BGP private AS numbers

Private BGP Autonomous System Numbers (ASNs) are a reserved range of AS numbers used for internal or private communication within an organization or between interconnected networks that are not meant to be globally advertised on the public internet. They allow organizations to set up BGP routing between their internal Autonomous Systems without consuming globally unique ASNs.

The Internet Assigned Numbers Authority (IANA) reserves the following ranges of ASNs for private use:

  1. 16-bit ASNs (RFC 6996): - Range: 64512 to 65534
  2. 32-bit ASNs (RFC 7300): - Range: 4200000000 to 4294967294

These ranges are intended solely for private use and are not meant to be used in the global internet routing table.

https://networklessons.com/bgp/bgp-private-and-public-as-range

https://datatracker.ietf.org/doc/html/rfc6996

https://datatracker.ietf.org/doc/html/rfc7300