For IT Pros This page contains information about the "Mostly Closed" campus firewall group.
The Mostly Closed group is designed for web or email servers, allowing access to those services without being fully exposed to the Internet. It can be too permissive for some desktop systems, and can be too restrictive for other types of servers.
Only HTTP, HTTPS, IMAP, secure IMAP, POP3, secure POP, FTP, SFTP, SMTP, and H.323. (A specific port list is available.)
Assuming that a machine uses the standard ports for its services, placement in this group means that users from outside the firewall will be allowed to initiate connections with encrypted and unencrypted web servers, mail servers, FTP sessions, and voice-over-IP connections on machines in this group. No other services will be accessible to outside users if a machine is in this group.
All (except the ports that are always blocked in both directions)