On 10/19/2009 03:18 AM, Daniel Berteaud wrote:
Le lundi 19 octobre 2009 à 09:14 +0200, Chris Lalancette a écrit :
Sascha Frey wrote:
Hi,
I met a problem setting up virt-manager and libvirt:
I want to use an existing customized network bridge with libvirt (I need special iptables rules and a custom DHCP setup).
So I created a network definition file like this: <network> <name>NAT</name> <bridge name='br-nat' /> </network>
Unfortunately, I'm unable to activate this network, because libvirt tries to create the bridge `br-nat' and fails, because it already exists:
# virsh net-start NAT error: Failed to start network NAT error: cannot create bridge 'br-nat': File exists
I just want libvirt to attach the guest's tap devices to this existing bridge. I don't want libvirt to manage the network.
Is there any chance to realize this set-up? It should work with virt-manager using the graphical wizard.
Yes, just don't define a new network. To use existing bridges, you just need to edit your guest XML files to use something like:
<interface type='bridge'> <mac address='00:16:3e:4a:f6:89'/> <source bridge='br0'/> </interface>
Note that configured bridges should also show up in virt-manager, I believe.
Existing bridge shows up in virt-manager when run on the local machine. If you use a remote connection (at least qemu+ssh), you don't see it, you need to manually edit the guest XML.
(btw, is this a known "problem" or a bug ?)
For a while, libvirt didn't support a way to enumerate bridge devices on a remote machine. That support now exists, but virt-manager needs to be updated to use it (nontrivial). Known issue. - Cole