Hi everybody!
I am experiencing a behaviour of ovirt, of which I don't know whether it
is expected or not. My setup is as follows:
A virtual machine has a logical network attached to it, which is
configured without vlan-tagging and listens to the name 'trunk'.
The VM is running an openvpn server. It is a patched openvpn version,
including vlan-tagging. That is, openvpn clients get a vlan tag. This
should not really be an issue but should satisfy the "why do you want to
do it in the first place"-questions.
Anyhow, effectively, the VM simply puts vlan-tagged ethernet-frames on
the virtual network. These frames, however, never make it to the host's
network bridge, which represents the logical network.
My observations are: According to tcpdump, the vlan-tagged packages
arrive at the "eth1"-interface inside the VM (which *is* the correct
interface). Again, according to tcpdump, these packages never arrive at
the corresponding network-bridge (i.e., the interface 'trunk') on the host.
I know that the setup itself is feasible with KVM---I have it working on
a proxmox-machine. Therefore, my conclusion is, that ovirt doesn't like
vlan-tagged ethernet-frames on non-tagged logical networks, and somehow
filters them out, though I don't really see on what "level" that would
happen (Handling the ethernet frames should be a concern of
KVM/QEMU/Linux only, once ovirt has started the VM).
So this problem could be a CentOS issue, but I really don't see why
CentOS should act differently than debian does (proxmox is debian-based).
Is this a known/wanted/expected behaviour of ovirt, and can I somehow
prevent or elude it?
Any help is much appreciated! Of course I am happy to provide more
information if that helps helping me :)
Regards,
Felix