Regular expression for IP address
Regular expression for IP address: Regex for IPv4 /^((2[0-4]|1\d|[1-9])?\d|25[0-5])(\.(?1)){3}\z/ Regex for IPv6 /^(((?=(?>.*?(::))(?!.+\3)))\3?|([\dA-F]{1,4}(\3|:(?!$)|$)|\2))(?4){5}((?4){2}|((2[0-4]|1\d|[1-9])?\d|25[0-5])(\.(?7)){3})\z/i