old laptop into firewall

Hi,

I have old laptop that I like to use as firewall (home license - v9).

It only has one ethernet port. If I get USB to Ethernet adapter, is that going to work?


Also, I was just playing with it and I tried installing v8 and it says it found one ethernet port. But when Installed v9, it says it cannot find any network port. Any reason for that?


What do you recommend I should buy to add extra ethernet ports?

thanks


Samir