Scala - Pattern match extractors, Regex domain names, IPv4, IPv6

RegexExtractorDomainName.scala

    /** Parse any IPv4 address or IPv6 address or domain name */
    def parsePeerAddress(value: String): Try[String] =
      parseIPv4(value) orElse parseIPv6(value) orElse parseHostname(value)

    /** Parse IPv4 address */
    def parseIPv4(value: String): Try[String] =
      value.trim match {
        case regexIPv4(_*) => Success(value)
        case _             => Failure(new IllegalArgumentException(s"invalid IPv4 address name: ${value.trim}"))
      }

    /** Parse IPv6 address */
    def parseIPv6(value: String): Try[String] =
      value.trim.toUpperCase match {
        case regexIPv6(_*) => Success(value)
        case _             => Failure(new IllegalArgumentException(s"invalid IPv4 address name: ${value.trim}"))
      }

    /** Performs a DNS query, trying to resolve hostname. */
    def parseHostname(hostname: String): Try[String] = {
      def checkEmpty(hostname: String): Try[String] =
        if(hostname.length == 0) Failure(new java.net.UnknownHostException()) else Success(hostname)
      def resolve(hostname: String): Try[String] =
        Try { java.net.InetAddress.getByName(hostname).toString }
      def checkInvalid(address: String): Try[String] =
        if(address.startsWith("/"))  Failure(new java.net.UnknownHostException(address)) else Success(address)

      checkEmpty(hostname.trim)
        .flatMap(resolve)
        .flatMap(checkInvalid)
    }

    //credits: Regular Expressions Cookbook by Steven Levithan, Jan Goyvaerts
    /** Regular expression which matches a IPv4 address */
    val regexIPv4 = "^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$".r


    //credits: Regular Expressions Cookbook by Steven Levithan, Jan Goyvaerts
    /** Regular expression which matches a IPv6 address */
    val regexIPv6 = "^(?:(?:(?:[A-F0-9]{1,4}:){6}|(?=(?:[A-F0-9]{0,4}:){0,6}(?:[0-9]{1,3}\\.){3}[0-9]{1,3}$)(([0-9A-F]{1,4}:){0,5}|:)((:[0-9A-F]{1,4}){1,5}:|:))(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)|(?:[A-F0-9]{1,4}:){7}[A-F0-9]{1,4}|(?=(?:[A-F0-9]{0,4}:){0,7}[A-F0-9]{0,4}$)(([0-9A-F]{1,4}:){1,7}|:)((:[0-9A-F]{1,4}){1,7}|:))$".r