I use 'Shields up' at click here to test my firewall (Zone Alarm Pro). Recently it has started showing that port 113 is open. This is what it said:
Identification/Authorization Service — Internet servers such as POP, IMAP, SMTP, and IRC query this port in response to client connections. It should NEVER be open since this is a source of tremendous information escape. Unsophisticated firewalls will show it closed — thus this provides a means for intruders to detect an otherwise stealthed computer. Only the latest, highest technology, adaptive firewalls are smart enough to stealth this port against random probes while showing it closed to queries from valid servers.
It's scary reading and I was wondering how to close this port. I don't have and IRC program running and I've shut down both 'Outlook' and 'Mailwasher' but that doesn't work. Nowhere in Zone Alarm can I shut individual ports. Is there any way to shut this port?