Intro

In my previous [post]({{< ref "post/12-opnsense-virtualization-highly-available" >}}), 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 the virtual machines on Proxmox.

The first VM is named cerbere-head1 (I didn't tell you? My current firewall is named cerbere, it makes even more sense now!) Here are the settings:

• OS type: Linux
• Machine type: q35
• BIOS: OVMF (UEFI)
• Disk: 20 GiB on Ceph distributed storage
• RAM: 4 GiB RAM, ballooning disabled
• CPU: 2 vCPU
• NICs:
  1. vmbr0 (Mgmt)
  2. vlan20 (WAN)
  3. vlan13 (User)
  4. vlan37 (IoT)
  5. vlan44 (pfSync)
  6. vlan55 (DMZ)
  7. vlan66 (Lab)

ℹ️ Now I clone that VM to create cerbere-head2, then I proceed with OPNsense installation. I don't want to go into much details about OPNsense installation, I already documented it in a previous [post]({{< ref "post/12-opnsense-virtualization-highly-available" >}}).

After the installation of both OPNsense instances, I give to each of them their IP in the Mgmt network:

• cerbere-head1: 192.168.88.2/24
• cerbere-head2: 192.168.88.3/24

While these routers are not managing the networks, I give them my current OPNsense routeur as gateway (192.168.88.1) to allow me to reach them from my laptop in another VLAN.

Configure OPNsense

Initially, I thought about restoring my current OPNsense configuration and adapt it to the setup.

Then I decided to start over to document and share it. This part was getting so long that I prefered create a dedicated post instead.

📖 You can find the details of the full OPNsense configuration in that [article]({{< ref "post/13-opnsense-full-configuration" >}}), covering HA, DNS, DHCP, VPN and reverse proxy.

Proxmox VM High Availability

Resources (VM or LXC) in Proxmox VE can be tagged as highly available, let see how to set it up.

Proxmox HA Requirements

First, your Proxmox cluster must allow it. There are some requirements:

• At least 3 nodes to have quorum
• Shared storage for your resources
• Time synchronized
• Reliable network

A fencing mechanism must be enabled. Fencing is the process of isolating a failed cluster node to ensure it no longer accesses shared resources. This prevents split-brain situations and allows Proxmox HA to safely restart affected VMs on healthy nodes. By default, it is using Linux software watchdog, softdog, good enough for me.

In Proxmox VE 8, It was possible to create HA groups, depending of their resources, locations, etc. This has been replaced, in Proxmox VE 9, by HA affinity rules. This is actually the main reason behind my Proxmox VE cluster upgrade, which I've detailed in that [post]({{< ref "post/proxmox-cluster-upgrade-8-to-9-ceph" >}}).

Configure VM HA

The Proxmox cluster is able to provide HA for the resources, but you need to define the rules.

In Datacenter > HA, you can see the status and manage the resources. In the Resources panel I click on Add. I need to pick the resource to configure as HA. Then in the tooltip I can define the maximum of restart and relocate, pick a group if needed, then select started:

My Proxmox cluster will now make sure my VMs are started, but I don't want them on the same node. If this one fails, I will be sad.

Proxmox allows to create node affinity rules and resource affinity as well. I don't mind on which node they run, but not together. I need a resource affinity rule.

In my current Proxmox VE version (8.3.2), I can't create affinity rules from the WebGUI. I have to use the CLI to achieve that. From any node of the cluster, I create the resource affinity rule in /etc/pve/ha/rules.cfg:

 ha-manager rules add resource-affinity opnsense-cluster \
 --affinity negative \
 --resources vm:122,vm:123       

TODO

HA in proxmox Make sure VM start at proxmox boot Check conso Watt average Check temp average

Switch

Backup OPNsense box Disable DHCP on OPNsene box Change OPNsense box IPs

Remove GW on VM Configure DHCP on both instance Enable DHCP on VM Change VIP on VM Replicate configuration on VM Unplug OPNsense box WAN Plug WAN on port 15

Verify

Ping VIP Vérifier interface tests locaux (ssh, ping)

Basic (dhcp, dns, internet) Firewall All sites mDNS (chromecast) VPN TV

Vérifier tous les devices

DNS blocklist

Check load (ram, cpu) Failover

Test proxmox full shutdown

Clean Up

Shutdown OPNsense Check watt Check temp

Rollback