There comes a time in every geek’s life when they need to know their IP address. If you are one of those people, read on for instructions on how to find yours.
Introduction to IP Addresses
Every computer connected to a network is assigned a unique identifier. That identifier is known as an internet protocol address, or IP address for short. I like to think of IP addresses as phone numbers for computers.
Without diving too deeply into the realm of networking, there are two IP addresses that the average user may need to know at some point. The first is their external IP address, which is the IP address that users from other networks or the Internet utilize to find your local network. And the other is your local IP address which is how devices on your local network communicate to each other.
If you are away from your network and want to “contact” your network, or computer connected to it, you will need to know its external IP address. If you want to “contact” a device on the same network as you, you will need to know its local IP address. Below, I explain how to find out both, beginning with the easiest, your external IP address.
Find Your External IP Address
This one is easy. On any device on your network, open up a web browser and visit http://whatismyip.com. It will tell you in big bold font what your external IP address is.
Find Your Local IP Address
Go to the computer whose local IP address you wish to know. Determine what operating system it is running, and scroll down to the appropriate section below for instructions on how to find the IP address.
There are a few ways to find your local IP address on Microsoft Windows, but only one method is consistent across all the recent versions of Windows. Because of the discrepancies between versions, I will detail this method, even though it not necessarily the easiest one.
You need to run the “ipconfig” command from a command prompt. To do that, hit the key combination of “Ctrl + r” on your keyboard. This should open up a window titled “Run.” In this run dialog window, in the text field, type “cmd” and then hit Enter. A black command prompt window should open. In that command prompt, type “ipconfig” and hit Enter again. Buried in the output from that command is the local IP address of your computer.
To find it, look in each section of the output from that command for a line that says “IPv4 Address.” Once you have found it, your local IP address should be the series of period-separated numbers next to it. For example, at the moment, mine is “192.168.0.107.”
Mac OS X
For Mac OS X, the easiest method that is consistent across recent versions is to look under “Network” in “System Preferences.” To do this, click the apple pull down menu, and choose “System Preferences… ” Now find the Network entry and click it. A window should appear detailing a bunch of information; you want the IP address. For example, mine is 10.0.2.15 in the screenshot below.
In Linux operating systems, the method consistent across the most distributions is to run the ifconfig | grep 'inet addr' command with root privileges on the command line. Depending on your setup, your computer may boot into a command line, or it may boot into a user interface such as KDE or Unity. If you start into a user interface, you will want to open a terminal window (you will need to Google how to do this as the precise methods vary across distributions and user interfaces). Once at a command line, run “ifconfig” with elevated privileges. For many distributions, this is as simple as typing sudo ifconfig | grep 'inet addr', and typing in your password. For others, you will need to switch to the root user with the “su” command, and then run the ifconfig | grep 'inet addr' command.
Once “ifconfig” is run, you must read through each line of the output to find your local IP address. You are looking for the line that begins like this: “inet addr: 192.168.” On many computers, that will probably be the first line. Once the line is located, your local IP address is the period separated group of numbers next to “inet addr.” For example, in the screenshot below, mine is 192.168.0.175.
And that’s it! You now have your local IP address.