Viewing Tunnel Status
You can look at the attributes for a tunnel with the show interface command.
Router1#show interface Tunnel5
And the easiest way to determine if a tunnel is operational is simply to use a PING test to either the send ICMP packets through the tunnel or to its destination address:
Router1#ping 192.168.66.6
Router1#ping 172.22.1.4
You can use the standard show interface [...]