name:     "1.2.3.4",
+			ip:       "1.2.3.4",
+			expected: 16909060,
+		},
 	}
 
-	// lookup checks that ip resolves to the live prefix want, or to ErrNoRoute
-	// when want is empty.
-	lookup := func(ip, want string) {
-		t.Helper()
-
-		info, err := db.GetIPInfo(ip)
-		if want == "" {
-			if !errors.Is(err, ErrNoRoute) {
-				t.Errorf("GetIPInfo(%s) = %+v, %v; want ErrNoRoute", ip, info, err)
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ip := net.ParseIP(tt.ip)
+			if ip == nil {
+				t.Fatalf("Failed to parse IP: %s", tt.ip)
 			}
 
-			return
-		}
-		if err != nil {
-			t.Errorf("GetIPInfo(%s): %v", ip, err)
+			result := ipToUint32(ip)
+			if result != tt.expected {
+				t.Errorf("ipToUint32(%s) = %d, want %d", tt.ip, result, tt.expected)
+			}
 
-			return
-		}
-		if info.Netblock != want || info.MaskLength != netip.MustParsePrefix(want).Bits() ||
-			info.ASN != origins[want] {
-			t.Errorf("GetIPInfo(%s) = %s (mask %d) AS%d, want %s AS%d",
-				ip, info.Netblock, info.MaskLength, info.ASN, want, origins[want])
-		}
+			// Test with IPv4-mapped IPv6 address
+			ip6 := net.ParseIP(tt.ip).To16()
+			if ip6 != nil {
+				result6 := ipToUint32(ip6)
+				if result6 != tt.expected {
+					t.Errorf("ipToUint32(%s as IPv6) = %d, want %d", tt.ip, result6, tt.expected)
+				}
+			}
+		})
+	}
+}
+
+func TestCalculateIPv4Range(t *testing.T) {
+	tests := []struct {
+		name      string
+		cidr      string
+		wantStart uint32
+		wantEnd   uint32
+		wantErr   bool
+	}{
+		{
+			name:      "Single IP /32",
+			cidr:      "192.168.1.1/32",
+			wantStart: 3232235777,
+			wantEnd:   3232235777,
+		},
+		{
+			name:      "Class C /24",
+			cidr:      "192.168.1.0/24",
+			wantStart: 3232235776, // 192.168.1.0
+			wantEnd:   3232236031, // 192.168.1.255
+		},
+		{
+			name:      "Class B /16",
+			cidr:      "192.168.0.0/16",
+			wantStart: 3232235520, // 192.168.0.0
+			wantEnd:   3232301055, // 192.168.255.255
+		},
+		{
+			name:      "Class A /8",
+			cidr:      "10.0.0.0/8",
+			wantStart: 167772160, // 10.0.0.0
+			wantEnd:   184549375, // 10.255.255.255
+		},
+		{
+			name:      "Entire IPv4 space /0",
+			cidr:      "0.0.0.0/0",
+			wantStart: 0,
+			wantEnd:   4294967295,
+		},
+		{
+			name:      "Small subnet /30",
+			cidr:      "192.168.1.0/30",
+			wantStart: 3232235776, // 192.168.1.0
+			wantEnd:   3232235779, // 192.168.1.3
+		},
+		{
+			name:      "Medium subnet /20",
+			cidr:      "172.16.0.0/20",
+			wantStart: 2886729728, // 172.16.0.0
+			wantEnd:   2886733823, // 172.16.15.255
+		},
+		{
+			name:      "Private range 172.16/12",
+			cidr:      "172.16.0.0/12",
+			wantStart: 2886729728, // 172.16.0.0
+			wantEnd:   2887778303, // 172.31.255.255
+		},
+		{
+			name:      "Google DNS /29",
+			cidr:      "8.8.8.8/29",
+			wantStart: 134744072, // 8.8.8.8 (network is actually 8.8.8.8 with /29)
+			wantEnd:   134744079, // 8.8.8.15
+		},
+		{
+			name:      "Non-zero host bits",
+			cidr:      "192.168.1.5/24",
+			wantStart: 3232235776, // 192.168.1.0 (network address)
+			wantEnd:   3232236031, // 192.168.1.255
+		},
+		{
+			name:    "Invalid CIDR",
+			cidr:    "192.168.1.1/33",
+			wantErr: true,
+		},
+		{
+			name:    "Invalid IP",
+			cidr:    "256.256.256.256/24",
+			wantErr: true,
+		},
+		{
+			name:    "IPv6 CIDR",
+			cidr:    "2001:db8::/32",
+			wantErr: true,
+		},
+		{
+			name:    "Empty CIDR",
+			cidr:    "",
+			wantErr: true,
+		},
+		{
+			name:    "Missing mask",
+			cidr:    "192.168.1.1",
+			wantErr: true,
+		},
 	}
 
-	lookup("10.1.2.3", "10.1.2.0/24")
-	lookup("::ffff:10.1.2.3", "10.1.2.0/24")
-	lookup("10.1.3.4", "10.1.0.0/16")
-	lookup("10.2.0.1", "10.0.0.0/8")
-	lookup("192.0.2.1", "")
-	lookup("2001:db8:1:2::3", "2001:db8:1:2::/64")
-	lookup("2001:db8:1:3::4", "2001:db8:1::/48")
-	lookup("2001:db8:2::1", "2001:db8::/32")
-	lookup("2001:db9::1", "")
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			start, end, err := CalculateIPv4Range(tt.cidr)
 
-	err = db.DeleteLiveRouteBatch([]LiveRouteDeletion{
-		{Prefix: "10.1.2.0/24", OriginASN: 64502, PeerIP: testPeerIP, IPVersion: ipVersionV4},
-		{Prefix: "2001:db8:1:2::/64", OriginASN: 64502, PeerIP: testPeerIP, IPVersion: ipVersionV6},
-	})
-	if err != nil {
-		t.Fatalf("DeleteLiveRouteBatch: %v", err)
+			if tt.wantErr {
+				if err == nil {
+					t.Errorf("CalculateIPv4Range(%s) expected error, got nil", tt.cidr)
+				}
+				return
+			}
+
+			if err != nil {
+				t.Errorf("CalculateIPv4Range(%s) unexpected error: %v", tt.cidr, err)
+				return
+			}
+
+			if start != tt.wantStart {
+				t.Errorf("CalculateIPv4Range(%s) start = %d, want %d", tt.cidr, start, tt.wantStart)
+			}
+
+			if end != tt.wantEnd {
+				t.Errorf("CalculateIPv4Range(%s) end = %d, want %d", tt.cidr, end, tt.wantEnd)
+			}
+
+			// Verify that start <= end
+			if start > end {
+				t.Errorf("CalculateIPv4Range(%s) start (%d) > end (%d)", tt.cidr, start, end)
+			}
+
+			// Verify the range size matches the CIDR mask
+			if !tt.wantErr && tt.cidr != "" {
+				_, ipNet, _ := net.ParseCIDR(tt.cidr)
+				if ipNet != nil {
+					ones, bits := ipNet.Mask.Size()
+					expectedSize := uint32(1) << uint(bits-ones)
+					actualSize := end - start + 1
+					if actualSize != expectedSize {
+						t.Errorf("CalculateIPv4Range(%s) range size = %d, want %d", tt.cidr, actualSize, expectedSize)
+					}
+				}
+			}
+		})
+	}
+}
+
+func TestIPv4RangeIntegration(t *testing.T) {
+	// Test that our functions work correctly together
+	tests := []struct {
+		name          string
+		cidr          string
+		testIPs       []string
+		shouldContain []bool
+	}{
+		{
+			name: "192.168.1.0/24",
+			cidr: "192.168.1.0/24",
+			testIPs: []string{
+				"192.168.1.0",
+				"192.168.1.1",
+				"192.168.1.255",
+				"192.168.0.255",
+				"192.168.2.0",
+			},
+			shouldContain: []bool{true, true, true, false, false},
+		},
+		{
+			name: "10.0.0.0/8",
+			cidr: "10.0.0.0/8",
+			testIPs: []string{
+				"10.0.0.0",
+				"10.255.255.255",
+				"10.1.2.3",
+				"9.255.255.255",
+				"11.0.0.0",
+			},
+			shouldContain: []bool{true, true, true, false, false},
+		},
+		{
+			name: "172.16.0.0/12",
+			cidr: "172.16.0.0/12",
+			testIPs: []string{
+				"172.16.0.0",
+				"172.31.255.255",
+				"172.20.1.1",
+				"172.15.255.255",
+				"172.32.0.0",
+			},
+			shouldContain: []bool{true, true, true, false, false},
+		},
 	}
 
-	lookup("10.1.2.3", "10.1.0.0/16")
-	lookup("2001:db8:1:2::3", "2001:db8:1::/48")
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			start, end, err := CalculateIPv4Range(tt.cidr)
+			if err != nil {
+				t.Fatalf("Failed to calculate range for %s: %v", tt.cidr, err)
+			}
+
+			for i, testIP := range tt.testIPs {
+				ip := net.ParseIP(testIP)
+				if ip == nil {
+					t.Fatalf("Failed to parse test IP: %s", testIP)
+				}
+
+				ipUint := ipToUint32(ip)
+				contained := ipUint >= start && ipUint <= end
+
+				if contained != tt.shouldContain[i] {
+					t.Errorf("IP %s in range %s: got %v, want %v", testIP, tt.cidr, contained, tt.shouldContain[i])
+				}
+			}
+		})
+	}
 }
 
 // TestConnectionPoolPragmas holds several pooled connections open at once and
 // checks each one carries the per-connection settings from the DSN, plus the
-// process-wide hard heap limit, and sees the new file with auto_vacuum
-// incremental.
+// process-wide hard heap limit.
 func TestConnectionPoolPragmas(t *testing.T) {
 	cfg := &config.Config{StateDir: t.TempDir()}
 
@@ -197,74 +372,6 @@ func TestConnectionPoolPragmas(t *testing.T) {
 		if hardHeapLimit != sqliteHardHeapLimitBytes {
 			t.Errorf("conn %d: hard_heap_limit = %d, want %d", i, hardHeapLimit, sqliteHardHeapLimitBytes)
 		}
-
-		var autoVacuum int
-		if err := c.QueryRowContext(ctx, "PRAGMA auto_vacuum").Scan(&autoVacuum); err != nil {
-			t.Fatalf("conn %d: failed to read auto_vacuum: %v", i, err)
-		}
-		if autoVacuum != autoVacuumIncremental {
-			t.Errorf("conn %d: auto_vacuum = %d, want %d (incremental)", i, autoVacuum, autoVacuumIncremental)
-		}
-	}
-}
-
-// TestVacuumReturnsFreePages checks that after routes are deleted from a new
-// database, one Vacuum call returns every page they used. The deletes leave
-// fewer free pages than the 1000 Vacuum frees per call, so none may remain.
-// With auto_vacuum off (issue https://git.eeqj.de/sneak/routewatch/issues/43)
-// the free pages stayed in the file, and with the PRAGMA run by ExecContext
-// Vacuum freed only one page per call.
-func TestVacuumReturnsFreePages(t *testing.T) {
-	cfg := &config.Config{StateDir: t.TempDir()}
-
-	db, err := New(cfg, logger.New())
-	if err != nil {
-		t.Fatalf("failed to create database: %v", err)
-	}
-	defer func() { _ = db.Close() }()
-
-	ctx := context.Background()
-	ts := time.Now().UTC()
-	const asn = 64500
-
-	routes := make([]*LiveRoute, 0, vacuumTestRoutes)
-	deletions := make([]LiveRouteDeletion, 0, vacuumTestRoutes)
-	for i := range vacuumTestRoutes {
-		route := mkV4Route(t, fmt.Sprintf("10.%d.%d.0/24", i/256, i%256), asn, ts)
-		routes = append(routes, route)
-		deletions = append(deletions, LiveRouteDeletion{
-			Prefix:    route.Prefix,
-			OriginASN: asn,
-			PeerIP:    route.PeerIP,
-			IPVersion: ipVersionV4,
-		})
-	}
-
-	if err := db.UpsertLiveRouteBatch(routes); err != nil {
-		t.Fatalf("failed to write routes: %v", err)
-	}
-	if err := db.DeleteLiveRouteBatch(deletions); err != nil {
-		t.Fatalf("failed to delete routes: %v", err)
-	}
-
-	var before int
-	if err := db.db.QueryRowContext(ctx, "PRAGMA freelist_count").Scan(&before); err != nil {
-		t.Fatalf("failed to read freelist_count: %v", err)
-	}
-	if before == 0 {
-		t.Fatalf("no free pages after deleting %d routes", vacuumTestRoutes)
-	}
-
-	if err := db.Vacuum(ctx); err != nil {
-		t.Fatalf("Vacuum failed: %v", err)
-	}
-
-	var after int
-	if err := db.db.QueryRowContext(ctx, "PRAGMA freelist_count").Scan(&after); err != nil {
-		t.Fatalf("failed to read freelist_count: %v", err)
-	}
-	if after != 0 {
-		t.Errorf("free pages after Vacuum = %d of %d, want 0", after, before)
 	}
 }
 
@@ -317,3 +424,21 @@ func TestBatchWriteDuringCheckpoint(t *testing.T) {
 	cancel()
 	wg.Wait()
 }
+
+func BenchmarkIPToUint32(b *testing.B) {
+	ip := net.ParseIP("192.168.1.1")
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		_ = ipToUint32(ip)
+	}
+}
+
+func BenchmarkCalculateIPv4Range(b *testing.B) {
+	cidr := "192.168.0.0/16"
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		_, _, _ = CalculateIPv4Range(cidr)
+	}
+}

internal/database/interface.go

@@ -63,6 +63,8 @@ type Store interface {
 	GetLiveRouteCountsContext(ctx context.Context) (ipv4Count, ipv6Count int, err error)
 
 	// IP lookup operations
+	GetASInfoForIP(ip string) (*ASInfo, error)
+	GetASInfoForIPContext(ctx context.Context, ip string) (*ASInfo, error)
 	GetIPInfo(ip string) (*IPInfo, error)
 	GetIPInfoContext(ctx context.Context, ip string) (*IPInfo, error)
 

internal/database/models.go

@@ -77,6 +77,9 @@ type LiveRoute struct {
 	ASPath      []int     `json:"as_path"`
 	NextHop     string    `json:"next_hop"`
 	LastUpdated time.Time `json:"last_updated"`
+	// IPv4 range fields for fast lookups (nil for IPv6)
+	V4IPStart *uint32 `json:"v4_ip_start,omitempty"`
+	V4IPEnd   *uint32 `json:"v4_ip_end,omitempty"`
 }
 
 // PrefixDistribution represents the distribution of prefixes by mask length
@@ -85,6 +88,16 @@ type PrefixDistribution struct {
 	Count      int `json:"count"`
 }
 
+// ASInfo represents AS information for an IP lookup (legacy format)
+type ASInfo struct {
+	ASN         int       `json:"asn"`
+	Handle      string    `json:"handle"`
+	Description string    `json:"description"`
+	Prefix      string    `json:"prefix"`
+	LastUpdated time.Time `json:"last_updated"`
+	Age         string    `json:"age"`
+}
+
 // IPInfo represents comprehensive IP information for the /ip endpoint
 type IPInfo struct {
 	IP         string   `json:"ip"`

internal/database/schema.sql

@@ -107,6 +107,9 @@ CREATE TABLE IF NOT EXISTS live_routes_v4 (
 	as_path TEXT NOT NULL, -- JSON array
 	next_hop TEXT NOT NULL,
 	last_updated DATETIME NOT NULL,
+	-- IPv4 range columns for fast lookups
+	ip_start INTEGER NOT NULL, -- Start of IPv4 range as 32-bit unsigned int
+	ip_end INTEGER NOT NULL,    -- End of IPv4 range as 32-bit unsigned int
 	UNIQUE(prefix, origin_asn, peer_ip)
 );
 
@@ -120,6 +123,7 @@ CREATE TABLE IF NOT EXISTS live_routes_v6 (
 	as_path TEXT NOT NULL, -- JSON array
 	next_hop TEXT NOT NULL,
 	last_updated DATETIME NOT NULL,
+	-- Note: IPv6 doesn't use integer range columns
 	UNIQUE(prefix, origin_asn, peer_ip)
 );
 
@@ -128,6 +132,8 @@ CREATE INDEX IF NOT EXISTS idx_live_routes_v4_prefix ON live_routes_v4(prefix);
 CREATE INDEX IF NOT EXISTS idx_live_routes_v4_mask_length ON live_routes_v4(mask_length);
 CREATE INDEX IF NOT EXISTS idx_live_routes_v4_origin_asn ON live_routes_v4(origin_asn);
 CREATE INDEX IF NOT EXISTS idx_live_routes_v4_last_updated ON live_routes_v4(last_updated);
+-- Indexes for IPv4 range queries
+CREATE INDEX IF NOT EXISTS idx_live_routes_v4_ip_range ON live_routes_v4(ip_start, ip_end);
 -- Index to optimize prefix distribution queries
 CREATE INDEX IF NOT EXISTS idx_live_routes_v4_mask_prefix ON live_routes_v4(mask_length, prefix);
 

internal/routewatch/app_integration_test.go

@@ -232,6 +232,25 @@ func (m *mockStore) GetLiveRouteCountsContext(ctx context.Context) (ipv4Count, i
 	return m.GetLiveRouteCounts()
 }
 
+// GetASInfoForIP mock implementation
+func (m *mockStore) GetASInfoForIP(ip string) (*database.ASInfo, error) {
+	// Simple mock - return a test AS
+	now := time.Now()
+	return &database.ASInfo{
+		ASN:         15169,
+		Handle:      "GOOGLE",
+		Description: "Google LLC",
+		Prefix:      "8.8.8.0/24",
+		LastUpdated: now.Add(-5 * time.Minute),
+		Age:         "5m0s",
+	}, nil
+}
+
+// GetASInfoForIPContext mock implementation with context support
+func (m *mockStore) GetASInfoForIPContext(ctx context.Context, ip string) (*database.ASInfo, error) {
+	return m.GetASInfoForIP(ip)
+}
+
 // GetASDetails mock implementation
 func (m *mockStore) GetASDetails(asn int) (*database.ASN, []database.LiveRoute, error) {
 	m.mu.Lock()

internal/routewatch/prefixhandler.go

@@ -2,7 +2,6 @@ package routewatch
 
 import (
 	"net"
-	"net/netip"
 	"strings"
 	"sync"
 	"time"
@@ -109,7 +108,7 @@ func (h *PrefixHandler) HandleMessage(msg *ristypes.RISMessage) {
 	for _, announcement := range msg.Announcements {
 		for _, prefix := range announcement.Prefixes {
 			h.batch = append(h.batch, prefixUpdate{
-				prefix:      canonicalPrefix(prefix),
+				prefix:      prefix,
 				originASN:   originASN,
 				peer:        msg.Peer,
 				messageType: "announcement",
@@ -126,7 +125,7 @@ func (h *PrefixHandler) HandleMessage(msg *ristypes.RISMessage) {
 	// Process withdrawals
 	for _, prefix := range msg.Withdrawals {
 		h.batch = append(h.batch, prefixUpdate{
-			prefix:      canonicalPrefix(prefix),
+			prefix:      prefix,
 			originASN:   originASN, // Use the originASN from path if available
 			peer:        msg.Peer,
 			messageType: "withdrawal",
@@ -265,21 +264,6 @@ func (h *PrefixHandler) flushBatchLocked() {
 	h.lastFlush = time.Now()
 }
 
-// canonicalPrefix returns prefix in the text form net/netip prints, the form
-// the IP lookup builds when it looks a prefix up. The feed sends IPv6
-// announcements compressed ("2001:db8::/32") but IPv6 withdrawals uncompressed
-// ("2001:db8:0:0:0:0:0:0/32"); stored as received, a withdrawal would not match
-// the route its announcement stored. A prefix that does not parse is returned
-// unchanged, and the batch flush reports it.
-func canonicalPrefix(prefix string) string {
-	p, err := netip.ParsePrefix(prefix)
-	if err != nil {
-		return prefix
-	}
-
-	return p.Masked().String()
-}
-
 // parseCIDR extracts the mask length and IP version from a prefix string
 func parseCIDR(prefix string) (maskLength int, ipVersion int, err error) {
 	_, ipNet, err := net.ParseCIDR(prefix)
@@ -331,6 +315,20 @@ func (h *PrefixHandler) processAnnouncement(_ *database.Prefix, update prefixUpd
 		LastUpdated: update.timestamp,
 	}
 
+	// For IPv4, calculate the IP range
+	if ipVersion == ipv4Version {
+		start, end, err := database.CalculateIPv4Range(update.prefix)
+		if err == nil {
+			liveRoute.V4IPStart = &start
+			liveRoute.V4IPEnd = &end
+		} else {
+			h.logger.Error("Failed to calculate IPv4 range",
+				"prefix", update.prefix,
+				"error", err,
+			)
+		}
+	}
+
 	if err := h.db.UpsertLiveRoute(liveRoute); err != nil {
 		h.logger.Error("Failed to upsert live route",
 			"prefix", update.prefix,
@@ -374,6 +372,20 @@ func (h *PrefixHandler) createLiveRoute(update prefixUpdate) *database.LiveRoute
 		LastUpdated: update.timestamp,
 	}
 
+	// For IPv4, calculate the IP range
+	if ipVersion == ipv4Version {
+		start, end, err := database.CalculateIPv4Range(update.prefix)
+		if err == nil {
+			liveRoute.V4IPStart = &start
+			liveRoute.V4IPEnd = &end
+		} else {
+			h.logger.Error("Failed to calculate IPv4 range",
+				"prefix", update.prefix,
+				"error", err,
+			)
+		}
+	}
+
 	return liveRoute
 }
 
@@ -413,6 +425,20 @@ func (h *PrefixHandler) processAnnouncementDirect(update prefixUpdate) {
 		LastUpdated: update.timestamp,
 	}
 
+	// For IPv4, calculate the IP range
+	if ipVersion == ipv4Version {
+		start, end, err := database.CalculateIPv4Range(update.prefix)
+		if err == nil {
+			liveRoute.V4IPStart = &start
+			liveRoute.V4IPEnd = &end
+		} else {
+			h.logger.Error("Failed to calculate IPv4 range",
+				"prefix", update.prefix,
+				"error", err,
+			)
+		}
+	}
+
 	if err := h.db.UpsertLiveRoute(liveRoute); err != nil {
 		h.logger.Error("Failed to upsert live route",
 			"prefix", update.prefix,

internal/routewatch/prefixhandler_test.go

@@ -1,74 +0,0 @@
-package routewatch
-
-import (
-	"errors"
-	"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/ristypes"
-)
-
-const testPeerIP = "2001:db8:ffff::1"
-
-// TestPrefixHandlerStoresPrefixesTheIPLookupFinds runs announcements and
-// withdrawals through the prefix handler into a real database and looks the
-// addresses up. The prefixes are written the way the feed sends them: IPv6
-// announcements compressed, IPv6 withdrawals uncompressed. The withdrawal must
-// remove the route the announcement stored, and the IP lookup must find the
-// stored prefix.
-func TestPrefixHandlerStoresPrefixesTheIPLookupFinds(t *testing.T) {
-	db, err := database.New(&config.Config{StateDir: t.TempDir()}, logger.New())
-	if err != nil {
-		t.Fatalf("failed to create database: %v", err)
-	}
-	defer func() { _ = db.Close() }()
-
-	// Built without NewPrefixHandler's flush timer, so the test flushes itself.
-	h := &PrefixHandler{db: db, logger: logger.New()}
-	flush := func() {
-		h.mu.Lock()
-		defer h.mu.Unlock()
-		h.flushBatchLocked()
-	}
-
-	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
-	h.HandleMessage(&ristypes.RISMessage{
-		Peer:            testPeerIP,
-		Path:            ristypes.ASPath{testASNA, testASNB},
-		ParsedTimestamp: ts,
-		Announcements: []ristypes.RISAnnouncement{{
-			NextHop:  testPeerIP,
-			Prefixes: []string{"2001:db8:1::/48", "192.0.2.0/24"},
-		}},
-	})
-	flush()
-
-	for ip, want := range map[string]string{
-		"2001:db8:1::1": "2001:db8:1::/48",
-		"192.0.2.1":     "192.0.2.0/24",
-	} {
-		info, err := db.GetIPInfo(ip)
-		if err != nil {
-			t.Fatalf("GetIPInfo(%s) after announcement: %v", ip, err)
-		}
-		if info.Netblock != want || info.ASN != testASNB {
-			t.Errorf("GetIPInfo(%s) = %s AS%d, want %s AS%d", ip, info.Netblock, info.ASN, want, testASNB)
-		}
-	}
-
-	h.HandleMessage(&ristypes.RISMessage{
-		Peer:            testPeerIP,
-		ParsedTimestamp: ts.Add(time.Minute),
-		Withdrawals:     []string{"2001:db8:1:0:0:0:0:0/48", "192.0.2.0/24"},
-	})
-	flush()
-
-	for _, ip := range []string{"2001:db8:1::1", "192.0.2.1"} {
-		if info, err := db.GetIPInfo(ip); !errors.Is(err, database.ErrNoRoute) {
-			t.Errorf("GetIPInfo(%s) after withdrawal = %+v, %v; want ErrNoRoute", ip, info, err)
-		}
-	}
-}

internal/server/handlers_test.go

@@ -89,11 +89,15 @@ func TestStatsHandlersAnswerFromMemory(t *testing.T) {
 	}
 
 	ts := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
+	start, end, err := database.CalculateIPv4Range("198.51.100.0/24")
+	if err != nil {
+		t.Fatalf("CalculateIPv4Range: %v", err)
+	}
 	if err := db.UpsertLiveRouteBatch([]*database.LiveRoute{
 		{
 			ID: uuid.New(), Prefix: "198.51.100.0/24", MaskLength: 24, IPVersion: 4,
 			OriginASN: 64500, PeerIP: "192.0.2.1", ASPath: []int{64500}, NextHop: "192.0.2.1",
-			LastUpdated: ts,
+			LastUpdated: ts, V4IPStart: &start, V4IPEnd: &end,
 		},
 		{
 			ID: uuid.New(), Prefix: "2001:db8::/32", MaskLength: 32, IPVersion: 6,