VPN connection problem between 3002 and 3015

[msrohman]

All,

I'm attempting to configure an IPSec VPN tunnel between a 3002 and 3015 concentrator. It's configured for network extension mode. The 3015 is behind a firewall (NAT device) . The 3002 is not. It has a public, Internet routable IP address.

Upon boot up of the 3002, it successfully builds the VPN tunnel. However, after about 15 minutes. The 3002 loses the connection to the 3015. The 3015 still states the the tunnel is build. However, no traffic will pass. Once the 3002 loses the tunnel , it tries to rebuild the tunnel over and over...with no success. I have to reboot the device for it to rebuild the tunnel.

I can keep the tunnel up successfully for long periods of time, if I keep a 'ping' running to systems on the other side of the VPN tunnel.

The VPN tunnel is build using NAT-T (Traversal), UDP 4500.

Maybe it's something with the MTU size?

Thanks for your help.

Mike

[msrohman]

I opened up a ticket with Cisco. We disabled IKE Keepalives for this particular VPN , thus far the VPN tunnel hasn't disconnnected. It's been a few hours. Before disabling the IKE keepalives the tunnel would only stay up for 15-20 minutes.