Question

Ok I am looking into see if it is possible to get the DNS of a computer using PHP. I am aware that PHP allows for getting DNS info for a website or server but can it be done to cross reference a computers DNS somehow using $_SERVER[‘REMOTE_ADDR’] and other PHP functions.

Answer 1

You can use gethostbyaddr for this:

$hostname = gethostbyaddr($_SERVER['REMOTE_ADDR']);

However, I must warn you that $_SERVER['REMOTE_ADDR'] can have a few forms; here are a few articles that talk about this value:

• problem with $_SERVER['REMOTE_ADDR']
• REMOTE_ADDR and IPv6 in PHP