Regular OE to OE machine but now the responder is behind NAT with
a port forward. This should cause shunts to be installed, since
the inner IP cannot be used to build a tunnel.

So this test case is a-typical, as east is now behind NAT, not road.

note: OE-NAT support is coming soon, which would obsolete this test case

1) road pings east's special .123 IP living on nic
2) nic forwards to east
3) east responds IKE_INIT but on IKE_AUTH fails on traffic selector
4) road installs pass
5) road pings leak out, hit east
6) east triggers its own private-or-clear to road
7) road fails on IKE_AUTH, because of wrong traffic selectors
8) east installs pass
9) ping flow in the clear