Kent, Acee, and Padma-

On Broadcast/NBMA segments, OSPFv2 identifies neighbors
by their IP interface addresses, not Router IDs (see Section
10.5 of RFC 2328). That's why there is an IP Interface
Address in the grace-LSA -- so that the helper can correctly
identify the neighbor to help. Note that on Broadcast/NBMA segments
the helper may possibly receive the grace-LSA from a router
other than the restarting router itself.

John

> -----Original Message-----
> From: Kent Wong [mailto:wongkentHOTMAIL.COM]
> Sent: Thursday, December 06, 2001 2:31 PM
> To: OSPFDISCUSS.MICROSOFT.COM
> Subject: Re: Questions and comments on
> draft-ietf-ospf-hitless-restart-01. txt
>
>
> Hi John,
>
> Thanks for the reply.
> I have another question: Why do we need to attach IP
> Interface Address in
> Grace LSA for Broadcast and NBMA interface? Isn't the
> advertising router
> field in the Grace LSA sufficient enough to identify the
> restarting router
> in the Broadcast/NBMA segment? Thanks.
>
> ---Kent
>
> >From: "Moy, John" <John.MoySYCAMORENET.COM>
> >Reply-To: Mailing List <OSPFDISCUSS.MICROSOFT.COM>
> >To: OSPFDISCUSS.MICROSOFT.COM
> >Subject: Re: Questiosn and comments on
> draft-ietf-ospf-hitless-restart-01.
> > txt
> >Date: Tue, 4 Dec 2001 15:35:00 -0500
> >
> >Kent-
> >
> >Thanks for the good comments. As for your comment #1,
> >I intended that the helper perform your Option (ii),
> >reevaluating the grace period based on the contents of the
> >new grace-LSA. This also means that if any of the tests 1-4
> >of the draft's Section 3.1 fail for the new grace-LSA, the
> >helper will exit helper mode. I will add this to the draft.
> >
> >As for comment #2, I agree, and will reword bullets (1) and
> >(2) at the top of page 6 accordingly. You can still tell whether
> >you should exit hitless restart by looking at your pre-restart
> >LSAs, but it will no longer be a simple memory comparison.
> >
> >And yes, as in your point #3, anywhere the draft references
> >AS-external-LSAs it should also reference NSSA's type-7 LSAs.
> >
> >John
> >
> >
> >-----Original Message-----
> >From: Kent Wong [mailto:wongkentHOTMAIL.COM]
> >Sent: Sunday, December 02, 2001 5:49 PM
> >To: OSPFDISCUSS.MICROSOFT.COM
> >Subject: Questiosn and comments on
> draft-ietf-ospf-hitless-restart-01.txt
> >
> >
> >
> >Hi John,
> >
> >I have read your draft-ietf-ospf-hitless-restart-01.txt and
> would like
> >to raise a couple questions and comments:
> >
> >1. Behavior of Helper receiving Grace LSA after entering helper mode?
> >
> >In your draft, you didn't specify what the helper's behavior
> should be when
> >it receives a Grace LSA again (from the same restarting router who
> >sent the Grace LSA before). I think the helper can either:
> >(i) ignore that Grace LSA after it enters helper mode OR
> >(ii) accept it and reset the Grace period based on the new Grace LSA.
> >Should this behavior be specified in the draft?
> >
> >2. Conditions to exit hitless retart
> > The draft specifies that a restarting router can exit
> hitless restart
> >successfully
> > if the router/network LSA it is going to build is the same as the
> >router/network LSA
> > it has last originated before the restart.
> > How about the case that before the router restarts, one of the
> >neighbors
> >is not
> > in Full state and so it does not include it in its
> router/network LSA
> >but
> >then
> > after it restarts, it somehow forms Full adjacency with
> that neighbor
> >before
> > other helper neighbor. In that case, the router/network
> LSA it is going
> >to build
> > will never be the same as its pre-start LSA and it
> cannot exit hitless
> >restart
> > successfully and need to wait for grace period to expire
> even it has
> >gained back
> > all its previous adjacencies.
> >
> > e.g. The pre-start network LSA contains nbr B, C, D
> > but the new network LSA it is going to build will
> contain A, B, C,
> >D
> >
> >
> > Maybe the exit condition should be changed to as long as it has
> >acquired
> >all the
> > previous adjacenies B, C, D, it can exit and the
> router/network LSA
> >does
> >not need
> > to be exactly the same?
> >
> >3. A minor comment on p.5 point (3), NSSA External LSA can
> be mentioned
> >too.
> >
> >Thanks!
> >
> >---Kent
> >
> >
> >
> >
> >
> > _____
> >
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> >
> >
>
>
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