Comments on ipSpace.net: Prefix-Independent Convergence (PIC): Fixing the F...

Ivan, You mentioned router not always have an LFA...

2012-02-20T03:19:07.907+01:00

Ivan,

You mentioned router not always have an LFA.

This true and depend of topoogy, ring topology for exemple is a good case.

Remote LFA will address this caveats. Remote LFA wil compute the PQ node and then establish a dLDP session with PQ node and establish a MPLS tunnel automatically.

PQ node is the first node not sending traffic back to the router.

Cisco implementation will be available in march 2012.

Bertrand (PM LFA, ISIS & BGP)

Hmmm, are you supporting my theory of your thought...

2012-01-27T17:14:49.555+01:00

Hmmm, are you supporting my theory of your thought process, or my Thursday night binge? :)

Wow Tim! You are magician!

2012-01-27T17:11:39.211+01:00

Wow Tim! You are magician!

Attaboy!

2012-01-27T17:01:58.774+01:00

Attaboy!

I'm sure that I'm way off here, but it'...

2012-01-27T16:57:11.486+01:00

I'm sure that I'm way off here, but it's Friday and I'm hungover, so I'm using that as my excuse.

Perhaps you are delving into a comparison of optimizations used for RIB-to-FIB convergence time for the routing protocols vs. what would be required in a controller-based OpenFlow environment.

Good guess, and definitely another interesting top...

2012-01-27T14:51:15.930+01:00

Good guess, and definitely another interesting topic (thank you!), but not even close.

BTW, with LFA we don't always have loop-free alternative (Pierre Francois' presentation addressed that in details).

May be you start from here IGP-based “restoratio...

2012-01-27T08:28:40.243+01:00

May be you start from here
IGP-based “restoration” techniques have one important problem. During the time of re-convergence, temporary micro-loops may exist in the topology due to inconsistency of FIB (forwarding) tables of different routers. This behavior is fundamental to link-state algorithms, as routers closer to failure tend to update their forwarding database before the other routers.

Postet from here:
http://blog.ine.com/2010/06/02/ospf-fast-convergenc/

With LFA we always have Loop free alternative and avoid micro-loops during convergence. And you want to describe that nowtime something is changed?

Or maybe LFA applicabilityin SP networks?
http://tools.ietf.org/html/draft-ietf-rtgwg-lfa-applicability-06