ASN is short for Autonomous System Number. It is a bit like the main phone number of a global company. It is a number which is globally unique and defines the path to the owner’s network, no matter whether it is a small network or a global player.
As a rule, one ASN is all you need for global operations – there is no need to own and operate multiple ASNs. Most of the big global networks operate a single-AS strategy.
ASNs and the BGB protocol
The ASN is used as a main parameter for what is known as the BGP protocol. The ASN is a key element of the process of BGP route advertisement. BGP takes care of advertising or receiving IPv4 or IPv6 networks, and the ASN information is used to help routers understand how to reach which route. The source ASN where an IP prefix is located is called the “originating ASN”.
Where and how to get an ASN
Download the white paper to learn more about
who hands out ASNs
what are RIRs and LIRs
the three main advantages of having your own ASN
Find out about the disadvantages of single-homing and the advantages of multi-homing.