Vlan Issue

[Bjeurn]

Hi

I'm quite new to Proxmox VE and would like to seek some advise.

Let's say I have a device on the network that is behind a switch with access port in VLAN 3. The device has an IP assigned statically. On the other end, I have a VM running on the hypervisor, there is a linux bridge (vmbr2) that has the VLAN aware tag enabled with a trunk on the switch (vlan 3) and the vlan been added on the on the VM on the networking tab. If i'm not mistaken, this should be to correct approach to be able to communicate in both ways ?

For now, this is not working. However, when I add the a Linux VLAN (same physical port) with an IP, I'm able to communicate bidirectionally.
Any tips? Am I doing something wrong?

 

[ggoller]

Hi!
this should work.
Could you show me the output of:

cat /etc/network/interfaces
cat /etc/network/interfaces.d/sdn
bridge vlan show
qm config <your_vmid> | grep net

?

 

[Bjeurn]

strange, I don't see it atm.

vmbr1 is marked as vlan aware and the tag has been added on the VM under the nic.


This should be output you are looking for, right?

vmbr0 1 PVID Egress Untagged
vmbr1 1 PVID Egress Untagged
vnet01 1 PVID Egress Untagged
tap100i0 1 PVID Egress Untagged
tap101i0 1 PVID Egress Untagged
fwbr101i0 1 PVID Egress Untagged
fwpr101p0 3 PVID Egress Untagged
fwln101i0 1 PVID Egress Untagged

This is the output for /etc/network/interfaces
auto vmbr1
iface vmbr1 inet manual
bridge-ports nic2
bridge-stp off
bridge-fd 0
bridge-vlan-aware yes
bridge-vids 2-4094

Just to test, I tried to remove the uplink on the bridge and add a vlan tag under the nic settings for 2 VMs and i'm able to ping bidirectional. After adding the nic back to the brdige, a ping (to the Linux VLAN I created on the same NIC) from both VMs is still not working.

I'll do some additional testing tomorrow.

 

[Bjeurn]

Update: got it to work. It seems I made a small mistake somewhere which caused confusion. Thanks for the support!

 

[AlisonDe]

VLAN issues in Proxmox can be a real headache to track down. I’ve run into similar behavior before, and it usually ends up being a mismatch between the Proxmox bridge settings and the physical switch configuration.
Double-check that your Linux Bridge (usually vmbr0) has the 'VLAN aware' option checked in the Network settings. If that’s already on, it’s worth verifying that the physical switch port is actually set to 'Trunk' mode rather than 'Access' mode for those specific tags. Sometimes a simple mismatch there is all it takes to drop the traffic.