Your computer has several different IP addresses that you can look up using different techniques.
Find Your Web IP Address
A variety of Web sites will detect your IP address and display it for you in an instant. In addition to showing you a number such as 126.96.36.199, these Web sites may also show you a map displaying your physical location or community. For example, I recently checked my IP address using such a site and was surprised to see a Google map showing my community.
The reason that an IP address can reveal your community is that Internet IP addresses are assigned to ISPs using a region-based system. By looking up the first set of numbers in your IP address, the Web site can then compare this number to database detailing ISP providers and their assignments. For example, I randomly created the IP address 188.8.131.52 for this article. I did a quick IP search and discovered that the ISP is AirTel Broadband in Bangalore, India.
While finding out IP addresses can give you a general idea of the location, these services aren't 100% accurate. It's not like they are going to pinpoint your exact address and reveal that information to anyone who happens to search. However, knowing that IP addresses can reveal your general location is a little alarming for those concerned about privacy.
Find your Router's IP Address
Depending on your router, the router will likely use a default IP address. For example, Linksys routers often default to 192.168.1.1 for the IP address. You should be able to find this information in the user's manual that came with your router. Similarly, you can visit the router's Web site and find out by searching the various support areas.
If you aren't having any luck or your system administrator has manually reconfigured the router's address, you can try "pinging" it. You can "ping" your router by going to the Command Prompt (Start > Programs> Accessories) and entering in a ping -r 1command followed by a website address. For example:
C:\ping -r 1 www.microsoft.com
This will send a ping to the Microsoft Web site, return a reply, and show the "route." The route IP address is your router's IP address.
All Other Physical IP and MAC Addresses
Your computer has a built-in utility that will list all of the various IP addresses that your computer, network adapters, and gateways use. Simply go to Start >Run> and type in: ipconfig /all (In Windows Vista, go to Start and type ipconfig /all directly into the Search bar and then click the program that shows up in the list or launch the Command Prompt and type ipconfig /all directly into the command line.)
This will launch the utility and list all IP and MAC addresses in use on your computer.