Re: OSPF slow reconvergence

Matt,
try to google OSPF tuning, there is quite q bit of good articles
covering the subject. As for Dynamips, you should not rely on it for
this sort of performance tests, it is always going to show poor results
because it runs as a regular bunch of threads and compete for CPU
resources with other applications running on top of host OS. Try it on a
real gear, there are remote labs out there which you can play with just
for 12 dollars per 3 hours.

HTH
A.

On 4/30/2011 12:00 AM, Matt Sherman wrote:
> Hello,
>
> Just curious if anyone can shed some light on this. If you have OSPF hello
> and dead timers set to 1 and 4 respectively, shouldn't OSPF reconverge
> within 4 seconds of the loss of a neighbor? When I look at the routing
> debugs in Dynamips it takes 6 seconds from the notification of OSPF being
> down until the alternate route is added into the table.
>
> I have a real world scenario where we are peering Cisco ASA firewalls with
> Nortel ERS 8600 switches. The lowest the Nortel / Avaya engineers will
> allow us to go down to is 1 and 4. The switches do not have millisecond
> timers anyway so the lowest possible is 1 and 2. It's taking close to 10
> seconds in that case which is not a good thing for VOIP.
>
> Just wondering if this is the expected behavior for OSPF. The Avaya
> engineers don't think so but testing in Dynamips seems to confirm it is.
>
> Thanks,
> Matt
>
>
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Received on Sat Apr 30 2011 - 00:14:31 ART