Proxmox Bond NICs and VLANs

Apr 17, 2022 · 3 mins read

virtualization proxmox hypervisor home lab vlan nic bond

In the video below, we show how to configure Proxmox to use multiple network interfaces and support VLANs

We show how to bind multiple interfaces together for more network throughput or network redundancy

And cover how to re-configure the management interface so it’s in your management VLAN

NOTE: Because we are switching to VLANs, the hypervisor will now no longer be accessible. However, connectivity will be restored in the next step so make sure you have the means to modify the network switch attached to the hypervisor

We show how to configure a network switch to support VLAN tagging for Proxmox

And how to add additional VLAN interfaces to Proxmox as well as how to configure virtual machines to support VLAN tagging

Useful links:
https://pve.proxmox.com/wiki/Network_Configuration#_vlan_802_1q

Steps taken

Configure Proxmox
The default installation creates a dedicated management interface so we need to reconfigure Proxmox to bind the physical interfaces into a bond
The quickest way is to edit the /etc/network/interfaces

cp /etc/network/interfaces /etc/network/interfaces.bak
nano /etc/network/interfaces

To load balance traffic, the recommendation is to use LACP, for example

auto lo
iface lo inet loopback

iface enp0s25 inet manual

iface enp7s0 inet manual

auto bond0
iface bond0 inet manual
	bond-slaves enp0s25 enp7s0
	bond-miimon 100
	bond-xmit-hash-policy layer2+3
	bond-mode 802.3ad

NOTE: If your switches support technology such as MLAG, you can connect the interfaces to different switches. Otherwise they need to be connected to the same switch

To support network redundancy, an example would be

auto lo  
iface lo inet loopback  

iface enp0s25 inet manual  

iface enp7s0 inet manual  

auto bond0  
iface bond0 inet manual  
	bond-slaves enp0s25 enp7s0
	bond-miimon 100
	bond-xmit-hash-policy layer2+3
	bond-mode 802.3ad
	bond-mode active-backup
	bond-primary enp0s25

Either way, we need to reconfigure Proxmox with a management VLAN interface and make the Linux bridge VLAN aware. For example, to use VLAN 100

auto vmbr0.100  
iface vmbr0.100 inet static  
	address 192.168.100.10/24
	gateway 192.168.100.254
       
auto vmbr0  
iface vmbr0 inet manual  
	bridge-ports bond0
	bridge-stp off
	bridge-fd 0
	bridge-vlan-aware yes
	bridge-vids 2-4092

Then we reboot Proxmox to make sure the changes are applied

Configure Switch
Because Proxmox is now doing VLAN tagging but the network switch is not, we cannot access Proxmox remotely anymore so we need to reconfigure the switch ports
We need to turn the port into a trunk port i.e. one which supports multiple VLANs and set the default, PVID or native VLAN to something unused
Once this is done, the switch will send VLAN tagged traffic to Proxmox and our connection will be restored
Add VLAN interfaces to Proxmox
Proxmox now has a VLAN aware bridge, so we can add VLAN interfaces to it for direct access to a storage VLAN for instance
To do this select the computer in the left hand pane, navigate to System | Network and from the Create drop down menu select Linux VLAN
Change the name to match the bridge and VLAN ID, for example for VLAN 200, we’d use vmbr0.200
Give the interface an IP address and mask, for example, 192.168.200.10/24
Then click Create
On the switch, update the port connected to Proxmox to allow this VLAN
Proxmox should now have access to other computers on your network in this VLAN
Assign VMs to VLANs
Because Proxmox and the switch are using VLAN tagging, virtual machines will need to support VLANs
For existing virtual machines, select the VM in the left hand pane then select Hardware
Click on the Network Device and click Edit
In the VLAN Tag field, enter the VLAN ID then click OK
On the switch, update the port connected to Proxmox to allow this VLAN
Repeat this for any other interfaces the VM has
For new VMs, add the VLAN tag as part of the installation process