Autonomous System Number (ASN)

An Autonomous System Number (ASN) is a unique number that's available globally to identify an autonomous system and which enables that system to exchange exterior routing information with other neighboring autonomous systems.

The number of autonomous system numbers is limited. For autonomous system numbers to be assigned, current guidelines need the network to be multi-homed and have a unique routing policy. Autonomous system numbers can be assigned only through a request to the local Internet registry.

In the early days ASN where limited to 2 Bytes. Public numbers range from 1 to 64511. Numbers above 64511 until 65534 are reserved for private use. Because this limitation the ASN has been expanded to 4 bytes. The old private range is preserved and a second private range is 4200000000 to 4294967294.

The public ASN for FFRL is 201701.

FFRL uses private ASN for the Autonomous Systems of the local communities.

The private ASN for Freifunk communities are used for connecting to the FFRL backbone wihich is documented in GitHub ICVPN-Meta.

At the time of writing I had not found any hint where and how to allocate an private ASN in FFRL.