I’m running a Thin-Client as a home server and sometimes I need access to some files at home. Since those no-ip services didn’t prove that reliable in the past, I decided to implement a DynDNS substitute in PHP.

The concept is quite simple: Let the little server at home call a PHP script somewhere on a “big” Server that has a static IP. The big server then writes the IP to a file, so it can be read from anywhere. There are two scripts that have to reside on the big server: an index.php, which reads and echoes the IP, that was recorded, and another script in a .htaccess protected folder, which is able to write the IP of the home server to a file.


echo file_get_contents("ip");


$fh = fopen("../ip", 'w') or die("can't open file");
fwrite($fh, $_SERVER['REMOTE_ADDR']);

By putting the setip.php inside a .htaccess protected folder you’re making sure that the IP is only set by your home server and nobody else.

The only thing that’s left to do, is to set a cron job on your home server, that calls this script once in a while. So call the crontab editor as root

crontab -e

and add a line to call wget every 5 minutes, for example. (the user and pass should of course be the ones defined in your .htpasswd.

*/5 * * * * * wget -O - --http-user=user --http-password=pass domain.com/p/setip.php

There you have it, you own cheap DynDNS service in just 3 minutes. To use it, just open domain.com/index.php in your browser, or even better, add a bash alias like this:

alias homeserver='`wget -q -O - domain.com/index.php`'

Now you can use homeserver inside your terminal as if it would be in your /etc/hosts.