Server Fault is a question and answer site for system and network administrators. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have ran the following;

sudo /usr/sbin/brctl addbr br0
sudo /usr/sbin/brctl  addif br0 eth0

And added the following to /etc/network/interfaces;

auto br0 # for XPProxx86 KVM
iface br0 inet dhcp
  bridge_ports eth0
  bridge_stp off
  bridge_maxwait 0
  bridge_fd 0

This works perfectly; My XP VM can see the LAN and be reached via the LAN on my laptop. I have another VM I want to do the same with; so I am running two fully reachable VMs on my laptop. I have ran;

sudo /usr/sbin/brctl addbr br1

But then I get the following error;

sudo /usr/sbin/brctl  addif br1 eth0
device br1 already exists; can't create bridge with the same name

Is it not possible to have two VMs on my laptop (which only has one NIC) with access to the local network and be individually accessible from other LAN hosts? I don't want the to be NAT'ed.

share|improve this question
up vote 2 down vote accepted

show us brtctl show

You can have more bridges, but you don`t need one bridge for each VM! my interfaces (with serving 9 VMs):

auto eth0
iface eth0 inet manual

auto br0
iface br0 inet static
        # dns-* options are implemented by the resolvconf package, if installed
        bridge_ports eth0
        bridge_fd 0
        bridge_maxwait 0
        bridge_stp off
share|improve this answer
Hi ThorstenS, yes that is exactly the mistake I have made. I have given each VM their own MAC addresses, thats all that matter, I see know they can share the same bridge adapter. – jwbensley Dec 16 '11 at 16:38

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.