This test sends two streams of ESP packets towards west.

The packets inside are identical.
The keying on the outside is not. The implication is that one stream
is "impersonating" the other.

The firewall is setup such one stream goes to the normal "eth0", while
the other stream is reflected back to "eth1".

The script "send.sh" was used on "east" to produce the streams.
Netdude was then used to interleave the results and get rid of the ARP
packets.