Ping appears to "wake up modem"

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Nov 6th, 2007
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Using a Cisco 1711 as a remote talking to a hub. Using GRE+IPSEC tunnels to communicate and establish EIGRP neighbor adjacencies. Tunnels go down after it appears the crypto tunnels go down. By simply pinging the gateway(modem) everything comes up immediately, then it goes down again. The GW ip address is staying the the 1711's arp cache. Any ideas out there as to what is going on? Faulty modem?

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Richard Burts Tue, 11/06/2007 - 12:40
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It might be helpful if you posted the config of the 1711 so that we can see how it is set up. I have configured IPSec/GRE tunnels with EIGRP quite a few times and I have not experienced the symptoms that you describe.

If the crypto tunnels go down then I would expect that the GRE tunnel would stop working. Are there any log messages generated that might help? At the point where the tunnels have stopped working can you do show crypto engine connection active and post the output? Can you also do show crypto ipsec sa and post the output?



mknewnam Wed, 11/07/2007 - 05:20
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Thanks for the reply. Increasing the arp timeout fixed this problem, but I'm not sure why.


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