Hello,
I have hardware Firewall(Cisco ASA) installed between users and Exchange 2010 server. At this time I am trying to filter ports between users and server and left only ports which are required for server to operate. Users are using outlook to use mail service, and there is just one server. I was doing some research in internet and found that following ports are used: TCP/UDP 53,TCP/UDP 88,TCP 3268,TCP/UDP 389,TCP 80,TCP 443. These ports are opened from clients to server.
The problem is if only mentioned ports are opened between users and server, users are unable to use their outlook, it seems above list isn’t complete. Do you know which additional port numbers are required ?
Assuming the firewall working in statefull mode, does it requires to open some port for traffic that is originating from server to clients ?