+my $IPV4OCTET = "(?:25[0-5]|(?:[1-9]|1[0-9]|2[0-4])?[0-9])";
+our $IPV4RE = "(?:(?:$IPV4OCTET\\.){3}$IPV4OCTET)";
+my $IPV6H16 = "(?:[0-9a-fA-F]{1,4})";
+my $IPV6LS32 = "(?:(?:$IPV4RE|$IPV6H16:$IPV6H16))";
+
+our $IPV6RE = "(?:" .
+ "(?:(?:" . "(?:$IPV6H16:){6})$IPV6LS32)|" .
+ "(?:(?:" . "::(?:$IPV6H16:){5})$IPV6LS32)|" .
+ "(?:(?:(?:" . "$IPV6H16)?::(?:$IPV6H16:){4})$IPV6LS32)|" .
+ "(?:(?:(?:(?:$IPV6H16:){0,1}$IPV6H16)?::(?:$IPV6H16:){3})$IPV6LS32)|" .
+ "(?:(?:(?:(?:$IPV6H16:){0,2}$IPV6H16)?::(?:$IPV6H16:){2})$IPV6LS32)|" .
+ "(?:(?:(?:(?:$IPV6H16:){0,3}$IPV6H16)?::(?:$IPV6H16:){1})$IPV6LS32)|" .
+ "(?:(?:(?:(?:$IPV6H16:){0,4}$IPV6H16)?::" . ")$IPV6LS32)|" .
+ "(?:(?:(?:(?:$IPV6H16:){0,5}$IPV6H16)?::" . ")$IPV6H16)|" .
+ "(?:(?:(?:(?:$IPV6H16:){0,6}$IPV6H16)?::" . ")))";
+