PHP Language

I need help. When I get the user's IP address I need to verify if they are or not under a certain domain. Below is the original question and my code.

Original Question: Display a message You are (NOT) from Kean domain. under the IP address, if the customer (NOT) login from Kean domain (10.*.*.*) or (131.125.*.*)

ie

Here is the code I have so far it just receives a persons IP

$ip = $_SERVER['REMOTE_ADDR'];

echo " Your IP Address is: $ip ";

$IPv4= explode(",",$ip);

Your IP: 100.100.100.100 You are NOT from Kean Unversity. Your IP: 100.100.100.100 You are NOT from Kean Unversity