Fax Problems

How do I close a specific TCP port:
To close a port, it's usually only necessary to shut down the program holding the port open. On some ports it's enough to tell the program or service that the port should not be opened. A good example is the Microsoft Internet Information Services in Windows 2000 and Windows XP. If installed, they open three ports automatically: 21, 25 and 80. Port 21 is the FTP server, port 25 the SMTP server (email server) and port 80 the webserver for http.

Here's how we find out what processes are keeping those ports open:

1. Hit windows key + r (or click start --> run)
2. Type 'cmd' (without the quotes)
3. Press enter (or click 'ok')
4. Type 'netstat -ano' (without the quotes)
5. Press enter

This lists all ports, the IP addresses using them, and more importantly, the Process IDentifier (PID) that has them open. Find any listings of the ports you specified, and make a note of the PID. Now, follow these steps:

1. Hit ctrl + shift + esc
2. From the 'View' menu, select 'Select Columns'
3. Check the box next to 'Process Identifier'
4. Press 'ok'

Now, Task manager will show you all the processes running on your machine, and the PID of each. Find the ones you noted earlier, and stop them. This is typically all you need to do!