ip check prior to post

To only admit a single ip that can post to tables, what is the correct way when given an address containing the */ to check against?

$ip = $_SERVER['REMOTE_ADDR'];
if ($ip=='444.33.77.*/55')
{

$_SERVER['REMOTE_ADDR'] is far from reliable, what exaclty are you trying to do?

verifying the ip address on a postback form is in fact gateway ip, before the connection and insert.

//thought this was enough in itself for a seperate post, since linked post included (2) main questions in itself.