Re: pcmcia ethernet cards
aliasing an interface:
ifconfig IF:XX new_settings up
(eth0 already configured)
ifconfig eth0:0 192.168.2.1 network 192.168.2.255 broadcast 255.255.255.0 up
this will have eth0 as the usual interface, and eth0:0 pointing to the
same hardware nic, but with different network settings.
PS: your configuration, with one of the computers on a single LAN acting
as a gateway between two IP networks, works perfectly here, with only one
nic per computer (afterall, this is what aliasing has been invented for)
PS2: another good solution would be to user a RIP daemon.