Programs allow you to change the port for personal and possibly business security. All ports "act" the same. However, If I know that you have pcAnywhere installed on your computer and waiting for a user to remote control your computer then I'd know that the default ports for pcAnywhere are 5631 and 5632 and all I would need is an external IP address for your network and I could do some damage to your computer and/or Local Network. If you install a program that allows you to change the default port it uses, by all means.....change it. You have up to 65,000+ ports you can use.