I've got a multi-homed host connected to both a UUNET T1 and a PacBell ADSL
connection. Both are commercial accounts with small dedicated netblocks.
The default route is set to use the T1.
I recently added route entries for a couple of low-priority outside hosts
to use the ADSL connection. I now find that connection *from* those hosts
to the T1 interface fails. I'm suspecting it's because PBI is
egress-filtering source addresses not under its control. (Acceptably a Good
Thing.) For instance, I tried ping and found that the ICMP reply is going
back through the PBI connection as expected, but the source address is that
of the T1 interface. (From tcpdump output.)
Is there some way to force those packets to go back out the T1 interface
while still sending packets initiated from this host through my ADSL
interface, perhaps with iproute2 or some route cleverness?
