VM to trunk.

[Luis92]

Hi there,

I am trying to connect a VM allocated inside Proxmox to a physical trunk. If the switch port is in access mode with its VLAN everything works fine. Although as soon as I turn it into a trunk the connection drops.

The VLAN tag option of the VM makes the connection drop if is in access mode but it doesn't work when trunking. I have tried many configurations with the bridge to no avail. Currently I have the bridge linked to the interface ens34 connected used to connect the switch and the bridge linked to the VM.

For the setup in access mode the bridge must be with VLAN aware enabled.

Any idea how could I establish a connection from the VM to the trunk?

Any help would be greatly appreciated.

Thank you in advance.

 

[spirit]

you need a vlan-aware bridge to transport trunk vlans to the vm, and don't define any vlan tag on the vm proxmox nic configuration. (only inside your vm).

(This is strange that you need to enable vlan-aware for an access mode on your switch, as it's removing vlan tag when traffic is going from your switch to your proxmox node, and it's adding tag for non tagged vlan traffic from your proxmox node to the physical switch)

 

[deer231231]

I also had the same issue but I fixed it doing the following steps:
1) Make sure that that your trunk port is taking tagged packets (this is due to Proxmox's vlan aware setting that tags packets as they roll out)
2) As @spirit said basically just config the vlan id within your VM to your desired VM and no specify vlan ids in the linux bridge interface info on the pve interface
3) Make your bridge interface simple at first and then add stuff in?:
I took the sample linux bridge vlan aware configs from this site:
https://engineerworkshop.com/2019/11/02/configuring-vlans-on-proxmox-an-introductory-guide/
which helped me troubleshoot and diagnose my issues.
auto vmbr1
iface vmbr1 inet manual
bridge-ports eth3
bridge-stp off
bridge-fd 0
bridge-vlan-aware yes
bridge-vids 2-4094

Anywho good luck and hope this helps!

 

[Luis92]

Thanks for your answers guys.

I have tried to set the VLAN from within Debian 10 but still doesn't work. I will try with pfSense and see if it can recognise tags over the trunk.

Thank you once again for the orientation.

 

[deer231231]

Luis42, my setup was a pfSense box -> managed switch (trunk_port being marked as T or tag) -> proxmox VM.
The vlans were setup on the pfsense box and tagged on the managed switch which allowed it to work.

 

[Luis92]

Luis42, my setup was a pfSense box -> managed switch (trunk_port being marked as T or tag) -> proxmox VM.
The vlans were setup on the pfsense box and tagged on the managed switch which allowed it to work.

So I am going to try something similar, pfSense VM inside proxmox to tag traffic going out to the managed switch. Hopefully I will need only one link coming out of Proxmox which is what I am trying to achieve.

 

[deer231231]

ahhh I had a physical machine for my PFsense setup. Hope it works out!