ASN Cache

🇺🇸 English | 🇷🇺 Русский

Lightweight self-hosted ASN prefix cache and aggregation service.

Supported data sources:

• RIPEstat
• RouteViews
• RADB

Designed for use with Bird4Static, BIRD Internet Routing Daemon, and other route automation systems.

Features

• ASN → Prefix caching

• Multiple data sources:

  • RIPEstat
  • RouteViews
  • RADB

• Automatic aggregation of results from all available sources

• RIPEstat-compatible API

• Local SQLite storage

• Docker deployment support

• Low resource consumption

• Supports thousands of ASN records

• Can serve multiple routers from a single central instance

Architecture

Routers
    |
    v
ASN Cache API
    |
    +-- SQLite
    |
    +-- RIPEstat
    +-- RouteViews
    +-- RADB

Routers communicate only with the ASN Cache API.

The service automatically retrieves data from external sources and stores it locally.

Supported API

Get announced prefixes for an ASN

GET /data/announced-prefixes/data.json?resource=AS15169

Example response:

{
  "status": "ok",
  "data": {
    "resource": "AS15169",
    "prefixes": [
      {
        "prefix": "8.8.8.0/24"
      },
      {
        "prefix": "8.34.208.0/20"
      }
    ]
  }
}

Health check

GET /health

Response:

{
  "status": "ok"
}

Using ASN Cache with Bird4Static

Bird4Static normally queries RIPEstat directly:

curl https://stat.ripe.net/data/announced-prefixes/data.json?resource=AS15169

After deploying ASN Cache, simply replace the base URL:

curl https://asn-cache.example.com/data/announced-prefixes/data.json?resource=AS15169

No additional changes are required in the existing scripts.

Docker Deployment

Build:

docker compose build

Start:

docker compose up -d

Verify:

curl http://127.0.0.1:8080/health

Requirements

Docker

• Docker Engine
• Docker Compose Plugin

Native Installation

• Python 3.11+
• FastAPI
• Uvicorn
• SQLite

Security

It is recommended to restrict API access by IP address using a firewall or reverse proxy.

Example iptables configuration:

iptables -A INPUT -p tcp -s <ROUTER_IP_1> --dport 8080 -j ACCEPT
iptables -A INPUT -p tcp -s <ROUTER_IP_2> --dport 8080 -j ACCEPT
iptables -A INPUT -p tcp --dport 8080 -j DROP

Performance

Typical database sizes:

ASN Count	Database Size
500	< 5 MB
2,000	10–20 MB
10,000	50–100 MB

The service is suitable for low-resource VPS instances.

Typical Use Case

• Deploy ASN Cache on a central VPS.
• Multiple routers use it as an ASN → Prefix source.
• The service reduces load on RIPEstat and other public services.
• Cached data remains available even if one of the upstream providers becomes temporarily unavailable.

Bird4Static Integration

This project was originally designed to work with Bird4Static.

Reference implementation:

• Bird4Static func.sh

See the examples below for integrating ASN Cache as a custom ASN prefix source.

Add a new function to func.sh

#GET PREFIXES FROM PERSONAL FUNCTION
get_prefixes_personal_func() {
  local cur_as="$1"
  local result

  result="$(
    retry_cmd_func "personal" "$cur_as" \
      curl -fsSk "http://YOUR_DOMAIN_OR_IP/data/announced-prefixes/data.json?resource=$cur_as" |
      jq -r '.data.prefixes[]? | select(.prefix? and (.prefix | contains("."))) | .prefix'
  )"

  log_source_result_func "personal" "$cur_as" "$result"
  printf '%s\n' "$result"
}

Modify the get_as_func() function

Locate the following section:

result="$(get_prefixes_ripe_func "$cur_as")"
[[ -z "$result" ]] && result="$(get_prefixes_routeviews_func "$cur_as")"
[[ -z "$result" ]] && result="$(get_prefixes_radb_func "$cur_as")"

Replace it with:

result="$(get_prefixes_personal_func "$cur_as")"
[[ -z "$result" ]] && result="$(get_prefixes_ripe_func "$cur_as")"
[[ -z "$result" ]] && result="$(get_prefixes_routeviews_func "$cur_as")"
[[ -z "$result" ]] && result="$(get_prefixes_radb_func "$cur_as")"

With this change, Bird4Static will first query ASN Cache. If the service is unavailable or returns no data, the script will automatically fall back to RIPEstat, RouteViews, and RADB.

Documentation

Document	Description
Nginx Reverse Proxy Configuration	Publishing ASN Cache via HTTP/HTTPS

Using HTTPS

If ASN Cache is published through Nginx with TLS enabled:

curl -fsSk "https://asn-cache.example.com/data/announced-prefixes/data.json?resource=$cur_as"

Roadmap

Planned features:

• Background ASN refresh scheduler
• IPv6 support
• Source attribution for prefixes
• Metrics and statistics endpoint
• Web-based ASN explorer
• PostgreSQL backend support
• Prefix change history

License

MIT License