[TUTORIAL] Virtual Cold Spare for a Physical OPNsense Using Proxmox

[meyergru]

As some of you probably know, I often use virtual OPNsense installations under Proxmox in datacenters and there is a guide over on the OPNsense forum.

However, I found a new application for OPNsense under Proxmox as a cold spare, for which I wrote a guide, too.