Trunking through to a VM

[jon.langemak]

I've been searching endlessly and cant seem to find the answer here. Im looking to pass VLAN tags from VMs up to the physical network. AKA - my Ubuntu VM is tagging traffic on VLAN 11 and I'd like the bridge (VMBR0) on the ProxMox host to pass that tag along to the physical network.

Anyone done this before?

 

[pirateghost]

I run virtual routers and tag vlans in and out all the time. what issue are you having? As long as your switch supports the VLAN tagging, it will just work.

 

[jon.langemak]

Interesting - so maybe Im just doing it wrong. Let me be more specific to make sure we're on the same page.

I have an Ubuntu VM in Proxmox that is configured to send it's IP traffic on ETH1 (192.168,10.72) tagged on VLAN 11. On the ProxMox side of things, I have a brdige (VMBR1) configured that has a physical interface on the ProxMox host (eth1) assigned to it. There's no VLAN config on the bridge or on the NIC from the ProxMox side of things. The physical switchport that the ProxMox's ETH1 interface plugs into is a trunk accepting all VLANs and there's VLAN interface configured on the switch in VLAN 11 (192.168.10.1)

Is this similar to your setup? Im hoping it is and Im just missing something obvious.

I ran a span on the physical switchport and dumped it out to WireShark. When I source pings from the switch towards the VM I see them being tagged on VLAN 11. When I source pings from the VM towards the switch, I see them in the capture, but they arent tagged.

My theory was that the ProxMox host was stripping the tags but I suppose its also possible that the VM isnt configured correctly. I tried to do a TCPDUMP on the VM to see if I could see the traffic tagged but I didnt have any luck seeing the dot1q tags. I also tried it on the ProxMox host itself but I couldnt see VLAN tags in a TCPDUMP there either.

Any ideas on how to troubleshoot this? I thought maybe I'd need to do PCI pass through with a NIC to get this to work but it sounds like you got it working without that. Im hoping I dont have to do that...

Any help would be appreciated!

 

[jon.langemak]

Well - After running out of ideas, I finally upgraded my ProxMox host to 4.x. Now it works just as expected...

So Im at a loss - something was apparently off with my 3.4 install. I'd still be interested to learn about ways to troubleshoot this and see if theres a way to see the VLAN tags in a TCPDUMP.

 

[pirateghost]

I have an Ubuntu VM in Proxmox that is configured to send it's IP traffic on ETH1 (192.168,10.72) tagged on VLAN 11. On the ProxMox side of things, I have a brdige (VMBR1) configured that has a physical interface on the ProxMox host (eth1) assigned to it. There's no VLAN config on the bridge or on the NIC from the ProxMox side of things. The physical switchport that the ProxMox's ETH1 interface plugs into is a trunk accepting all VLANs and there's VLAN interface configured on the switch in VLAN 11 (192.168.10.1)

Is this similar to your setup? Im hoping it is and Im just missing something obvious.

Yep.

So Im at a loss - something was apparently off with my 3.4 install. I'd still be interested to learn about ways to troubleshoot this and see if theres a way to see the VLAN tags in a TCPDUMP.

TCPDUMP on the vmbr should have shown you everything.

I can attest that tagging VLANs from within the guest works well. I have been running virtual routers for years in ProxMox