Bind a port to a network interface
Solution 1:
I think that you can do that using iptables. A rule in IP table should do it, but I think that the NIC in question has to have a IP assigned to it. Try this, just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command(s) below:
iptables -A PREROUTING -p tcp --dport xxxx -i eth1
Replace xxxx with the port number. For more info on iptables see the Manpage