As you’re wandering around the Internet, a pop-under appears – ‘You’re IP address is available to everyone! Click here for better security!’ Scared, you click, only to be pitched something you aren’t really sure you need. Is your IP address revealing too much about you?
The simple answer is that the IP address is your return address, so yes, it is revealing a great deal. Like a return address on an envelope, your IP address tells everyone where the message originated. And like an envelope’s address, it is visible for all to see.
There are a wide variety of Internet messages, but the majority of useful ones are of the form ‘please send me the following’. You (actually your browser) asks for HTML pages, images, text and program files, and so on, and in each case, you need a return address so the other end knows where to send it.
Obviously, with this much traffic, everyone’s return address is less important than it would seem at first. As well, it is somewhat cryptic: 192.168.0.1 is a typical IP address, and says nothing about whom it belongs to, or where they live exactly.
Adding to that is that the majority of people still have dynamic IP addresses. Your Service Provider has a pool of addresses that they need to reuse (there’s a limited number of these addresses), so when you dial in, you get the next available one they have. When your connection is less dynamic (such as a cable modem) you might get a fixed one (called a static IP), but even that can change over time.
Everyone has them, they don’t reveal anything about you – so then there’s nothing to worry about, right? Unfortunately, no. While you are on the Internet, your address points back to you. If your computer is not set up securely, it can let someone get inside, with possibly disastrous effects.
Remember that data you asked for, and gave your return address to? Your computer needs to peek onto the Internet to see that returning information (similar to Fido waiting for the mailman). However, some computers peek too much, and not only pay attention to returning mail, but requests from outside that they shouldn’t (such as ‘let me look inside your computer’).
One great site to check if your computer is too ‘free and easy’ is Gibson’s Research Corporation, and their ShieldsUp! Test (http://www.grc.com/default.htm). It will walk you through the testing, and show you the result. It’s also an education into how the Internet can attack you.
All this should serve as a reminder to keep your system secure. Buy a software or hardware firewall, and pay attention to your Operating System’s Security Bulletins.
So while your IP address doesn’t open the door to computer invasions, it does provide a return address to others – your diligence makes sure they don’t get a welcome, too.