$re = '/^(?:(?:10\.\d{1,3}\.\d{1,3}\.\d{1,3}|172\.(?:(?:1[6-9])|(?:2[0-9])|(?:3[0-1]))\.\d{1,3}\.\d{1,3}|192\.168\.\d{1,3}\.\d{1,3}|127\.\d{1,3}\.\d{1,3}\.\d{1,3})(?::\d{1,5})?)$/m';
$str = '127.0.0.1
127.255.255.255
127.0.0.1:3000
10.0.0.1
10.0.0.2
10.0.1.1
10.0.1.2:443
172.16.0.1
172.16.0.2
172.16.1.1
172.16.1.2
192.168.0.1
192.168.0.2
192.168.1.1
192.168.1.2
10.10.10.1
10.10.10.2
172.31.255.1
172.31.255.2
192.168.100.1
192.168.100.2
10.255.255.1
10.255.255.2
8.8.8.8:80
1.1.1.1
1.0.0.1
198.41.0.4
64.233.160.0
208.67.222.222:8080';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php