Re: [Lsr] draft-ietf-lsr-isis-rfc5306bis-01

[Uma Chunduri <[e-mail]>]

Les,


*[Les:] The timers (T1, T2, T3) are NOT relevant to PR/PA.*
>
> *PR is sent BEFORE a router does a restart to alert the neighbors that the
> signaling router’s control plane is going away for a time.*
>
> *RR/RA are associated with what happens AFTER the router has restarted and
> now wants to reacquire adjacencies/LSDB.*
>

Thx. Yes, I got that.


>
> *I do not know what text in the draft suggests to you that there is any
> relation between PR/PA and RR/RA.*
>


Newly added Section 2.2.3 a says this:



*       The "remaining time" transmitted according to (b)       below MUST
reflect the actual time after which the adjacency will       now expire. *

The above is same for section 2.2.1 a, which talks about RR and RA.
This is the reason, I asked, what is the implication of same timer value
here for PR/PA.
For example, what are the implications of this new timer times out before
the value specified in RA (as PR is obviously initiated before) ? Also see
my original question.



> *[Les:] What constitutes a topology change significant enough to trigger
> bringing down the adjacency is an implementation decision.*
>
> *Definition of the conditions is NOT an interoperability issue and
> therefore does not fall within the scope of the draft.*
>
>
>


I would have agreed with the above statement if this is the guidance for
the restarting router. Here the topology change is detected by the
neighboring router (see your text below)  and you do want a consistent
behavior from neighboring node from any vendor.  No?

Section 2.2.3






*"  While a control plane restart is in progress it is expected that the
 restarting router will be unable to respond to topology changes.  It   is
therefore useful to signal a planned restart (if the forwarding   plane on
the restarting router is maintained) so that the neighbors   of the
restarting router can determine whether it is safe to maintain   the
adjacency if other topology changes occur prior to the completion   of the
restart. "*


--
Uma C.