Internal to External IP’s (From Anywhere)

Ok you take the time to set up the FTP server, you even made rules in your Router to allow access to Port 21 from the outside, so you think you are ready. Now you are in class and forgot your homework…you say EASY I’ll just log to my dorm computer via FTP and download it. The problem is you try to log in and its impossible.

What happened? Well for starters the IP you wrote on your arm before heading out to class has changed. Secondly unless you have a roommate who can text you the new ip we… you are screwed. So what do you do? Well i have devised a ruby executable with just a couple of lines of code that can help. It will tell you your external ip when you run it. You will need Ruby and RubyGems also rubyscript2exe more info on the web.

But how do i run it if i’m not on my computer well you can do what i do:

1) Get a program that will run scheduled events (you could use Windows own sheduler or if you want something better try Dazzling Events great app for many things).

2) Shedule the program to run every hour with a BAT file and when runned it will output the IP into a text file.

3) Send that text file (unencrypted/unencoded) to an emai. This can be done with BLAT. What email to use well you could use Gmail (you will need to create a tunnel with SSL) if you want SSL encryption or Bluebottle (easier). Now why would i want to email it if all i want is to see it?

4) Now the fun part comes. You have runned the app every hour and are able to send it via email, why don’t you just post it on a blog or SMS to your cellphone (data charges will apply so unless you have an unlimited data plan don’t try this). For the blog you can use Blogger, it will let you update a blog from an email account. For SMS ask your provider usually it’s something like (ie: That way you will be able to know your computers IP from anywhere in the world.

This has been the cheap way to do this, with some time and luck I’m sure you can find a way to do everything easier. But for now try it out. Hope you have fun and now that we are in the subject try checking your torrents from afar uTorrent has a webui that you can set up and check your downloads from any browser.

Here is the code for all this:

Ruby (External IP Finder, let’s call it “externalipfinder.exe”)

#!/usr/bin/env ruby
 require 'win32ole'
 require 'open-uri'
 echocmd = "IP: "
 ip = ( open("") {|f| /([0-9]{1,3}\.){3}[0-9]
puts echocmd + ip


Bat file (This is what you run every hour)

@Echo off
 SET password=yourpassword
externalipfinder.exe > MYip.txt
blat.exe MYip.txt -to %emailto% -u %emailfrom% -pw %password%
-f %emailfrom% -server -s "External IP"


And that’s it… have fun for any more questions email me at


One thought on “Internal to External IP’s (From Anywhere)

  1. […] and voila it will install without much user interaction. Now all you need is their IP (Refer to External IP Post), tell them to run the External IP Finder and give you their address, Log on and tell them to watch […]

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