Virtual Networking

[Michael Vanecek]

I have a little computer shop and would like to separate my family 
network from the shop network so I don't have to worry about virus 
infections across the network and whatnot. One option is to add another 
NIC to the system - but I'm out of slots. Another option is to stick on 
a USB network adapter. However, isn't it possible to assign 2 network 
addresses to a single NIC? As in, the physical interface being 
192.168.192.* and the virtual IP being a different network address 
altogether - allowing me to effectively isolate it while allowing both 
networks to access the gateway address 192.168.192.1? Any pointers to 
documentation would be greatly helpful. I use Gentoo as my gateway and 
firewall.

Thanks,
Mike