Re: OSPF Performance

Well, you can use "show ip ospf statistics" to figure out how many times things have flapped in some amount of time. The statistics you gather from that effectively tell you the frequency of your flaps, which you can then use to calculate things like the start, increment and max_wait.

throttling SPF does ONLY that though -- it delays the running of SPF. However, it has a similar IDEA as IP event dampening. The difference is with throttling you are delaying the SPF from happening. With dampening you are preventing instability by suppressing the advertisements of LSAs when things are flapping. Both use the same principal of how long to do that for (using exponential decay).

So, to answer your second question it depends on what you want to do or what you are told to do. Do you want to delay SPF calculations during flaps, or do you want to prevent interfaces/networks from being advertised at all during flaps, or both?

HTH

Regards,
Joe Astorino, CCIE #24347

"He not busy being born is busy dying" -- Dylan

----- Original Message -----
From: "Hussam EL Kebbi" <hussamkibbi_at_hotmail.com>
To: ccielab_at_groupstudy.com
Sent: Saturday, May 22, 2010 5:26:14 AM GMT -05:00 US/Canada Eastern
Subject: OSPF Performance

Experts,
According to ine bog: http://blog.ine.com/2009/12/31/tuning-ospf-performance/
timers throttle spf start increment max_wait:is used when dynamic adaptation
to unstable network topologies.
1 - How can we reflect the unstable network topologies timers (in throttle
timers)?for example using: show ip ospf statistics? if so how can we relate
output value to timers so we need to put in timers throttle?
2- It says also dampening would suppress events while throttling simply
increases the response times:
Do we need to use them together?
Thanks
Received on Sat May 22 2010 - 09:52:02 ART