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/14-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 in the list, here cerbere-head1 with ID 122. Then in the tooltip I can define the maximum of restart and relocate, I keep Failback enabled and the requested state to started:

The Proxmox cluster will now make sure this VM is started. I do the same for the other OPNsense VM, cerbere-head2.

HA Affinity Rules

Great, but I don't want them on the same node. This is when the new feature HA affinity rules, of Proxmox VE 9, come in. Proxmox allows to create node affinity and resource affinity rules. I don't mind on which node they run, but I don't want them together. I need a resource affinity rule.

In Datacenter > HA > Affinity Rules, I add a new HA resource affinity rule. I select both VMs and pick the option Keep Separate:

✅ My OPNsense VMs are now fully ready!

TODO

Check conso Watt average: moyenne 85W Check temp average (midnight): ~33°

Switch

Backup OPNsense box

On my physical OPNsense instance, in System > Configuration > Backups

Disable DHCP on OPNsene box

In Services > ISC DHCPv4, and for all my interfaces, I disable the DHCP server.

Change OPNsense box IPs

In Interfaces, I the IP of each interfaces from .1 to .253 As soon as I click on Apply, I lost the communication, which is expected

Change VIP on VM

On my Master VM, In Interfaces > Virtual IPs > Settings, I change the VIP address for all interface Then I click Apply

Remove GW on VM

In - # System: Gateways: Configuration, I disable the LAN_GW which is not needed anymore

Configure DHCP on both instance

In both VM, in - # Services: Dnsmasq DNS & DHCP, I enable the service

Enable DHCP on VM

Enable mdns repeate In - # Services: mDNS Repeater, I enable and enable CARP Failover

Replicate configuration on VM

In - # System: High Availability: Status, Synchronize and reconfigure all

In my rack, I Unplug OPNsense box WAN

Plug WAN on port 15

Verify

Ping VIP OK Vérifier interface OK tests locaux (ssh, ping) OK

Basic (dhcp, dns, internet) DHCP OK -> Restart Unbound service DNS NOK Internet OK

Firewall -> Need some not critical opening All sites -> OK mDNS (chromecast) -> OK VPN -> OK TV -> OK

Vérifier tous les devices -> OK

DNS blocklist

Check load (ram, cpu) -> OK

Failover

In - # System: High Availability: Status, Synchronize and reconfigure all In Every domains (reverse proxy/layer 4 proxy) give this error: SSL_ERROR_INTERNAL_ERROR_ALERT Anything else works apparently fine (to confirm)

Test proxmox full shutdown

Clean Up

Shutdown OPNsense Check watt Check temp

Rollback