Does xen bridging support vlan tagged packets
arriving on the physical nic from outside of the xen host to be passed through with the
vlan tag to the vif of the guest with the guest VM receiving the tagged packet ?
Xen does not have any special bridging code, just scripts (releases <=4.1.x) which manipulate the features found in the standard kernel. If you can do it without Xen you should be able to do it with Xen, in this case yes.
We have a xenbr configured with two interfaces - eth3 (physical nic of the host),
vif23.2 (vif of guest VM running in domain 23). Sniffing the packet just outside the
physical NIC does show that it has the vlan tag, but tcpdump on eth3 shows that
the vlan tag has been stripped. Any ideas pls ?
Are you tagging the traffic in the dom0 or the domU? The recommended setup is to tag packets in the dom0 with a network configuration like
dom0 domU
Physical eth3 - [ VLAN eth3.xxx - ( xenbr0 ] - vif23.x )
Where xenbr0 has an IP has an IP on the VLAN if you need to address the dom0 as well, otherwise a null configuration if just the domU.
Here the domU has no knowledge that it is part of a VLAN but the packets are tagged when they pass through the dom0 VLAN interface.
James
