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LDP Extensions for Optimized MAC Address Withdrawal in a Hierarchical Virtual Private LAN Service (H-VPLS)

Approval announcement
Draft of message to be sent after approval:


From: The IESG <>
To: IETF-Announce <>
Cc: RFC Editor <>,
    l2vpn mailing list <>,
    l2vpn chair <>
Subject: Protocol Action: 'LDP Extensions for Optimized MAC Address Withdrawal in H-VPLS' to Proposed Standard (draft-ietf-l2vpn-vpls-ldp-mac-opt-13.txt)

The IESG has approved the following document:
- 'LDP Extensions for Optimized MAC Address Withdrawal in H-VPLS'
  (draft-ietf-l2vpn-vpls-ldp-mac-opt-13.txt) as Proposed Standard

This document is the product of the Layer 2 Virtual Private Networks
Working Group.

The IESG contact persons are Adrian Farrel and Alia Atlas.

A URL of this Internet Draft is:

Ballot Text

Technical Summary:

   RFC4762 describes a mechanism to remove or unlearn MAC addresses that
   have been dynamically learned in a Virtual Private LAN Service (VPLS)
   Instance for faster convergence on topology change.  The procedure
   also removes MAC addresses in the VPLS that do not require relearning
   due to such topology change.  

   This document defines new procedures for MAC flushing in VPLS, H-VPLS and PBB-
   VPLS services upon access topology changes. These procedures cover additional 
   additional scenarios to that covered RFC 4762 for H-VPLS. MAC flushing is a
   mechanism used to minimize traffic black-holing time when reachability to MAC 
   addresses changes due to topology access changes.

   In particular, this document describes procedures for MTU-s initiated MAC flush 
   when MTU-s is dual-homed to provider edges (PEs) over an active and standby 
   Pseudowires, and the propagation of the MAC flush message over the VPLS core 
   and processing at PEs.  It also describes a new optimized  MAC flush mechanism 
   termed "negative flush" that enables PEs with instances of a VPLS instance to flush
   the MAC entries reachable via the PE where the topology change was experienced. 
   This is opposed to the current procedure defined in RFC 4762 which cause all MAC 
   addresses previously learned to be flushed except those that are learned from the 
   PE that initiates the flush. Lastly, this document defines the MAC flush and optimized
   MAC flush for PBB-VPLS services. 
Working Group Summary:

   This document is an L2VPN Working Group document. It has gone through a few 
   iterations that addressed comments received from the Working group and comments
   from the WG chairs. 

   The draft got good support when it was adopted as a WG draft. The Working Group
   last call got no feedback from the Working Group and the only comments that 
   needed to be addressed were those of the WG chairs.

Document Quality:

   The document has OK quality. It is clear on the technical content and written with 
   reasonable English and layout. 

   The draft has authors from a couple companies that claim to have implemented the 
   solution albeit no interoperability testing was done. 


     Document Shepherd: Nabil Bitar (
     Area Director: Adrian Farrel (

RFC Editor Note