AS-SET Validator

Expand AS-SET objects from IRR databases. View member ASNs and generate IPv4/IPv6 prefix lists for BGP filter validation.

This tool is provided as a best-effort diagnostic aid. Results should be verified at the authoritative source before acting on them. This check runs from our infrastructure and may log queried information to improve accuracy and availability. Logs are retained for a short period and are not used for marketing.

Try:

What is an AS-SET?

An AS-SET is an object registered in an Internet Routing Registry (IRR) that groups together one or more AS numbers and other AS-SETs. Transit providers use AS-SETs to automatically build prefix filters for their customers, ensuring only authorised routes are accepted over BGP sessions.

For Network Operators

Register your AS-SET in an IRR database (APNIC, RIPE, RADB, etc.) and ensure your route/route6 objects are up to date. Your transit provider uses this to build the prefix filters on your BGP session.

For Transit Providers

Use this tool to verify a customer's AS-SET is properly registered and contains the expected member ASNs and prefixes before provisioning or updating BGP filters.

Related Tools

RPKI ValidatorCheck ROA coverage for prefixesLooking GlassRun BGP lookups and traceroutesWHOIS LookupCheck ASN and IP registration detailsSubnet CalculatorCalculate CIDR notation and IP ranges

How This Tool Works

This tool uses bgpq4 to query IRR databases and expand AS-SET objects into their member ASNs and corresponding IPv4/IPv6 prefix lists. It queries the same data sources that transit providers use to build BGP prefix filters, so you can verify your IRR registrations match what you expect before requesting a BGP session update.