$re = '/\b(?:(?:i|sir|ami|snap|vol|ssi|Ipv4)\b(?:-[a-zA-Z0-9]+)?|(?:[0-9]{1,3}\.){3}[0-9]{1,3}(?:\s*,\s*(?:[0-9]{1,3}\.){3}[0-9]{1,3})*)\b/m';
$str = 'i-XXXX, sir-XXXX, ami-XXXX, vol-XXXX, snap-XXXX, 123.123.123.123';
preg_match_all($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