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Distributed Prefix Assignment Algorithm

Approval announcement
Draft of message to be sent after approval:


From: The IESG <>
To: IETF-Announce <>
Cc: RFC Editor <>,
    homenet mailing list <>,
    homenet chair <>
Subject: Protocol Action: 'Distributed Prefix Assignment Algorithm' to Proposed Standard (draft-ietf-homenet-prefix-assignment-08.txt)

The IESG has approved the following document:
- 'Distributed Prefix Assignment Algorithm'
  (draft-ietf-homenet-prefix-assignment-08.txt) as Proposed Standard

This document is the product of the Home Networking Working Group.

The IESG contact persons are Brian Haberman and Terry Manderson.

A URL of this Internet Draft is:

Ballot Text

Technical Summary

This document specifies a distributed algorithm for prefix assignment within a site. While developed primarily for IPv6, it is generic enough to be used for any prefix-based numbering space such as IPv4. In order to run, the algorithm requires that participating nodes share information through a flooding mechanism of some kind.  If the flooding mechanism ensures that all messages are propagated to all nodes faster than a given timing upper bound, the algorithm also ensures that all assigned prefixes used for networking operations (e.g., host configuration) remain unchanged, unless another node assigns an overlapping prefix with a higher assignment priority, or the topology changes and renumbering cannot be avoided.

Working Group Summary

This algorithm began as an extension to OSPF as, at the time, the Homenet WG was heading down the path of using OSPF as a monolithic home network routing and configuration protocol. There was strong consensus against using OSPF in this manner in the WG, leading to the the standalone prefix-assignment document. As a modular piece of work, the algorithm has now been applied to OSPF, IS-IS, and HNCP.

RFC 7503 includes this text:

   “This new LSA is designated for information related to OSPFv3
   autoconfiguration and, in the future, could be used for other
   autoconfiguration information, e.g., global IPv6 prefixes.  However,
   this is beyond the scope of this document.”

While this document is not referenced directly above, the work in this document is what was in mind when RFC 7503 was written.

Document Quality

Open source implementation:, 


 Mark Townsley is the document shepherd
 Terry Manderson is the responsible AD

RFC Editor Note