I have recently set up a small domain consisting of a DC and RDS server. There is also a webserver in a DMZ which talks to a SQL Express database on the DC.
Whilst setting up all of this I have disabled the windows firewall on the DC and RDS servers. I would now like to enable these firewalls to allow only what is needed.
I have always been a little unsure how to setup the windows firewalls. Is there an easy way to see what ports etc need to be left open.
The servers are now in use so I don't really want to start closing ports risking stopping the servers working as they should.