View Full Version : [all variants] Use two network cards as a network switch with ubuntu server

September 1st, 2009, 02:41 PM
Hi Everybody,

I am wondering if an Ubuntu server with two network cards can perform the same as a network switch.

My situation is the following: my ISP supplies me with a router which works as a DHCP server and WLAN access point. Unfortunately it has only a single ethernet-port, while I want to connect both my Ubuntu server and another computer via ethernet.

Usually one would use a switch in such a case. I don't have a switch, but I have however an extra pci network card. Therefore I wonder if I could use that instead to get the same functionality (and lower power consumption :)) See the figures below.

With a switch:
+--------+ +--------+ +--------+
| Router |<-------->| |<-------->| Server |
| (DHCP) | | | +--------+
+--------+ | Switch |
| | +----------+
| |<-------->| Computer |
+--------+ +----------+

With an extra network card in the server?
+--------+ +--------+ +----------+
| Router |<-------->| Server |<-------->| Computer |
| (DHCP) | +--------+ +----------+

I get the feeling that I have to bridge eth0 and eth1 in the server, but I have no idea how to proceed from there or how to do it.