*   <dt>An IPv6 "IPv4 mapped" address, {@code "::ffff:192.168.0.1"}.
 *   <dd>{@code 00 00 00 00 00 00 00 00 00 00 ff ff c0 a8 00 01}
 * </dl>
 *
 * <p>A few notes about IPv6 "IPv4 mapped" addresses and their observed use in Java.
 *
 * <p>"IPv4 mapped" addresses were originally a representation of IPv4 addresses for use on an IPv6
 * socket that could receive both IPv4 and IPv6 connections (by disabling the {@code IPV6_V6ONLY}

# window size, and how much to save for an application buffer.
net.ipv4.tcp_adv_win_scale=1

# disable RFC2861 behavior
net.ipv4.tcp_slow_start_after_idle = 0

# Fix faulty network setups
net.ipv4.tcp_mtu_probing=1
net.ipv4.tcp_base_mss=1280

# Disable ipv6
net.ipv6.conf.all.disable_ipv6=1
net.ipv6.conf.default.disable_ipv6=1
net.ipv6.conf.lo.disable_ipv6=1

[bootloader]

 *   <dt>An IPv6 "IPv4 mapped" address, {@code "::ffff:192.168.0.1"}.
 *   <dd>{@code 00 00 00 00 00 00 00 00 00 00 ff ff c0 a8 00 01}
 * </dl>
 *
 * <p>A few notes about IPv6 "IPv4 mapped" addresses and their observed use in Java.
 *
 * <p>"IPv4 mapped" addresses were originally a representation of IPv4 addresses for use on an IPv6
 * socket that could receive both IPv4 and IPv6 connections (by disabling the {@code IPV6_V6ONLY}

    InetAddress ipv4 = InetAddresses.forString("1.2.3.4");
    assertEquals(ipv4, InetAddresses.getEmbeddedIPv4ClientAddress(testIp));

    // Test 6to4 address.
    testIp = (Inet6Address) InetAddresses.forString("2002:0102:0304::1");
    assertTrue(InetAddresses.hasEmbeddedIPv4ClientAddress(testIp));
    ipv4 = InetAddresses.forString("1.2.3.4");
    assertEquals(ipv4, InetAddresses.getEmbeddedIPv4ClientAddress(testIp));

				// Number of probes.
				// ~ cat /proc/sys/net/ipv4/tcp_keepalive_probes (defaults to 9, we reduce it to 5)
				_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, syscall.TCP_KEEPCNT, 5)

				// Wait time after successful probe in seconds.
				// ~ cat /proc/sys/net/ipv4/tcp_keepalive_intvl (defaults to 75 secs, we reduce it to 15 secs)

# 1. IMAGE = docker image used as node by KinD
# 2. IP_FAMILY = either ipv4 or ipv6
#
# NOTE: Please call load_cluster_topology before calling this method as it expects
# cluster topology information to be loaded in advance
function setup_kind_clusters() {
  IMAGE="${1:-"${DEFAULT_KIND_IMAGE}"}"
  KUBECONFIG_DIR="${ARTIFACTS:-$(mktemp -d)}/kubeconfig"
  IP_FAMILY="${2:-ipv4}"

  check_default_cluster_yaml

	compareToGolden(t, false, tt.name, ext.ExecutedAll)
}

func ipstr(ipv6 bool) string {
	if ipv6 {
		return "ipv6"
	}
	return "ipv4"
}

func compareToGolden(t *testing.T, ipv6 bool, name string, actual []string) {
	t.Helper()
	gotBytes := []byte(strings.Join(actual, "\n"))
	goldenFile := filepath.Join("testdata", name+".golden")
	if ipv6 {
		goldenFile = filepath.Join("testdata", name+"_ipv6.golden")
	}

		// 127.0.0.1 is moved to the end of the list.
		if ipV4s[i].IsLoopback() {
			return false
		}
		if ipV4s[j].IsLoopback() {
			return true
		}
		return []byte(ipV4s[i].To4())[3] > []byte(ipV4s[j].To4())[3]
	})

	var ips []string
	for _, ip := range ipV4s {
		ips = append(ips, ip.String())
	}

	return append(nonIPs, ips...)
}

   * Generate an error if the host might be a non-bracketed IPv6 literal.
   *
   * <p>URI formatting requires that IPv6 literals be surrounded by brackets, like "[2001:db8::1]".
   * Chain this call after {@link #fromString(String)} to increase the strictness of the parser, and
   * disallow IPv6 literals that don't contain these brackets.
   *
   * <p>Note that this parser identifies IPv6 literals solely based on the presence of a colon. To

  # Docker on Windows doesn't support the `host` networking mode, and so
  # port-forwarding is required for the container to detect it's running on GCE.
  export IP_ADDR=$(powershell -command "(Get-NetIPAddress -AddressFamily IPv4 -InterfaceAlias 'vEthernet (nat)').IPAddress")
  netsh interface portproxy add v4tov4 listenaddress=$IP_ADDR listenport=80 connectaddress=169.254.169.254 connectport=80
  # A local firewall rule for the container is added in