Question : Problem: Cisco 831 IPSEC Tunnel

I have a bunch of Cisco 831 and SB101 Routers that I am trying ot run IPSec tunnels on.  I don't think the tunnels are actually using IPSec.  How can I tell if they are running IPSec or not?

Answer : Problem: Cisco 831 IPSEC Tunnel

the message kind of sounds like the router is receiving non-crypto packets over the tunnel or something. IP protocol 17 is UDP. It may be more a symptom than a cause though. If adding mode transport doesn't fix it, please post your running configuration again from both sides and let's have a new look.