OSPF Graceful Link Shutdown

Approval announcement
Draft of message to be sent after approval:

From: The IESG <iesg-secretary@ietf.org>
To: IETF-Announce <ietf-announce@ietf.org>
Cc: The IESG <iesg@ietf.org>, draft-ietf-ospf-link-overload@ietf.org, akatlas@gmail.com, ospf@ietf.org, Acee Lindem <acee@cisco.com>, acee@cisco.com, ospf-chairs@ietf.org, rfc-editor@rfc-editor.org
Subject: Protocol Action: 'OSPF Graceful Link shutdown' to Proposed Standard (draft-ietf-ospf-link-overload-16.txt)

The IESG has approved the following document:
- 'OSPF Graceful Link shutdown'
  (draft-ietf-ospf-link-overload-16.txt) as Proposed Standard

This document is the product of the Open Shortest Path First IGP Working

The IESG contact persons are Alvaro Retana, Alia Atlas and Deborah Brungard.

A URL of this Internet Draft is:

Technical Summary

When a link is being prepared to be taken out of service, the traffic
   needs to be diverted from both ends of the link.  Increasing the
   metric to the highest value on one side of the link is not sufficient
   to divert the traffic flowing in the other direction.

   It is useful for routers in an OSPFv2 or OSPFv3 routing domain to be
   able to advertise a link as being in a graceful-shutdown state to
   indicate impending maintenance activity on the link.  This
   information can be used by the network devices to re-route the
   traffic effectively.

   This document describes the protocol extensions to disseminate
   graceful-link-shutdown information in OSPFv2 and OSPFv3.

Working Group Summary

There was considerable discussion on both the use case and whether
      we could use signaling amongst the routers on the link. However, 
      this would not allow a controller to be informed. Additionally,
      there was discussion as to whether this could simply inferred from
      a high forward metric. After some discussion, it was agreed explicit
      signaling was preferred. 

      Additionally, there was some intertwining of requirements with the 
      signaling of other OSPF link attributes. Now that these are resolved
      we can move forward with this draft.

Document Quality

   This document has been a WG document for more a year. There have
   been several iterations due to the controversy over area-wide versus
   neighbor signaling. Now that we have reached consensus, the document
   is fairly stable from a protocol standpoint. There has been some 
   discussion on the use cases and they have been refined in the current


      Acee Lindem is the Document Shepherd.
      Alia Atlas is the Responsible Area Director.