Finding Your Public IP with Telnet (CLI)

Her I’m going to show you a little trick off a way to get you public IP when you just have a command line interface.

This can be done in any equipment with telnet like a:

• Router
• Switch
• Linux Server
• etc

 

How To Do It – Site: Check IP

The webpage:

• http://checkip.dyndns.org

gives out you public IP on a Browser, so what we are going to do is to open the Web Page on the HTTP Port (Port 80), and get a response from the webpage with you Public IP.

This Web Page does not need you to send HTML to pretend that your telnet is a Web Browser (like the IP Echo Website bellow)

To do it:

telnet checkip.dyndns.org 80

or

telnet 216.146.38.70 80

if you don’t have DNS configured, and then do as soon as it connects press:

• ENTER (one or two times)

and it will give you the output bellow.

 

 

How To Do It – Site: IP Echo 

The webpage:

• http://ipecho.net

gives out you public IP on a Browser, so what we are going to do is to open the Web Page on the HTTP Port (Port 80), and then send some HTML code to pretend that your telnet is a Web Browser to get the HTML response from the webpage with you Public IP.

To do it:

telnet ipecho.net 80

or

telnet 146.255.36.1 80

if you don’t have DNS configured, and then paste the following HTML code

GET / HTTP/1.1
Host: ipecho.net
User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)

and press Enter, and you get this:

rigth here you can see you IP.

 

See Public IP on a Browser

In both methods/sites if you want, you can see the IP in a more pretty way, just copy the HTML code the Web Page returned (this output is from the IP Echo site):

to a text file with the “.html” extension in the computer you are using, I named mine index.html

save it and double click in the index.html which will open on your default browser, and show the HTML you copied from the command line: