Flapping Links and OSPF

Unanswered Question
Jan 14th, 2009

Hi all,

I'm using OSFF in my network. I have my primary links via fibre and b/up via leased lines. Whenever there a flapping pri link, my remote site registers as down because OSPF keeps on looking for the best path using the fibre link which keeps on going up n down. Is there away whereby i can switch all traffic to leased line whenever service degrades within the fibre links without having to manually intervene & shut down the offending link?

I have this problem too.
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Giuseppe Larosa Thu, 01/15/2009 - 02:17

Hello Sammy,

OSPF with default timers can take up to 40 seconds to detect that the neighbor is dead.

if the link doesn't go down but it is still up/up the router has to wait for dead-interval timer expiration.

Depending on your IOS image you may think to use OSPF fast hellos that can reduce dead interval to 1 second with subsecond Hello frequency.



Hope to help



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