$IP
=
"198.168.1.1"
;
if
(preg_match(
'/^(([1-9]?[0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]).){3}([1-9]?[0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$/'
,
)) {
echo
"Your IP address is ok."
}
else
{
"Wrong IP address."