I do have a site where we have got internet connection via ethernet port. We did make an ipsec over GRE tunnel from that site to our HO in US.
Router model Cisco 2821 at the remote site and 3845 at HO.
We have got another internet link onto the serial port of the router and made another IPSec over GRE Tunnel to HO router through this link.
The setup running fine. But recently we are having connection issues from the service provider which is providing internet connection via the ethernet port. When that service goes down our EIGRP relationship done over these GRE tunnels is breaking up and we are losing reachability to the site. We have to reach via the second internet link, clear the routes and then only the traffic reachablity is resuming.
My question is to avoid these I want to configure keepalive on the tunnel interface which is being used by the Ethernet internet connection. The tunnel line protocol stays down as and when i configure keepalive on it. but where as the other tunnel being used by the serial internet connection takes the keepalive configuration and working fine.