Subject: [Isis-wg] IS-IS Restart draft clarification

From: "Matthew Noble" <[email-masked]>
Date: Fri, 7 Dec 2001 11:25:03 -0000

Mike

In section 4.3.1.2 second paragraph says that SPF is not run while T3 is
running, but in the 5th paragraph of the same section it says that when T2
expires/cancelled, the SPF for that level _is_ run. Now T2 will expire under
normal sucessful conditions before T3 expires - so there is a contradiction
here. I am assuming that the info in the 5th paragraph is correct, and that
that in the second paragraph is wrong.

Could you confirm that for me.

Thanks
Matt

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From: mike shand <[email-masked]>
Date: Fri, 07 Dec 2001 14:24:10 +0000

>Could you confirm that for me.

Without actually looking at the draft, I think the issue is that once we 
have got synchronization we can safely run SPF at that level. Once we have 
got synchronization at both levels we can clear T3. But while one level is 
synchronized and the other is not we still need to keep T3 running.

So yes, I think the second para is strictly wrong.

But I'll look at it in more detail later.

         Mike

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From: "Matthew Noble" <[email-masked]>
Date: Tue, 11 Dec 2001 12:10:58 -0000

Mike

Could I get a further clarification on this draft.

The draft does not explicitly state what the meaning is for the expiration
of timer T2 (as opposed to it being cancelled when we have determined that
the LSP database for that level is sync'd). Can I take it that it is
considered a sucess (or about as close to a success we can get at the time)
and assume that at that point the LSP database for that level is sync'd?
This assumes that timer T3 has not yet expired when the timer T2 expires for
the given level.

Thanks
Matt

> -----Original Message-----
> From: mike shand [mailto:[email-masked]]
> Sent: Friday, December 07, 2001 2:24 PM
> To: Matthew Noble
> Cc: 'Isis-Wg (E-mail)
> Subject: Re: [Isis-wg] IS-IS Restart draft clarification
>
>

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From: mike shand <[email-masked]>
Date: Tue, 11 Dec 2001 12:04:08 +0000

>and assume that at that point the LSP database for that level is sync'd?

Yes. T2 expiration indicates that we have given up on waiting for 
synchronization. This "shouldn't happen", but of course there may be 
pathological conditions where it does, and hence we have to have some way 
of avoiding waiting for ever.

>This assumes that timer T3 has not yet expired when the timer T2 expires for

Yes, in many cases T3 will expire before T2 does.

         Mike