This should also be useful with the pending 'veth' driver, as it
emulates two ethernet ports connected with a cross-over cable.

To make this work, you have to enable the sysctl (look Dave,
no IOCTLS, there might be hope for me yet!! :)), and in your
application you will need to use SO_BINDTODEVICE (and probably bind to
the local IP as well).  Some applications such as traceroute already
support this binding..others such as ping do not.

You most likely will also have to set up routing tables using
source IPs as a rule to direct these connections to a particular
routing table.

Comments welcome.

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com