Console commands, mobo/cpu/mem info
dmidecode and /proc/cpuinfo etc don't work in the shell.
I would like to know which motherboard is in the actual server since I don't want to shutdown the firewall.
Anybody know if this is possible with a certain command or package?
It isn't practical to identify the motherboard by running commands in the OS. The best you can achieve is a list of the devices identified, and then use that list to compare against the spec of motherboards you think it might be, until you find a number of matches - and then guess which one it might me ;)
The only realistic option is to pop open the case (you may be able to do that while it's running) and look.