Same as netkey-01 but we also add a passthrough route to verify the issue with http://lists.libreswan.org/pipermail/users/2007-April/012298.html mentioned at http://bugs.libreswan.org/view.php?id=907 It will require a manual adding of dir out and dir forward policies, eg ip xfrm policy add dir in src subnet1 dst subnet2 ip xfrm policy add dir out src subnet1 dst subnet2 ip xfrm policy add dir in src subnet2 dst subnet1 ip xfrm policy add dir out src subnet2 dst subnet1 ip xfrm policy add dir fwd src subnet1 dst subnet2 ip xfrm policy add dir fwd src subnet2 dst subnet1 "westnet-eastnet": 192.0.1.0/24===192.1.2.45[@west]...192.1.2.23[@east]===192.0.2.0/24 1) west 192.1.2.45 pings east-in/east-eth0/east 192.0.2.254 on eastnet 192.0.2.0/24 2) west adds an iptable rule to block plaintext from eastnet 3) west pings 192.0.2.254 again, but pong should be dropped by rule 4) west initiates connection "westnet-eastnet"; east 192.1.2.23 responds 5) netjig sends ping packets from westnet to eastnet