[SOLVED] Problem with double tagged VLAN packets in egress interface

noc.tlc

New Member
Oct 31, 2024
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Hi all,
we have a scenario with a system that produce packets with double tag 802.1Q, can't communicate in egress direction.
The chain is: metroETH-->proxmox hv-->virtual router
In this direction we view the packet with double tag correctly, in normal way, we have a phisical interface enp3s0f1 attached on a vmbr5 with VLAN Aware, and the virtual router have a ether2 attached on vmbr5.

In this case, if we trace, in the pcap file, the packet is correctly double tagged in ingress.
The virtual router have a pppoe server on the INNER VLAN of the VLAN Stacking 802.1Q and respond correctly with a packet double tagged.

I take a tcpdump on the phisical interface of the node, the enp3s0f1, and we view packet with double tag 802.1Q in respond to the discovery received from a pppoe client.

Here is the problem, if i trace on port of MetroETH Switch, rx direction, the packet are single tagged, with only the inner VLAN.
The egress of the phisical port of proxmox node, seems to drop the first packet, despite the tcpdump pcap trace have the packets with double tag?
On the MetroETH switch we have other port with the same configuratione attached on other router with no problem.

Why on the ingress towards is all OK and in egress the outer VLAN disappear?
Thanks to anyone who can answer us.

Proxmox 8.2.7
 
Last edited:
Can you please post your network and VM configuration? (/etc/network/interfaces and qm config <vmid>)
The packets arrive at the virtual router with both tags? But leave proxmox with only one tag?
 
Hi all,
we have tried some configuration, pci passthrough too, but the same thing appen, leave proxmox with only one tag.

But, we have tried to change the ethernet NIC and the problem disapper.
With the Qlogic NIC, yes, the packets arrive at the virtual router with both tags, but leave proxmox with only one tag.
With the Intel 82599 NIC, the packets arrive at the virtual router with both tags, and leave proxmox with both tags.

Same configuration of networking and VM NICs.

Evidently, the problem is the hardware firmware or the hardware driver at the firmware level of the Qlogic NIC.
At this moment, the functionality is regular with standard vmbr bridge with VLAN Aware.

Thank you.
 

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