{xRealIP, "[2001:db8:cafe::17]:4711", "[2001:db8:cafe::17]"},                  // IPv6 address
		{xRealIP, "", ""},                                                             // None
		{forwarded, `for="_gazonk"`, "_gazonk"},                                       // Hostname
		{forwarded, `For="[2001:db8:cafe::17]:4711`, `[2001:db8:cafe::17]`},           // IPv6 address

	"github.com/minio/minio-go/v7/pkg/set"
	"github.com/minio/minio/internal/config"
	"github.com/minio/minio/internal/logger"
	xnet "github.com/minio/pkg/v3/net"
)

var (
	// IPv4 addresses of localhost.
	localIP4 = mustGetLocalIP4()

	// IPv6 addresses of localhost.
	localIP6 = mustGetLocalIP6()

	// List of all local loopback addresses.
	localLoopbacks = mustGetLocalLoopbacks()
)

 * Prefer to alternate IP addresses from different address families, (IPv6 / IPv4), starting with IPv6.
 * Don't start a new attempt until 250 ms after the most recent attempt was started.
 * Keep whichever TCP connection succeeds first and cancel all the others.

	printCLIAccessMsg(strippedAPIEndpoints[0], "myminio")

	// Prints documentation message.
	printObjectAPIMsg()
	if globalIsDistErasure {
		logger.Startup(color.Bold(banner))
	}
}

// Returns true if input is IPv6
func isIPv6(host string) bool {
	h, _, err := net.SplitHostPort(host)
	if err != nil {
		h = host
	}
	ip := net.ParseIP(h)
	return ip.To16() != nil && ip.To4() == nil
}

        @ParameterizedTest
        @DisplayName("Should handle IPv6 addresses correctly")
        @CsvSource({ "'ncacn_np:[::1][endpoint=\\pipe\\srvsvc]', ncacn_np, '[::1]', '\\pipe\\srvsvc'" })
        void testParseIPv6BindingUrls(String url, String expectedProto, String expectedServer, String expectedEndpoint)
                throws DcerpcException {
            // When: Parsing IPv6 binding URL

        // SockaddrStorage (128 bytes)
        encodeSockaddr(buffer, 20);
        
        return buffer;
    }
    
    private void encodeSockaddr(byte[] buffer, int offset) {
        if (ipv6) {
            // IPv6 sockaddr_in6 structure
            writeInt2(buffer, offset, 23);  // AF_INET6
            writeInt2(buffer, offset + 2, 445);  // Port
            writeInt4(buffer, offset + 4, 0);  // Flow info

 * [system DNS service][SYSTEM], which is the default. Some applications may provide their own
 * implementation to use a different DNS server, to prefer IPv6 addresses, to prefer IPv4 addresses,
 * or to force a specific known IP address.
 *
 * Implementations of this interface must be safe for concurrent use.
 */
fun interface Dns {
  /**

      val inetAddress = socket.localAddress

      var hostname = inetAddress.hostName
      if (inetAddress is Inet6Address && hostname.contains(':')) {
        // hostname is likely some form representing the IPv6 bytes
        // 2001:0db8:85a3:0000:0000:8a2e:0370:7334
        // 2001:db8:85a3::8a2e:370:7334
        // ::1
        hostname = "[$hostname]"
      }

      val localPort = socket.localPort

_2022-02-01_

**This release introduces fast fallback to better support mixed IPv4+IPv6 networks.** Fast fallback
is what we're calling our implementation of Happy Eyeballs, [RFC 8305][rfc_8305]. With this
feature OkHttp will attempt both IPv6 and IPv4 connections concurrently, keeping whichever connects
first. Fast fallback gives IPv6 connections a 250 ms head start so IPv6 is preferred on networks
where it's available.

  private fun decodeIpv6(input: String): ByteArray? = decodeIpv6(input, 0, input.length)

  @Test
  fun testToCanonicalHost() {
    // IPv4
    assertThat("127.0.0.1".toCanonicalHost()).isEqualTo("127.0.0.1")
    assertThat("1.2.3.4".toCanonicalHost()).isEqualTo("1.2.3.4")

    // IPv6
    assertThat("::1".toCanonicalHost()).isEqualTo("::1")
    assertThat("2001:db8::1".toCanonicalHost()).isEqualTo("2001:db8::1")