Ever wonder what your IP address is? In most cases you could probably care less. But occasionally you may have a need to know how other computers see your system on the Internet, especially if you?re sitting behind a firewall. Most Corporate computer systems today are protected from direct access from the Internet by means of a firewall. A firewall is a piece of hardware, software or a combination of both that protects your computer systems from direct exposure to the outside world by hiding the actual IP addresses of the servers, workstations and other devices that are connected behind it. To the outside world, one or more IP addresses are exposed to the Internet, but none of the internal IP addresses are exposed. The firewall does the translation of the incoming and outgoing messages so that only the IP address(s) you want exposed will be.

There are several reasons for using a Firewall. The most obvious is for security reasons. It can help to protect the internal servers and workstations from direct attack by malicious users outside of your network. Another important reason for using a Firewall is for privacy purposes. This of course goes hand in hand with security. Most Firewalls contain internal rules that determine who can and cannot get into your network from the outside world.

There are times however, when you need to provide access to one or more of your internal systems to the outside world. An example would be where an external company provides an online service to your internal users by means of a web service or website. In order for your users to gain access to that external service or website, the IP address that your company exposes to the Internet may have to be added to the Firewall rules of the external service provider?s Firewall. On the other side of the equation, you may have to add the IP address of the external service provider into your Firewall. This will allow both networks to talk to each other.

In the event you ever need to know your external IP address, you can talk to your Network Administrator and/or Security Department. You may also visit one of the many websites that will tell you what your IP address is. Personally, I like this site:

http://whatismyipaddress.com/

When you visit the site, it will detect your IP address and display it to you. This address will be how others see you on the Internet.  This site also provide a useful feature that shows you where someone is physically located based upon their IP address.  This can be very useful in identifying the source of a malicious attacker.