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IRR Route Filter Generator

disabled

This tool generates router prefix-list / AS-path filter configurations. It's a config-generator for network operators, not an interactive query, so it's disabled in the public version.

This tool is registered in the catalog so you can see what's planned, but the runtime is disabled in the public version.

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Frequently Asked Questions

What is an IRR and why does it matter?

The Internet Routing Registry (IRR) is a distributed database where network operators publish their routing policies — which IP prefixes they originate and which ASNs they transit. Tools like bgpq4 query the IRR to generate prefix-lists and AS-path filters that routers use to accept only legitimate routes from peers, preventing route leaks and hijacks.

What is a BGP route leak and how do filters prevent it?

A route leak occurs when an AS re-advertises routes it shouldn't — typically a customer that re-announces its upstream's full table to another upstream, causing unexpected traffic flows. IRR-generated prefix-lists and AS-path filters on peering sessions ensure each peer only sends the routes they're authorized to originate, limiting the blast radius of misconfigurations.

What is the difference between bgpq3 and bgpq4?

bgpq4 is the successor to bgpq3, with IPv6 RPKI support, better IRR server handling, and JSON output. It queries IRR databases (RADB, RIPE, ARIN) for AS-SET and route objects, then generates filter configs in Cisco, Juniper, BIRD, or OpenBGPD syntax. Most operators have migrated to bgpq4 for new deployments.