IP Addressing 101

2013 is history and 2014 is here. Technology news will start to up here again very soon as the new year gets underway. In the meantime did you ever wonder about IP addresses and wanted to learn more about them? Well lets take this slow tech news moment to delve into the basics of IP addressing.

IP Addresses are critical to how our computers and mobile devices communicate.

IP addresses are unique sets of numbers assigned to devices that connect to a network. These sets of numbers are used to send and receive information on the network and to find other devices. An IP address is very much like a home address that others use to send you physical mail and for you to send mail from. Very simply IP addresses are unique identifiers of your location.

While your home or small business router usually handles all IP address assignments via a DHCP (Dynamic Host Control Protocol) server within the router's software, there are organizations that officially manage and allocate blocks of IP addresses for companies and organizations, just like we do at the Borough of West Chester's local area network (LAN). IANA (Internet Assigned Number Authority) handles IP addresses allocated globally, typically to Regional Internet Registries. In the Unites States, IP address allocation is managed by ARIN (American Registry for Internet Numbers).

To see what I am talking about check this out and follow along. Be warned - this is very exciting.

IP addresses are represented as a set of dotted decimal numbers. Check it out for yourself and click on the Start button. In the "Search" or "Run" field type in CMD. At the command prompt (which is the C:\>) Type in ipconfig /all followed by the Enter key.

You will see a screen that looks just like the one below (although you may see different numbers) and the yellow highlighted box is merely for this article:

Look at the area in the yellow box. Look for the line IPv4 address. You will see the numbers 192.168.1.4. This is the IP address that my wireless router is assigning to my computer which is connected wirelessly to the router.

This address is used by every other device I have connected on my home network to communicate with my computer.

Look back at the image above. You will see a line that shows my subnet mask is 255.255.255.0.

What does this mean?

Subnets divide networks into groups. You may want to create different groups within a network for giving different users access to different resources, for performance optimization, or for security reasons. Subnet masks tell other devices if a specific device is on a local or remote network, to efficiently route packets.

Another glance back at the image and you will see my gateway address is 192.168.1.1. In most small business and home networks, the gateway address is typically the IP address assigned to the router. The gateway acts almost like a traffic cop, managing the flow of traffic between the Internet and the LAN.

You can learn more about IP Addressing here.