I created an OPNSense VM in XenServer. One external network connection, one internal host-only, so OPNSense can route other VMs. The firewall refuses to allow anything over the internal NIC.
pfSense, installed in exactly the same manner, works.
Any idea if this is a bug, or if there is a configuration step I missed?
What means "refuse"? Packets get blocked and you see them blocked in log? Packets don't arrive at OPNsense? Internal NIC is assigned as LAN?
Assuming the other software was already installed and probably configured and running without issues:
Are you 100% sure OPNsense is configured correctly? Interfaces not reversed? Access permissions properly set? It sounds like a simple setup issue that would produce such a "fatal" problem.
Cheers,
Franco