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 Yes and no. IP addresses are unique addresses of network adapters that are used to identify computers on a network - and the Internet is one vast network. Most Web sites capture a variety of information about site visitors including browser type, operating system, and IP address.

An IP address is a string of numbers that don’t mean much to the average computer user. However, if you know what each set of numbers means, you’ll find a wealth of information. An earlier post discusses exactly what an IP address is and what the various numbers indicate.

For example, specific prefixes are assigned to ISPs, companies, and other organizations. By looking at a user’s IP address, you may be able to determine that the user is on a particular college campus.

Tools are readily available on the Internet that allow you to discover your own IP address. Some of these tools even pinpoint your community - complete with maps! In theory, anyone who can view your IP address can figure out your general location. People with access to your IP address can also learn who your Internet Service Provider is based on this information. While this information doesn’t pinpoint your location down to your exact physical address, it does reveal more than you may have realized.

For example, I just ran an “IP trace” on my own computer. This trace reported:

• My IP address
• My country, region, and city
• My latitude and longitude
• My Internet Service Provider
• IP protocol
• Remote port
• Connection type
• Browser
• Operating system
• Language
• Support for plug-ins
• And more. . .

If a crime is suspected or some other legal concern, it’s conceivable that law enforcement officials could go to the ISP and ask them to identify you.

While I have no intention of doing anything illegal, I’m not sure that I want this much information about me or my computer readily available to marketers and hackers. In addition, did you know that there is such a thing as a reverse IP search? Subscribers to massive databases can enter an IP address and find out who you are!

For example, Web sites can discover your IP address and link it to other, personally identifying information that you’ve provided them with during your visit. Let’s say you place an order with a Web site. Not only will the Web site have your IP address, they will have your name, address, phone number, and credit card information as well as your product preferences. If the Web site has “partners,” your information may be shared with, or even sold to, other marketers and database builders.

A variety of tools are available for hiding IP addresses including proxy servers and software packages that hide your IP address.

Of all the billions of computers connected to the Internet, each one has a unique, identifying number assigned to it called an IP address. These numbers are based on combinations of binary numbers (0 and 1) grouped into “octets.” While the binary IP address form contains four groups of eight digits with only 0s and 1s (such as 01010101. 01010101. 01010101. 01010101), the IP address that you actually see is expressed in a dotted decimal format (such as 255.255.255.255).

The dotted decimal format makes it easier for humans to work with these long binary numbers.

When you think about all those 0s and 1s, it becomes almost mindboggling. Over 4.3 billion combinations are available using the four octets.

But these numbers aren’t just random, IP address octets are broken down into “Net” and “Host” (also called “node) octets. This is known and subnetting. For example, the first set of numbers belongs to the Net section which is used to identify which network the computer belongs to. The Host section identifies the computer itself with the last octet always being included in this section.

Some IP addresses are reserved for special purposes based on an organization’s size and need. These include the following classes and addresses:

• 0.0.0.0 - The Default Network
• 1 - 126 (first octet represents the Net identifier) - Class A IP addresses are used for large organizations and account for half of all total available IP addresses.
• 127.0.0.1 - The Loopback Address (often used in troubleshooting. This address is used by host computers to send messages back to itself
• 128 - 191 (first and second octet included in the Net identifier) - Class B IP addresses are typically used for medium-sized networks such as college campuses. These IP addresses account for about one quarter of all available IP addresses.
• 192-223 (first, second and third octet included in the Net identifier) - Class C IP addresses are used for smaller networks
• 224 (first octet represents the Net identifier) - Class D IP addresses are used for multicasts
• 255.255.255.255 - Broadcast IP addresses are used for sending messages to all computers on a network
• Experimental IP addresses are Class E addresses

Think that 4.3 billion IP addresses aren’t enough? As the Internet continues to grow, there’s a good chance that 4.3 billion IP addresses won’t be enough. That’s why a new IP version 6 protocol has been designed to accommodate 128 bits (instead of 8) grouping.

Depending on your network (home, corporate, or Internet), you may run into several instances where you must deal with IP addresses. For example, on a home network, your router and each computer on your system as well as connected devices such as network printers will each have an IP address such as 0.0.0.1, 0.0.0.2, and so on. Each device on your own network will have a unique IP address in relation to your individual network. Your neighbor’s home network may use similar, if not identical IP addresses.