[Openswan Users] IPSec Tunnel up, but no traffic

[Will Roberts]

Hello,

I'm having a problem with a tunnel between two hosts. The IPSec tunnel 
comes up without a problem, but when I try to establish the L2TP tunnel 
using xl2tp it doesn't succeed. Using tcpdump on both sides I can see 
ESP packets leaving the machine initiating the tunnel, but I can't see 
them arriving on the other side. I've run 'ipsec verify' on both ends 
and everything checks out.

I can use both endpoints as participants in other tunnels and they work 
correctly in that case. Additionally this has worked in the past, but 
unfortunately I'm not sure what caused it to start failing.

Any thoughts on where I can start looking?

Thanks,
--Will