BGP Tools

AS-SET Expander

Resolve a routing registry AS-SET recursively and list the member ASNs seen in RIPE DB.

Best for RIPE objects such as AS-RIPENCC, AS-HURRICANE, or ASxxxx:AS-CUSTOMERS.

AS-SET Expander

Recursively expand AS-SET macros from IRR data sources.

Category
routing
Tags
as-set, irr, bgp

Inputs

  • An AS-SET macro (e.g. AS-EXAMPLE)
  • Optional source filter (RADb, RIPE, etc.)

Outputs

  • Flat list of member ASNs
  • Optional flat list of associated prefixes
  • Resolution depth and any cycles encountered

Use Cases

  • Building a prefix-list for a new customer or peer
  • Auditing what an upstream's AS-SET actually contains
  • Diffing an AS-SET over time to catch surprise additions

Data Sources

  • IRR (RADb / RIPE / others)

Limitations

  • Quality of output depends on IRR data hygiene
  • Very large AS-SETs may take noticeable time to fully expand