Codification of AS 0 Processing
RFC 7607

Approval announcement
Draft of message to be sent after approval:

From: The IESG <>
To: IETF-Announce <>
Cc: RFC Editor <>,
    idr mailing list <>,
    idr chair <>
Subject: Protocol Action: 'Codification of AS 0 processing.' to Proposed Standard (draft-ietf-idr-as0-06.txt)

The IESG has approved the following document:
- 'Codification of AS 0 processing.'
  (draft-ietf-idr-as0-06.txt) as Proposed Standard

This document is the product of the Inter-Domain Routing Working Group.

The IESG contact persons are Stewart Bryant and Adrian Farrel.

A URL of this Internet Draft is:

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.) 


  John Scudder is the Document Shepherd.
  Stewart Bryant is the Responsible Area Director.

RFC Editor Note


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.


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.