Last Updated on September 21, 2020 by Jan Bachelor

Unless you opted for a PCI Passthrough method for your network cards (only recommended for advanced users), we will use the more standard and more widely used method of setting up two virtual switches in Proxmox, one for LAN and the other for WAN, and then assign network cards, accordingly.

1. Configure the LAN interface

• Under Datacenter -> proxmox, go to Network. Find vmbr0, which will contain the management port selected during the proxmox’s installation.
• Create an IPv4 range, e.g. 192.168.1.1/24
• Set up the IPv4 gateway to be the IP address of the OPNSense VM, e.g. 192.168.1.1
• Check that the LAN interface has an IPv4 and gateway addresses assigned (should be the starting number of the network that we will assign to OPNSense, not to Proxmox!).
• Edit the ‘bridge ports’ section and add additional ports that your server will use for the LAN (e.g. on a 6 port QOTOM, if we use port no.1 for WAN, this would be: enp2s0 enp3s0 enp4s0 enp5s0 enp6s0 (only space as a delimiter between pot numbers).
• Add a comment such as ‘LAN’ for future reference.

2. Configure the WAN interface

• Create a new Linux Bridge (e.g. vSwitch in ESXi terminology) .
• Assign the remaining WAN port to it, e.g. enp1s0 .
• Assign it an IPv4 address and a comment (no gateway to be specified since that is defined in the LAN bridge).

3. Final network configuration state

Below you can find an example overview of the ‘Network’ tab in Proxmox after the above was set up. Note that the virtual bridges are auto-started and so the inidividual ports do not need to be.

Finally, restart your Proxmox server for changes to take an effect.

Note: In case you get locked out, connect directly to the server (e.g. with QOTOM, an HDMI cable, keyboard and mouse) and use the command line interface in /etc/network/interfaces . After all, Proxmox runs on a standard Debian distro and so changes can be made there, directly, esp. in case of a lock out 🙂

Back to: Build Your Own Router – Proxmox, OPNSense, OpenVPN server and a VPN client all in one!