$ nc -g A -g B C 3333 I see packets forwarded over lo to A, and no further packets are sent over lo or eth0. Machines B and C receive no packets.A 127.0.0.1 source address is considered martian by the source validation code as proposed by rfc1812. You should see warnings in the console if you have martian logging enabled.
I see the same behavior when the source address is explicitely bound to an address belonging to a local NIC (-s option to netcat).
$ nc -g B A 3333 I see packets forwarded out over eth0 to B and then back to A but machine A never seems to accept the packets or reply with a SYN or RST.A will do a route lookup of [src=A dst=A] which results in your local route being returned. Again this violates rfc1812 because that route will not be a unicast route but a local one. A martian source warning should be logged if enabled.
Is there any way to enable routing for this case? This is a desirable source route at times. I would hate to have to boot FreeBSD every time I want to use this feature. Tim Newsham http://www.lava.net/~newsham/ - : send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
