Port is good if you use it, ZA Pro doesnt block I have Zone Alarm Pro (newest version 4.5) and it does not block port 5000. If you go to norton.com, as a part of their way to try to make you buy their internet security suite (just pick that you are a home user) they test your machine for open ports (do not think that its more extensive than BBand fast test but they seem to test different kind of ports rather than a high number, and theirs caught my open, BBand said I was safe). It found my 5000 port was open (click on advanced results). When I went to customize ZA (Firewall, internet zone/trusted zone, customize, (all the way down) block incoming/outgoing UDP/TCP ports and made it block port 5000 in both zone it still didn't work. I do not know if it is a good idea for me to block it, I am on a college network and use their printer. This is what the port seems to be created for, to use Plug and Play device attached to your network. Well actually this is my girl friend's computer and I do not want to block it and then get a phone call saying she cant print for some reason so I wont bother. If you are not in a situation like this, try blocking it, if it stops you from printing or using a device then open it, if you are set then keep it blocked, just remember that its blocked because in the future you might be trying to install something on a network and the blocked port might not let you.