Finding Someones IP Address

Every computer, smart phone or other device connected to the internet has a unique number known as an Internet Protocol (IP) address. IP addresses contain four sets of numbers separated by periods and look something like 71.14.68.312. Each number is different based on the location of your computer. If you are accessing the internet from both a laptop and a desktop computer at home, the IP address will be the same for both machines. Most internet service providers, ISP’s, are issued a block of IP addresses for their customers. If you and your friend both live in the same region of the country and both use the same ISP, chances are your IP addresses are very similar. You may wonder if someone can find out your identity by knowing your IP address. This is not likely, at least not without a subpoena. Typically, all someone can easily learn about you from knowing your IP address is the ISP that you use and maybe the state and city where you live. You can quickly find out your IP by visiting any number of websites designed for this purpose. WhatismyIPaddress.com or ip-adress.com or ipaddresslocation.org are just a few of the sites dedicated to telling you your IP address quickly. This method will tell you your own IP address, but what if you want to find out someone else’s IP address? There are a few easy ways to do this as well.

 

Step 1: Locate the IP address of someone who sent you an email by checking their email header. Most email headers are hidden from view, but your email client should have a way for you to make it visible. Email headers are always delivered with every email, so check with your email client for display options if you can’t see the headers. For example, if you are using outlook express, open the message and go to the File menu. Select Properties > Details > Message Source, then copy and paste the message source into a new message. If you use AOL as your email client, open the message and click “Details” in the top portion of the email, directly underneath the “To” line. You are looking for a line that begins “Received: from sally.aol.com (74.54.246.39)”. If you only see one “Received.from” line, the grouping of four sets of numbers in parentheses is the sender’s IP address.

 Sometimes you will see more than one ‘Received.from” line, which means that your email went through multiple email servers or a spammer is trying to confuse things and hide their IP address. If you have more than one “Received.from” line in an email sent by someone you know, it is most likely that the last “Received.from” line in the header contains the IP address of the sender. If fake information has been inserted by a spammer, you will need to take a few extra steps to find their real IP address. Start from the last "Received: from" line and trace the message path up through the header. The location listed as “by” in each "Received" header should match the next "from" location listed in the following "Received" header. Ignore any entries that contain IP addresses or domain names that do not match up with the rest of the header chain. The last "Received: from" line with valid information is the line with the sender's true address.

 

Step 2:  Sometimes the email client you use will not display IP addresses in the headers out of respect for their user’s privacy. Gmail is one such web based email client that protects its users. In this case, you can find someone’s IP address by knowing their DNS address. DNS stands for Domain Name Server and if you know someone’s domain, it is possible to trace their IP address. Domain names are easier to remember and you can easily find a free service to translate the domain name you enter into an IP address. If you want to find an IP address from a domain name, you must enter the domain without the http:// prefix. This will not work for an individual’s IP address unless they own the domain.

Step 3: If you own a domain name, here is another way to discover someone’s IP address. Tell the person about a URL on the site that you know does not exist, like
http ://www. yourdomainname.tv/makeitup. jpg. If they visit the page, they'll get a "404 error". You can then search the log for ‘makeitup.jpg’ and the only IP address that shows up will be theirs. Once you have the IP address, go to any of the sites online that trace the addresses and enter the number. You will receive basic location information. This is especially useful if you are being harassed by someone using IM’s. Once you have their general location, ask them how the weather is there and they will likely leave you alone. Conversely, you should never click a link or visit a site that you think is suspect. This method could just as easily be turned around and used on you by unscrupulous people.

Step 4: You can also find IP addresses by using netstat if you are running Windows. Open a command window (Start > Run > cmd) and type netstat. With netstat, you can see the active connections of your computer. Netstat has options to show either names or addresses, and you can set up an interval to refresh, so that it checks and shows connections every 10 seconds, or whatever you prefer. In order for netstat to be effective, you must have an active connection with another computer, like when you transfer files or exchange software or music. Once you open the command and type in netstat, it will show the connected computer’s IP address as well as the TCP port it is using to communicate with your computer.

 

Finding someone’s IP address is not rocket science, but once you have it, there is not much you can do with it without a subpoena. If you are being harassed, as in Step 3, just letting the person know what city they live in may be enough to make them think twice about bothering you again. There are other ways to find IP addresses such as IP sniffers, software you can purchase, or programs you can write.