OSPF: Interrelationship MD5 Auth <> System Time

Unanswered Question
Jul 12th, 2008
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recently we had a problem with OSPF.

Routers receivded Hellos from their neighbors but sporadically didn't recognize them as Hellos which resulted in loosing the adjacencies.

While troubleshooting we removed MD5-Authentication and then everything worked fine.

Then we noticed that the system time of one router was absolutely wrong because the timeserver had failed.

After setting the router's clock everything worked properly - now with MD5 again.

Now I'm searching a source of information about the interrelationship between the system time and MD5-Authentication in OSPF because I want to understand that behavior.

Can anybody help?

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bvsnarayana03 Sat, 07/12/2008 - 07:44
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System time has no role to play in OSPF adjancies. For adjancies to be established, auth type & key has to be matched, & hello timers on both routers should be same.

Though there are other paameters in Hello packet which 2 ospf routers must match to be adjacent, but they are irrelevant in your case. So to conclude, system time has no role to play.


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