I have the following configuration on my router. Both router A and router B show the tunnel 0 interface is up, line protocol is up. I can ping 188.8.131.52 and 184.108.40.206 from both router A and router B. When I try to ping 172.20.42.17 from router A the ping fails. I can ping172.20.42.1 from router A (itself) without any problems. The same is true for router B, I can ping 172.20.42.17 (itself), but not 172.20.42.1 the other end of the tunnel.
Does anyone know why the tunnel interface would say up and up but be unable to ping the other side of the tunnel when I can ping both the source and destination addresses of the tunnel endpoints? I can only think that it would be a routing issue but, I'm not sure what I am missing. Any help would be appreciated.
interface Tunnel0 ip address 172.20.42.1 255.255.255.224 ip pim sparse-dense-mode tunnel source 220.127.116.11 tunnel destination 18.104.22.168
interface Serial0/1 ip address 22.214.171.124 255.255.255.252 ip pim sparse-dense-mode no ip mroute-cache load-interval 30 no fair-queue no cdp enable
ip route 172.20.42.17 255.255.255.255 Serial0/1 ip route 126.96.36.199 255.255.255.255 Serial0/1
interface Tunnel0 ip address 172.20.42.17 255.255.255.224 ip pim sparse-dense-mode tunnel source 188.8.131.52 tunnel destination 184.108.40.206
interface Serial0/0 ip address 220.127.116.11 255.255.255.252 ip pim sparse-dense-mode no ip mroute-cache load-interval 30 no fair-queue no cdp enable
ip route 172.20.42.1 255.255.255.255 Serial0/0 ip route 18.104.22.168 255.255.255.255 Serial0/0