Re: OSPF LSA Throttling

Thanks Colt for a quick reply but what you are talking about is SPF
Throttling and what I quoted was for LSA Throttling from the following link:

http://www.cisco.com/en/US/docs/ios/iproute_ospf/configuration/guide/iro_lsa_throt_ps6441_TSD_Products_Configuration_Guide_Chapter.html#wp1054075

<http://www.cisco.com/en/US/docs/ios/iproute_ospf/configuration/guide/iro_lsa_throt_ps6441_TSD_Products_Configuration_Guide_Chapter.html>I
am aware that SPF throttle timer is dynamic and it doubles with each change
but LSA throttle timers don't (that is what I assume as nothing is mentioned
about it in the above link). This is the reason I am have issue with LSA
throttling being dynamic !

Thanks,
Malik

On Fri, Feb 25, 2011 at 7:08 PM, Colt Mercer (comercer)
<comercer_at_cisco.com>wrote:

> Look at this document on the 'timers throttle spf' command. The throttle
> time is a dynamic timer that doubles with each change.
>
>
>
> *Shortest Path First Calculations*
>
> SPF calculations occur at the interval set by the *timers throttle spf** *command.
> The wait interval indicates the amount of time to wait until the next SPF
> calculation occurs. Each wait interval after that calculation is twice as
> long as the previous one until the wait interval reaches the maximum wait
> time specified.
>
>
>
> http://www.cisco.com/en/US/docs/ios/12_2s/feature/guide/fs_spftrl.html
>
>
>
> Colt Mercer
>
> Cisco Systems Inc.
>
>
>
>
>
> -----Original Message-----
> From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of
> Malik Nouman Ahmad
> Sent: Friday, February 25, 2011 9:36 AM
> To: Cisco certification
> Subject: OSPF LSA Throttling
>
>
>
> Hi,
>
>
>
> I was reading about the mentioned subject and came across the following
>
> benefits of it:
>
>
>
> 1. Prior to the OSPF LSA Throttling feature, LSA generation was
> rate-limited
>
> for 5 seconds. That meant that changes in an LSA could not be propagated in
>
> milliseconds, so the OSPF network could not achieve millisecond
> convergence.
>
>
>
> 2. The OSPF LSA Throttling feature is enabled by default and allows faster
>
> OSPF convergence (in milliseconds). This feature can be customized. One
>
> command controls the generation (sending) of LSAs and another command
>
> controls the receiving interval. This feature also provides a dynamic
>
> mechanism to slow down the frequency of LSA updates in OSPF during times of
>
> network instability.
>
>
>
> I understood Point 1 as we can achieve LSA generation in less than 5
> seconds
>
> by specifying appropriate values in "timers throttle lsa all" command,
>
> however, the second point is still unclear. We can modify the same values
> so
>
> that LSA generation can be delayed but how will it be DYNAMIC because the
>
> values that we will specify will be FIXED and LSA generation will have
>
> delayed timers for all the cases, no matter the network is stable or
>
> unstable
>
>
>
> Please clarify the confusion
>
>
>
> Thanks,
>
> Malik
>
>
>
>
>
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Received on Fri Feb 25 2011 - 19:18:43 ART