There is a couple ways to find which ports the programs are useing.
While the program in running on his machine go to command prompt and write "netstat /a" this will show all ports being used by what programs on his machine.(This has to be done on his machine) Or you can do a google search for the ports the program uses. Then once you find what ports it uses, unless it changes every time, go into your fire wall and block all ports you don't want to be used by him or her.
You can also find the port numbers by net sniffing. Or what he said above. If your fire_wall/router/etc.. has a log then you can see that( That is if it records the right information).
http://www.plevna.f9.co.uk/blockkazaa.htmQuote: "
Some sources say that peer-to-peer file sharing programs like LimeWire and KaZaA use a variety of ports including ports 1214 outbound and ports 1214-8000 inbound. To block LimeWire ports you would also have to block TCP port 6346 and stop UDP port 6346. However, there is a post in a forum which infers that the user can choose the port which LimeWire uses. See the LimeWire program's menus - Tools -> Options -> Advanced -> Firewall Config
It is now generally accepted that if you block access to those ports, file sharing applications like LimeWire will hop from port to port until they find an unblocked one, and will even use port 80.
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http://www.pcquest.com/content/p2p/102091201.asp
Quote: "
The P2P apps, which use the Gnutella network connect to peers on ports 6346 and 6347. We tried to block two such apps—Morpheus and Limewire. To do so, in the BBIagent Access Control section, as mentioned above, keep everything the same and enter 6346-6347 for the Service ports, and TCP for Protocol. Click on the Insert button to enable the rule. Create a similar rule for UDP traffic.
This method worked for us, but the peer ports may change if future updates for these apps come out. Also, some P2P apps may change their network/protocol—for example Morpheus worked on the FastTrack network earlier.
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