OSPF flapping links - tuning

[udo.konstantin]

Hello,

In a customer network there is one flat OSPF Backbone area.
Two sites are connected through one laserlink as well a serial provider connection.
The laserlink has 1 GE and the provider line (MAN) has about 100Mb/s.

The idea is to use the laserlink primary because of the 1 GE and the provider MAN as the secondary. Te main problem regarding the laserlink it often flaps because of weather like fog or anything.
I would like to fine tune OSPF for faster convergence and tuning the spf timer.

Is there also a concept for interface dampening for OSPF? And what spf timer are best practice from Cisco?
Thanks
Udo

Sent from Cisco Technical Support iPad App

[Reza Sharifi]

Hi,

What model switch or router and what ver of IOS are you using?

[udo.konstantin]

Hi,

It is a Catalyst 4506-E with 12.2(40)SG

Sent from Cisco Technical Support iPad App

[Reza Sharifi]

Hi,

If the link flaps and make the network unstable, you can change the throttle numbers to make the network more stable

The default timers are below

Initial SPF schedule delay 5000 msecs

Minimum hold time between two consecutive SPFs 10000 msecs

Maximum wait time between two consecutive SPFs 10000 msecs

Have a look at this link on how to change it.

http://www.cisco.com/en/US/docs/ios/12_2s/feature/guide/fs_spftrl.html

HTH

[udo.konstantin]

Hi,

Thanks for the link.
Is there also a best practice from Cisco or let's say the flapping link goes down for ~1500ms and them comes up again....

Which values for the timers should be used if the spf shouldn't run

Thanks
Udo

Sent from Cisco Technical Support iPad App