I have a simple setup:
My PC: 192.168.1.1
Proxmox: 192.168.1.253 (enp11s0)
pfSense (VM under Proxmox): 192.168.1.254 (enp5s0)
From my PC I can access pfSense just fine, however, NOT proxmox.
I can't even ping Proxmox from my PC, nor from pfSense.
/etc/network/interfaces:
auto lo
iface lo...