[fedora-virt] bridged guest networking in f12 with netcf

[Dale Bewley]

Hello all,

I started a blog post about experimenting with netcf and configuring a guest to share the same subnet as the host. It turned into something a bit longer and more rambling of course.

* http://tofu.org/drupal/node/86

At any rate I ran into a few issues while using:
 virt-manager-0.8.0-7.fc12.noarch
 netcf-0.1.4-1.fc12.x86_64
 libvirt-0.7.1-15.fc12.x86_64

= Virt-manager =
I mentioned this one on the virt-tools list already. Virt-manager describes a routed network as a NAT network.

= Bridge =
Another issue was an error while using virsh iface-define. 

Given br0.xml:
<interface type='bridge' name='br0'>
  <start mode='onboot'/>
  <protocol family='ipv4'>
    <ip address='10.10.10.158' prefix='24'/>
    <route gateway='10.10.10.254'/>
  </protocol>
  <bridge>
    <interface type='ethernet' name='eth0'>
      <mac address='00:24:E8:30:20:E7'/>
    </interface>
  </bridge>
</interface>

[root at tofu2 network-scripts]# virsh iface-define br0.xml
error: Failed to define interface from br0.xml
error: invalid argument in virGetInterface

It did work however.

[root at tofu2 network-scripts]# cat ifcfg-eth0
DEVICE=eth0
HWADDR=00:24:E8:30:20:E7
ONBOOT=yes
BRIDGE=br0
TYPE=Ethernet
BOOTPROTO=dhcp
PEERDNS=yes
PEERROUTES=yes
NAME="System eth0"
UUID=5fb06bd0-0bb0-7ffb-45f1-d6edd65f3e03

[root at tofu2 network-scripts]# cat ifcfg-br0
DEVICE=br0
ONBOOT=yes
TYPE=Bridge
BOOTPROTO=none
IPADDR=10.10.10.158
NETMASK=255.255.255.0
GATEWAY=10.10.10.254

But now eth0 is missing from iface-list

[root at tofu2 network-scripts]# virsh iface-list
Name                 State      MAC Address
--------------------------------------------
lo                   active     00:00:00:00:00:00

Presumably, that's because from the libvirt / netcf perspective (which is just looking at the ifcfg files) I have replaced it with the br0 interface. However, br0 is not started, so presumably that's why it isn't listed either. After a 'service network restart' things look sane again.

[root at tofu2 network-scripts]# virsh iface-list
Name                 State      MAC Address
--------------------------------------------
br0                  active     00:24:e8:30:20:e7
lo                   active     00:00:00:00:00:00


= Network =
And finally, after creating this bridge, it would be nice to create a network which utilizes it as follows. That fails the way I attempted to do it.

[root at tofu2 ~]# cat net-bridged.xml 
<network>
  <name>bridged</name>
  <forward mode='route'/>
  <bridge name='br0' />
</network>

[root at tofu2 ~]# virsh net-define net-bridged.xml 
error: Failed to define network from net-bridged.xml
error: internal error Forwarding requested, but no IPv4 address/netmask provided

Presumably that's the goal of http://fedoraproject.org/wiki/Features/Shared_Network_Interface in F13.

Thanks for any comments.