DMVPN behavior question

[Michael Pagan]

I have successfully setup DMVPN between 28XX and 29XX series routers but there is a behavior with the technology that I am curious about. When the tunnels are up and working everything is working great. I have noticed that if the WAN connection drops (mine are primarily Ethernet connections) the affected VPN connection drops and does not recover until I issue a shutdown/no shutdown command on the tunnel0 interface.

Is there a way to configure my routers to reattempt to make a connection without having to manually shutdown the tunnel0 interface? I can post my configs if helpful, but they are about as vanilla as you can get since I follow the DMVPN wizard found in the Cisco Configuration Professional utility.

Thanks for any information you can provide.

Mike

[Joseph W. Doherty]

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Posting

How current is the IOS versions?  I've seen similar problems on p2p VPN tunnels that seemed to be corrected after updating the IOS.

[Michael Pagan]

I updated to 15.2 something (i dont remember for sure right now) but this really did not change the behavior.  In my lab setup I pulled ths WAN connection for a hub (i have dual hubs setup) and the conection didn't recover for 45 minutes.  After that it fired back up.  I saved the logging message but im not at my co?puter now so I can post them later.

[Kishore Chennupati]

perhaps check the bug tool kit to see if your IOS has any related bugs or post your IOS here. Joseph Doherty is a gun with DMVPN's. He will be able to tell you like that

[Jeff Van Houten · Accepted solution]

Make sure you have Ike keepalives on the remote ends. This will force the tunnels down when there is a wan drop, and you're more likely to get a renew when the connection is restored.

Sent from Cisco Technical Support iPad App

[Michael Pagan]

What command do I set the keep alives with.  I dont remember seeing any keepalive lines in the config.  When i get back to my computer i can double check.

[Jeff Van Houten]

Crypto isakmp keepalive

Sent from Cisco Technical Support iPad App

[Michael Pagan]

Sorry for the slow response.  It appears that this was the line that I needed to recover from WAN issues faster.  It worked well when I had the routers on my desk so now that they're in the field I expect them to work the same.

Mike