I ran a network scan on my Aironet 1130AG wireless access point and I discovered that udp port 27015 was open.  Apparently this is a port that half-life uses for online gaming.  I looked everywhere in the AP configuration and docs and I can't figure out how this port was opened.  I can filter the port with an access-list but I really want to know why this port is opened in the first place.  Does anyone have any ideas?  Thanks for the help.