Dual port NIC and switching

[José Pablo Méndez Soto <auxcri gmail com>]

Hello,

How can I use network manager so that I can plug my girlfriends laptop into port 1 of my computer, while port 0 is plugged to the loooong cable that goes back to my encore 8 port switch and from there to my DSL modem?

I have tried to use bridge-control tools, and also acitvated packet forwarding like this: echo "1" > /proc/sys/net/ipv4/ip_forward

I think the problem is around here:

me@pc:~$ ifconfig
eth1      Link encap:Ethernet  HWaddr 04:4b:80:80:80:03  

          inet addr:192.168.1.4  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::64b:80ff:fe80:8003/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
         
eth0-eth1 Link encap:Ethernet  HWaddr 04:4b:80:80:80:03  

          UP BROADCAST MULTICAST  MTU:1500  Metric:1
         
See how the 2 ports have same MAC? How can I configure network manager to handle 2 different ports? And how would I go about configuring it to route packets out to the internet coming from my chicks's laptop?

Ubuntu 10.10
Asus Crosshair mobo version 1

Thanks,