_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.

			// 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`.

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.

`--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.

		"",
	)

	ErrInvalidAddressFlag = newErrFn(
		"--address input is invalid",
		"Please check --address parameter",
		`--address binds to a specific ADDRESS:PORT, ADDRESS can be an IPv4/IPv6 address or hostname (default port is ':9000')
	Examples: --address ':443'
		  --address '172.16.34.31:9000'
		  --address '[fe80::da00:a6c8:e3ae:ddd7]:9000'`,
	)

	ErrInvalidEndpoint = newErrFn(

 * authentication.
 *
 * ### Host
 *
 * The host identifies the webserver that serves the URL's resource. It is either a hostname like
 * `square.com` or `localhost`, an IPv4 address like `192.168.0.1`, or an IPv6 address like `::1`.
 *
 * Usually a webserver is reachable with multiple identifiers: its IP addresses, registered
 * domain names, and even `localhost` when connecting from the server itself. Each of a web server's

- Fixed the EndpointSliceController to correctly create endpoints for IPv6-only pods.
  
  Fixed the EndpointController to allow IPv6 headless services, if the IPv6DualStack
  feature gate is enabled, by specifying `ipFamily: IPv6` on the service. (This already