extraConfig        string
	}{
		{
			name:               "iptables mode, IPv4 all-zeros bind address",
			mode:               "iptables",
			bindAddress:        "0.0.0.0",
			clusterCIDR:        "1.2.3.0/24",
			healthzBindAddress: "1.2.3.4:12345",
			metricsBindAddress: "2.3.4.5:23456",
		},
		{
			name:               "iptables mode, non-zeros IPv4 config",
			mode:               "iptables",
			bindAddress:        "9.8.7.6",

	// Should return 200 "OK" after processing update for both IPv4 and IPv6 proxiers.
	hs.Updated(v1.IPv4Protocol)
	hs.Updated(v1.IPv6Protocol)
	fakeClock.Step(5 * time.Second)
	testHTTPHandler(hsTest, http.StatusOK, t)

	// If IPv6 proxier is late for an update but IPv4 proxier is not then updating IPv4 proxier should have no effect.
	hs.QueuedUpdate(v1.IPv6Protocol)
	fakeClock.Step(25 * time.Second)

				},
				ClusterConfiguration: kubeadmapi.ClusterConfiguration{
					ControlPlaneEndpoint: "cp.k8s.io:1234",
				},
			},
			expectedEndpoint: "https://cp.k8s.io:1234",
		},
		{
			name: "use ControlPlaneEndpoint (ipv4) if fully defined",
			cfg: &kubeadmapi.InitConfiguration{
				LocalAPIEndpoint: kubeadmapi.APIEndpoint{
					BindPort:         4567,
					AdvertiseAddress: "4.5.6.7",
				},

			serviceCidr: "10.96.0.0/16,fda9:d324:354d:1::/112",
			expStr:      []string{"FileContent--proc-sys-net-ipv4-ip_forward", "FileContent--proc-sys-net-ipv6-conf-default-forwarding"},
		},
		{
			testName:    "single stack ipv4",
			PodSubnet:   "10.244.0.0/16",
			serviceCidr: "10.96.0.0/16",
			expStr:      []string{"FileContent--proc-sys-net-ipv4-ip_forward"},
		},
		{
			testName:    "single stack ipv6",

		ln.Close()
	}
}

var ipv4MulticastListenerTests = []struct {
	net   string
	gaddr *UDPAddr // see RFC 4727
}{
	{"udp", &UDPAddr{IP: IPv4(224, 0, 0, 254), Port: 12345}},

	{"udp4", &UDPAddr{IP: IPv4(224, 0, 0, 254), Port: 12345}},
}

// TestIPv4MulticastListener tests both single and double listen to a
// test listener with same address family, same group address and same
// port.

	nt = proto.Clone(nt).(*dnsProto.NameTable)
	d.BuildAlternateHosts(nt, func(althosts map[string]struct{}, ipv4 []netip.Addr, ipv6 []netip.Addr, _ []string) {
		for host := range althosts {
			if _, exists := nt.Table[host]; !exists {
				addresses := make([]string, 0, len(ipv4)+len(ipv6))
				for _, addr := range ipv4 {
					addresses = append(addresses, addr.String())
				}
				for _, addr := range ipv6 {

	// serve on, defaulting to "0.0.0.0:10256" (if bindAddress is unset or IPv4), or
	// "[::]:10256" (if bindAddress is IPv6).
	HealthzBindAddress string
	// metricsBindAddress is the IP address and port for the metrics server to serve
	// on, defaulting to "127.0.0.1:10249" (if bindAddress is unset or IPv4), or
	// "[::1]:10249" (if bindAddress is IPv6). (Set to "0.0.0.0:10249" / "[::]:10249"

						Ingress: []v1.LoadBalancerIngress{
							{IP: testExternalIPv4},
							{IP: testExternalIPv6},
						},
					},
				},
			},
		},
		{
			desc:     "service with ipv4 configurations under ipv4 mode",
			ipFamily: v1.IPv4Protocol,

			service: &v1.Service{
				ObjectMeta: metav1.ObjectMeta{
					Name:      "validIPv4",
					Namespace: "test",
				},
				Spec: v1.ServiceSpec{

		// Returns a slow IPv6 address, and a local IPv4 address.
		return []IPAddr{
			{IP: ParseIP(slowDst6)},
			{IP: ParseIP("127.0.0.1")},
		}, nil
	default:
		return fn(ctx, network, host)
	}
}

func TestDialerFallbackDelay(t *testing.T) {
	testenv.MustHaveExternalNetwork(t)

	if !supportsIPv4() || !supportsIPv6() {
		t.Skip("both IPv4 and IPv6 are required")
	}

	dualstack, _ := netutils.IsDualStackCIDRs(cidrs)

	return cidrs, dualstack, nil
}

// setNodeCIDRMaskSizes returns the IPv4 and IPv6 node cidr mask sizes to the value provided
// for --node-cidr-mask-size-ipv4 and --node-cidr-mask-size-ipv6 respectively. If value not provided,
// then it will return default IPv4 and IPv6 cidr mask sizes.