IP Addresses

About IP Addresses
What's My Public/External/Internet IP Address?
Private/Internal IP Address, For Linux Users
Private/Internal IP Address, For MS Windows Users

 

About IP Addresses

Your IP address is a number that identifies your computer on a network, including the internet, and any local network your computer might be connected to.  For internal purposes, the "loopback address" of every machine is 127.0.0.1.  And on smaller private networks, there might be only one machine (called the "gateway", which might just be a router) with an external internet IP address, while the rest of the machines on that network can be accessed by a private internal IP address of the form 192.168.x.x or 10.x.x.x, where the x can be any number from 0 to 255.  Such private IP addresses can't be accessed directly from the internet; all communication to/from them must go through the gateway.  Every computer that's directly connected to the public internet gets an IP address that is unique, meaning that no other computer on the internet has the same IP address at the same time.

 

What's My IP Address? (Public/External/Internet)

54.205.179.155

Your IP Address is: 54.205.179.155
Your hostname is: ec2-54-205-179-155.compute-1.amazonaws.com

If you're looking for your IP address, you probably want your external internet IP address, the number that identifies you on the internet.  To determine this address, you might need to ask a source that's external to your network, like a website.  This is probably the easiest and most reliable way of discovering your IP address.  In addition to this page, which shows your IP address and hostname just above this paragraph, these other webpages will also tell you:

www.whatismyipaddress.com
grc.com/default.htm (click "Shields Up!", then "Test My Shields")
www.junkbusters.com/cgi-bin/privacy (towards the middle of the page)
noc.auburn.edu/

Finally, you can search google for the phrase "your ip address is" (in quotes), and you'll find lots of websites that tell you.

 

Private/Internal IP Address, Linux users:

Click here to learn how to find/set the IP address on your system.

 

Private/Internal IP Address, MS Windows users:

On Microsoft Windows, your private/internal IP address can be found by clicking Start, then Run, and then typing winipcfg if you're running Windows 95/98/ME, or ipconfig if you're running Windows NT/2000/XP.  This should pop up a window that might list a few different IP addresses.  Another way to tell is to run the netstat command (available on some Windows systems), and read the entries that say "name:number" under "Local Address."  The name listed there is your computer's name, so you can then type ping name and it will show you your own IP address.

Note that if you are NOT connected to the internet through a router, but instead have a dial-up connection, or a cable/DSL connection that's connected directly to your computer, then this internal IP address will be the same as your public internet IP address.