Intro

In my previous post, I've set up a PoC to validate the possibility to create a cluster of 2 OPNsense VMs in Proxmox VE and make the firewall highly available.

This time, I will cover the creation of my future OPNsense cluster from scratch, plan the cut over and finally migrate from my current physical box.

Build the Foundation

For the real thing, I'll have to connect the WAN, coming from my ISP box, to my main switch. For that I have to add a VLAN to transport this flow to my Proxmox nodes.

UniFi

The first thing I do is to configure my layer 2 network which is managed by UniFi. There I need to create two VLANs:

• WAN (20): transport the WAN between my ISP box and my Proxmox nodes.
• pfSync (44), communication between my OPNsense nodes.

In the UniFi controller, in Settings > Networks, I add a New Virtual Network. I name it WAN and give it the VLAN ID 20:

I do the same thing again for the pfSync VLAN with the VLAN ID 44.

I will plug my ISP box on the port 15 of my switch, which is disabled for now. I set it as active, set the native VLAN on the newly created one WAN (20) and disable trunking:

Once this setting applied, I make sure that only the ports where are connected my Proxmox nodes propagate these VLAN on their trunk.

We are done with UniFi configuration.

Proxmox SDN

Now that the VLAN can reach my nodes, I want to handle it in the Proxmox SDN.

In Datacenter > SDN > VNets, I create a new VNet, name it vlan20 to follow my own naming convention, give it the WAN alias and use the tag (ID) 20:

I also create the vlan44 for the pfSync VLAN, then I apply this configuration and we are done with the SDN.

Create the VMs

Now that the VLAN configuration is done, I can start buiding my VMs.

This time I already have the ISO uploaded