0

On my current Debian system I use VLAN tagging and I create bridges br-wan and br-lan that I use for LXC containers:

auto lo br-lan br-wan

iface lo inet loopback

iface br-wan inet manual
    bridge_ports eth0.3
    bridge_maxwait 0

iface br-lan inet static
    address 192.168.200.10
    netmask 255.255.255.0
    gateway 192.168.200.1
    bridge_ports eth0.2
    bridge_maxwait 0
      
iface eth0.1 inet static
    address 10.7.1.10
    netmask 255.255.255.0

Now I would like to add a KVM guest that gets transparent access to eth0 and in turn uses VLAN tagging internally (for example, to create a virtualized router routing between eth0.2 and eth0.3). To test, I did the following:

brctl addbr br-master
brctl addif eth0

And then I created a KVM guest with --network=bridge=br-master,model=virtio which creates an interface vnet0 that is also added as bridge port to br-master. Inside the guest added the VLAN interfaces.   On the host, I see tagged packets in vnet0 (tcpdump -i vnet0 -e vlan) and br-master (tcpdump -i br-master -e vlan).   However, the traffic never reaches eth0 on the host.

I am sure the story is not that simple. How can I add such a VLAN-transparent "master bridge" to my system, without disrupting my old config?

0

I have not tried this but it should work with the bridge vlan ... command.

For each VLAN ID you use on vnet0 you have to do this:

for vlanid in 1 2 3 4; do
    bridge vlan add dev eth0 vid $vlanid untagged
done

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

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