Advertising L2 Bundle Member Link Attributes in IS-IS
draft-ietf-isis-l2bundles-07

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>, isis-chairs@ietf.org, akatlas@gmail.com, rfc-editor@rfc-editor.org, hannes@gredler.at, draft-ietf-isis-l2bundles@ietf.org, isis-wg@ietf.org
Subject: Protocol Action: 'Advertising L2 Bundle Member Link Attributes in IS-IS' to Proposed Standard (draft-ietf-isis-l2bundles-07.txt)

The IESG has approved the following document:
- 'Advertising L2 Bundle Member Link Attributes in IS-IS'
  (draft-ietf-isis-l2bundles-07.txt) as Proposed Standard

This document is the product of the IS-IS for IP Internets Working
Group.

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

A URL of this Internet Draft is:
https://datatracker.ietf.org/doc/draft-ietf-isis-l2bundles/


Technical Summary

  There are deployments where the Layer 3 interface on which IS-IS
  operates is a Layer 2 interface bundle.  Existing IS-IS
  advertisements only support advertising link attributes of the Layer
  3 interface.  If entities external to IS-IS wish to control traffic
  flows on the individual physical links which comprise the Layer 2
  interface bundle link attribute information about the bundle members
  is required.
  The extension in this document are mostly used for:
  1) telemetry applications which build segment-routing stacks such that 
  child-links of a bundle can get probed.
  2) TE to manage the load on child links if there is an imbalance.


Working Group Summary

  There was some controversy mostly triggered by
  network operators that the use-cases are not clear and
  wether IS-IS is the correct place for these extensions.
  BGP-LS was suggested as an alternative, mostly
  because BGP-LS is a strict northbound protocol
  and this would be the precedent-case for a pure-northbound
  protocol (= no receive side logic) in IS-IS.

  Alia raised awareness in OSPF, IDR, and RTGWG during the IETF Last
  Call to see if there were any concerns about this technical path 
  forward and had a response that this direction can work for OSPF as 
  well.  Given the implications for an l2bundle being an IEEE Link 
  Aggregate Group (LAG), Alia also raised awareness on the ieee-ietf-
  coord about the IETF LC, but without any response.

  While the draft shepherd clearly would prefer a different technical 
  solution, there was clear WG consensus to publish and no discussion or 
  disagreement at IETF 98.

Document Quality

  There is one implementation for Cisco IOS-XR.  At IETF 98 ISIS WG, 
  when this draft was discussed, Les mentioned that Cisco is awaiting 
  the IANA code-point to ship this feature.

Personnel

 Hannes Gredler (isis-wg co-chair) is the Document Shepherd.
 Alia Atlas is the AD.