Subject: [Isis-wg] Questions and Comment on draft-ietf-isis-restart-01.txt

From: Choto Wong <[email-masked]>
Date: Wed, 12 Jun 2002 20:53:14 -0000

Hi,

I have some questions and comments on the isis restart draft:

1. On Page 6
"....a router MAY transmit one or more normal IIHs
 (containing a restart option, but with RR and RA clear) after the
 initial RR/RA exchange, but before synchronization has been
 achieved, in order to extend the holding time of the neighbors
 adjacencies, beyond that indicated in the remaining time field of
 the neighbors IIH with the RA bit set."

When a router does this, should it also extend T3 to be the new
holding time? Otherwise, even though we extend nbr's holding time
for the adjacency, T3 will still expire in a short time and LSP
with OL bit set will be generated and the graceful restart will
fail anyway.

2. Instead of sending normal IIH after initial RR/RA exchange,
would it make more sense that if this is a planned restart,
a normal IIH with a large holding time is sent before the router
going down so that nbr will hold the adjacency until restarting
router finish the complete restart procedure. In that way, there
is no need to send extra normal IIH after initial RR/RA exchange.

3. If T2 on both levels expires/cancelled, it means end of
database resync and if T3 is still running, we should cancel
T3 at this time. Is that correct? The draft did not say this explicitly.

4. On section 4.3.1.1, the draft mentions the behaviour of a router
when it starts for the first time. Does it mean this draft intends to
change the normal ISIS behaviour even though it is not a restart?
That means we need to start T2 (but not T1, T3) for each level even
we start for the first time. However, it may not be desirable to set
the OL bit every time ISIS comes up. This should be decided by the
network admin on individual cases whether to set the OL bit or not.

5. Just for clarification, in the draft, it mentions "own" LSP
many times, sometimes it mention own non-pseudonode LSP, somes
it mention own LSP including pseudonode. Sometimes, it simply
mention "own" LSP. Should we interpretate the "own" LSP as including
pseudonode LSP if it doesn't specify otherwise?

Thanks!

---Kent Wong

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