Technical Summary
This document updates RFC 4271 and proscribes the use of Autonomous
System (AS) 0 in the Border Gateway Protocol (BGP) OPEN and AS_PATH /
AS4_PATH BGP attribute. This is important since although it has long
been understood that zero is not a valid AS number, this restriction has
never been formally specified.
Working Group Summary
There was active discussion in the WG and the document passed through
a number of iterations reflecting that. In the end the document
although short reflects a surprising amount of tuning.
Document Quality
There are at least two known BGP implementations that do not
accept AS number 0 in an AS_PATH as specified in the draft.
(Indeed, this appears to have been accepted implementation practice
prior to the draft's publication.)
Personnel
John Scudder is the Document Shepherd.
Stewart Bryant is the Responsible Area Director.
RFC Editor Note
OLD:
3. IANA Considerations
The IANA is requested to update the Reference for number 0 in the
"Autonomous System (AS) Numbers" registry to reference this document.
NEW:
3. IANA Considerations
The IANA is requested to update the registry for 16-bit Autonomous
System Numbers so that the entry for AS 0 is simply Reserved.
END