I am trying to learn how to set up an RB750GL. I have just upgraded it to latest firmware and the default setup puts ether2-5 in the default bridge. And this obviously connects to ether1 which allows internet connection. That works ok for me.

If I remove ether5 from that bridge, with the aim of creating a DMZ for a small server, I am mystified as to how ether5 can get an internet connection.
Do I create a 2nd bridge with ether5 in it (which I have tried and it fails to get to the internet), or is there a different method?

cheers