I am not overly happy with my current firewall setup and looking into alternatives.
I previously was somewhat OK with OPNsense running on a small APU4, but I would like to upgrade from that and OPNsense feels like it is holding me back with it's convoluted web-ui and (for me at least) FreeBSD strangeness.
I tried setting up IPfire, but I can't get it to work reliably on hardware that runs OPNsense fine.
I thought about doing something custom but I don't really trust myself sufficiently to get the firewall stuff right on first try. Also for things like DHCP and port forwarding a nice easy web GUI is convenient.
So one idea came up to run a normal Linux distro on the firewall hardware and set up OPNsense in a VM on it. That way I guess I could keep a barebones OPNsense around for convenience, but be more flexible on how to use the hardware otherwise.
Am I assuming correctly that if I bind the VM to hardware network interfaces for WAN and LAN respectively it should behave and be similarly secure to a bare metal firewall?
Well I cant say specifically to your setup. But I have an old server that I use as a hypervisor running Proxmox. On it I have an OPNsense VM Ive been running for years now. I dont do any crazy pass thru stuff. I just added each NIC as a normal network device bridged to the specific hardware port. I also use it as a Reverse Proxy for all my internal service such as Emby.