@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")
    assertThat("::ffff:192.168.0.1".toCanonicalHost()).isEqualTo("192.168.0.1")
    assertThat(

			// addresses (for=8.8.8.8, 8.8.4.4, 172.16.1.20 is valid) we only
			// extract the first, which should be the client IP.
			if match := forRegex.FindStringSubmatch(fwd); len(match) > 1 {
				// IPv6 addresses in Forwarded headers are quoted-strings. We strip
				// these quotes.
				addr = strings.Trim(match[1], `"`)
			}
		}
	}

	return addr
}

		*outReq = *quietReq
	}
}

// headerRewriter is responsible for removing hop-by-hop headers and setting forwarding headers
type headerRewriter struct{}

// Clean up IP in case if it is ipv6 address and it has {zone} information in it, like
// "[fe80::d806:a55d:eb1b:49cc%vEthernet (vmxnet3 Ethernet Adapter - Virtual Switch)]:64692"
func ipv6fix(clientIP string) string {
	return strings.Split(clientIP, "%")[0]
}

          }

          call.eventListener.dnsEnd(call, socketHost, result)
          result
        }

      // Try each address for best behavior in mixed IPv4/IPv6 environments.
      val orderedAddresses =
        when {
          fastFallback -> reorderForHappyEyeballs(addresses)
          else -> addresses
        }

      for (inetAddress in orderedAddresses) {

 *  Fix: Don't use a cryptographic random number generator for web sockets. Some Android devices
    implement `SecureRandom` incorrectly!
 *  Fix: Correctly canonicalize IPv6 addresses in `HttpUrl`. This prevented OkHttp from trusting
    HTTPS certificates issued to certain IPv6 addresses.
 *  Fix: Don't reuse connections after an unsuccessful `Expect: 100-continue`.

        private final int flags;
        
        public static final int IPV4 = 0x01;
        public static final int IPV6 = 0x02;
        
        public WitnessIPAddress(InetAddress address) {
            this.address = address;
            this.flags = address.getAddress().length == 4 ? IPV4 : IPV6;
        }
        
        public InetAddress getAddress() { return address; }

`--node-cidr-mask-size-ipv6 int32`     Default: 64. Mask size for IPv6 node-cidr in dual-stack cluster.

    These 2 flags can be used only for dual-stack clusters. For non dual-stack clusters, continue to use  `--node-cidr-mask-size` flag to configure the mask size.

    InetAddress ip = InetAddresses.forString(ipStr);
    assertThat(InetAddresses.toUriString(ip)).isEqualTo("1.2.3.4");
  }

  public void testToUriStringIPv6() {
    // Unfortunately the InetAddress.toString() method for IPv6 addresses
    // does not collapse contiguous shorts of zeroes with the :: abbreviation.
    String ipStr = "3ffe::1";
    InetAddress ip = InetAddresses.forString(ipStr);

problems. If your service has multiple IP addresses, OkHttp will attempt alternate addresses if the
first connect fails. This is necessary for IPv4+IPv6 and services hosted in redundant data
centers. OkHttp supports modern TLS features (TLS 1.3, ALPN, certificate pinning). It can be
configured to fall back for broad connectivity.

### **Network**

#### **IPv6**

*   [alpha] IPv6 support has been added. Notable IPv6 support details include:
    *   Support for IPv6-only Kubernetes cluster deployments. **<span style="text-decoration:underline;">Note:</span>** This feature does not provide dual-stack support.
    *   Support for IPv6 Kubernetes control and data planes.
    *   Support for Kubernetes IPv6 cluster deployments using kubeadm.