You know how to change port numbers? Port forwarding is an area where people are most confused. The reason, in my opinion, is that each manufacturer of the router has their own different way of doing so. If you have router in your house or at workplace then change port numbers is a necessary. What it does is open a specific port to a specific computer. The port typically requires opening certain software applications. The most common application is remote access.

Here is a step by step guide to change port numbers:

1. Write the IP address of your router in your browser. If you do not know, here's a tip for finding the ip address. Go to "Start" then click on "Run", now type "CMD". A DOS window will open, in that window write "IPCONFIG". See the list and you will find your IP address for your computer, the subnet mask and default gateway. The default gateway is usually your router's IP address.

2. Now go to the login page of your router. If you have never changed the default (most people do not) here are the common name of the default user and password:

admin password
administrator password
admin admin
"admin blank"

3. Once you are connected, you need to use settings for port forwarding. This is where each manufacturer does their own way. Basically you are looking for menu adjustment "The applications and games" or "firewall"

4. Once you are there, you will need to enter the port of departure and arrival range, be it a TCP or UDP port, the name you want to give this parameter and the address computer's IP you forward the port. Make sure you apply the boxes are checked and save it.

For instructions specific to your particular router please check with your manufacturer. Here are some common ports for certain applications (All are TCP unless otherwise noted):

VPN 1723
Remote Desktop 3389
VNC 5900
FTP 21 Only if you run your own FTP server
PCAnywhere TCP 5631 UDP 5632