# BGP 4-Byte AS Number - Asplain notation

BGP uses AS numbers as a fundamental part of its routing process. Because conventional 2-byte public AS numbers were becoming exhausted, the IANA increased the AS numbers by introducing a 4-byte AS numbers. The Asplain notation to represent these AS numbers is simply to use the decimal value that corresponds to the binary value.

4-Byte AS numbers, which use 32 bits to represent them in binary, range from 0 to 4294967295.

4-Byte AS numbers can also be represented using the Asdot notation as well as the Asdot+ notation.

Links:

https://networklessons.com/bgp/bgp-4-byte-number/

https://forum.networklessons.com/t/bgp-4-byte-as-number/3184/25?u=lagapides