Hello, I am using shorewall 2.2.3-1 and ipsec-tools-0.5.2 on the same machine. My kernel 2.6.11.10 is patched as needed. The server has an official IP-Adress (no NAT on this side), but some of the clients do use NAT. I figured out that NAT-T connections (RFC 3947) did not work without the "generic:udp:4500" in /etc/shorewall/tunnels: # Road-Warriors ipsecnat net 0.0.0.0/0 road generic:udp:4500 net 0.0.0.0/0 road regards claas