Padma-

The restart reason is included so that the helper has more
information to fuel its policy decision as to whether it really
wants to help. You can omit the restart reason, but a reasonable
assumption would then be that you are trying to recover from an unplanned
outage, which would make it less likely that some people/boxes are
going to help.

Allowing more than one Link State ID opens up the possibility
that the helper could have multiple grace-LSAs from the same
restarting router, with the resulting confusion. You just have to
make sure that the interface is an argument to any troubleshooting
interface which wants to look at link-local LSAs.

John

> -----Original Message-----
> From: Padma Pillay-Esnault [mailto:padmaJUNIPER.NET]
> Sent: Thursday, December 06, 2001 3:12 PM
> To: OSPFDISCUSS.MICROSOFT.COM
> Subject: Re: Questions and comments on
> draft-ietf-ospf-hitless-restart-01.txt
>
>
> Kent,
>
> Agreed. IMHO, we don't need it and same goes for the restart
> reason which is not vital but just informative.
>
> The grace LSA could be simplified with only the grace period.
> Another comment, is about the LSA-ID of 3.0.0.0, It would be
> much easier
> to troubleshoot it the LSA-ID had the interface index ORed in
> it. So I think
> we should relax the lsa-id to be 3.0.x.x to be indentified as
> grace-lsa.
>
> Padma
>
> Kent Wong wrote:
>
> > 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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