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1701 Losing Static Routes??

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syncreon

Technical User
Apr 4, 2007
16
GB
Hi all,

Can anyone shed light on this problem? We have a router that keeps being flagged up by our Nagios alert monitoring as being offline for short periods of time. We managed to find out that the router is losing its static routes to our networks.

Using the sh ip route returned 0 results. Yet after reloading the router the same command listed all 20 or so static routes which we had pre-programmed. This is starting to happen more frequently and is disrupting our network.

Can anyone give me help on this?

Thanks.
 
are any interfaces flapping on your router?
are the next hop addresses reacahble?
if not then your router will remove them from the routing table.
 
Yes, exactly; you can make the routes permanent, but you would be much better off trying to figure out why they are being removed from the routing table.
 
Forgive my dumbness here guys but what do you mean by are any interfaces "flapping"?

The router works fine with all the static routes there, next hops, traffic routing the correct way etc. But it just appears sometimes to lose all its routes. I'm not sure if this is faulty hardware or something faulty elsewhere? We have tried switching ethernet cables, using a different port on a different switch yet nothing changes..we still lose the routes at random times.
 
That's what they mean by an interface flapping---it goes on-off-on-off very rapidly. Other than a flapping interface, the only other thing I can think will cause this is using dynamic frame-relay maps, but of course that would require the use of frame relay, and the routes could be lost only after a reboot if one or more static maps are in use.

Burt
 
Ok thanks. What would cause an interface to "flap"? Can it be resolves? Is their any way of confirming this is the case or troubleshoot?
 
when you do a show log do you see your interfaces going up and down?

are these static routes going over a wan or into your lan?
the problem here is we dont know your topology and technologies being used to its hard to say where to look other then the log.
 
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