Autonomous-System-Wide Unique BGP Identifier for BGP-4
E. Chen, Jinhong Yuan · 2011
To accommodate situations where the current requirements for the BGP Identifier are not met, this document relaxes the definition of the BGP Identifier to be a 4-octet unsigned, non-zero integer, and relaxes the requirement so that only AS-wide uniqueness of the BGP Identifiers is required. These revisions to the base BGP specification do not introduce any backward compatibility issue.