This is offtopic, but as I tried to explain earlier it's not your server's configuration. include() function uses to execute PHP code from a different file. When you access any .php files via remote address (http://) it executes that .php file on that remote server, so when your server tries include that .php file it gets the generated by that file output, which is usually HTML code, not PHP source code of that file.
Now, if you'd rename random2.php to random2.txt, then it might work, because remote server would simply output text inside that file, not execute it.