VLAN Trunking and Proxmox Clusters (Day 33)

Following the post systemd-and-proxmox-day-3, I eventually declustered my Proxmox nodes. Now with the addition of a new MinisForum MS01, I did some rebuilding and went back to Proxmox clusters.

The current setup includes both PCs in a cluster, deliberately excluding the OPNsense Proxmox node, with the main advantage of clustering being how easy VM migration is between nodes.

For this cluster, I decided to also try VLAN trunking on Proxmox, allowing a single NIC to handle multiple network segments. Here's how to set it up:

Step 1: Configure Proxmox's VLAN-aware bridge

Edit the network configuration by modifying /etc/network/interfaces:

auto vmbr0
iface vmbr0 inet static
        bridge-ports eno1
        bridge-stp off
        bridge-fd 0
        bridge-vlan-aware yes
        bridge-vids 2-4094

auto vmbr0.50 # Creates VLAN 50 interface
iface vmbr0.50 inet static
        address 192.168.50.240/24 # Your Proxmox IP 
        gateway 192.168.50.1

Step 2: Reboot Proxmox

After rebooting, note that you won't immediately regain access to Proxmox's web interface. This is expected behavior since the node now requires properly tagged VLAN 50 traffic.

Step 3: Configure your network switch

Set up the switch port connected to Proxmox as a trunk port, and configure it to carry all VLANs you plan to use with Proxmox and its VMs, with VLAN tagging enabled.

This allows the Proxmox host to receive properly tagged traffic for each network segment. The main advantage here is that each VM instance can operate on separate VLANs while using only a single physical port on your switch, reducing the number of switch ports needed.