VirtualBox troubles

[torhne]

I am losing my mind.
I have tried so many combinations of possibilities, that it is impossible that I havent stumbled on the correct solution.

I have a Dell poweredge T420 Server. Bunch of Nics in it, disabled ALL but the onboard nics, and uplugged everything BUT the WAN cat6, from the modem.

No matter what I do, I cannot get it to get a DHCP4 address from WAN.
I cannot reach it on any internal ip, bridge, virtual internal network from another machine, nothing. NOTHING.

I need help and feel like a failure for not being able to setup my home network. I dont get this.

[torhne]

Any ideas?

[Bonkerton]

I have set up OPNsense on VirtualBox for testing purposes,
assigned WAN IP from my own Router,
but never tried to get WAN IP directly from a cable-modem or whatever your access to ISP is

For testing I set up a Linux VM to be on the same internal network as the OPNsense VM LAN port,
so I was able to access it from there and get a better view of what's happening.

Would this be any help
https://kifarunix.com/how-to-install-opnsense-on-virtualbox/