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Updated: draft-zinin-microloop-analysis-01.txt

Subject: Updated: draft-zinin-microloop-analysis-01.txt
From: Alex Zinin
Date: Mon, 23 May 2005 13:48:20 -0700
I've updated the draft that describes the path locking via safe neighbors
technique the micro-loop prevention design team recommended for further
consideration by the WG.

Here's the summary of changes:

 1. Spelled out the safety conditions for networks with symmetrical
    and asymmetrical link costs.

 2. Added a section on handling ECMP

 3. Added a section on the IPFRR repairing router behavior

 4. Added text on delaying the first SPF to collect all updates for
    the single failure and handling multiple topology changes and
    network instabilities.

 5. Clarified normative text


 - Examples of type-B situations
 - Revise the correctness proof in the Appendix

I will ask Bill to check WG consensus on taking this doc as a WG item.
Please read and send your comments to the list.


This is a forwarded message
From: [email protected] <[email protected]>
To: [email protected]
Date: Monday, May 23, 2005, 12:39:26 PM
Subject: I-D ACTION:draft-zinin-microloop-analysis-01.txt

===8<==============Original message text===============
A New Internet-Draft is available from the on-line Internet-Drafts directories.

        Title           : Analysis and Minimization of Microloops in Link-state 
Routing Protocols
        Author(s)       : A. Zinin
        Filename        : draft-zinin-microloop-analysis-01.txt
        Pages           : 15
        Date            : 2005-5-23
Link-state routing protocols (e.g. OSPF or IS-IS) are known to
   converge to a loop-free state within a finite period of time after a
   change in the topology. It is normal, however, to observe short-term
   loops during the period of topology update propagation, route
   recalculation, and forwarding table update, due to the asynchronous
   nature of link-state protocol operation. This document provides an
   analysis of formation of such microloops and suggests simple
   mechanisms to minimize them.

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