if len(mockIntercept.lastRedirect) == 0 {
		t.Fatalf("expected nsenterFunc to be called")
	}
	r := mockIntercept.lastRedirect[len(mockIntercept.lastRedirect)-1]
	if !r.dualStack {
		t.Fatalf("expect dualStack is true, actual %v", r.dualStack)
	}
}

func Test_dedupPorts(t *testing.T) {
	type args struct {
		ports []string
	}
	tests := []struct {
		name string
		args args
		want []string

}

var dialGoogleTests = []struct {
	dial               func(string, string) (Conn, error)
	unreachableNetwork string
	networks           []string
	addrs              []string
}{
	{
		dial:     (&Dialer{DualStack: true}).Dial,
		networks: []string{"tcp", "tcp4", "tcp6"},
		addrs:    []string{"www.google.com:http"},
	},
	{
		dial:               Dial,
		unreachableNetwork: "tcp6",
		networks:           []string{"tcp", "tcp4"},

	IPFamilies string

	// IPFamilyPolicy. This is optional field. Mainly is used for dual stack testing.
	IPFamilyPolicy string

	DualStack bool

	// ServiceWaypointProxy specifies if this workload should have an associated Waypoint for service-addressed traffic
	ServiceWaypointProxy string

	IptablesProbePort         = "iptables-probe-port"
	ProbeTimeout              = "probe-timeout"
	RedirectDNS               = "redirect-dns"
	DropInvalid               = "drop-invalid"
	DualStack                 = "dual-stack"
	CaptureAllDNS             = "capture-all-dns"
	NetworkNamespace          = "network-namespace"
	CNIMode                   = "cni-mode"
)

	return hcnObj.supportedFeatures
}

func (hcnObj HcnMock) Ipv6DualStackSupported() error {
	if hcnObj.supportedFeatures.IPv6DualStack {
		return nil
	}
	return errors.New("IPV6 DualStack Not Supported")
}

func (hcnObj HcnMock) DsrSupported() error {
	if hcnObj.supportedFeatures.DSR {
		return nil
	}
	return errors.New("DSR Not Supported")
}

	LocalAddr Addr

	// DualStack previously enabled RFC 6555 Fast Fallback
	// support, also known as "Happy Eyeballs", in which IPv4 is
	// tried soon if IPv6 appears to be misconfigured and
	// hanging.
	//
	// Deprecated: Fast Fallback is enabled by default. To
	// disable, set FallbackDelay to a negative value.
	DualStack bool

	// FallbackDelay specifies the length of time to wait before

			lns = append(lns, ln)
		}
		if len(lns) != len(args) {
			for _, ln := range lns {
				ln.Close()
			}
			continue
		}
		return lns, nil
	}
	return nil, errors.New("no dualstack port available")
}

type localServer struct {
	lnmu sync.RWMutex
	Listener
	done chan bool // signal that indicates server stopped
	cl   []Conn    // accepted connection list
}

			IPFamilyPolicy:  "RequireDualStack",
			DualStack:       true,
		}
		eSvc := echo.Config{
			Service:         ESvc,
			ServiceAccount:  true,
			Ports:           ports.All(),
			Subsets:         []echo.SubsetConfig{{}},
			IncludeExtAuthz: c.IncludeExtAuthz,
			IPFamilies:      "IPv6",
			IPFamilyPolicy:  "SingleStack",
			DualStack:       true,
		}

func Wildcard(value WildcardValue) Instance {
	return newOption("wildcard", value)
}

func AdditionalWildCard(value WildcardValue) Instance {
	return newOption("additional_wildcard", value)
}

func DualStack(value bool) Instance {
	return newOption("dual_stack", value)
}

func DNSLookupFamily(value DNSLookupFamilyValue) Instance {
	return newOption("dns_lookup_family", value)
}

		discovery      cluster.Cluster_DiscoveryType
		proxy          *model.Proxy
		dualStack      bool
		expectedFamily cluster.Cluster_DnsLookupFamily
	}{
		{
			name:           "all ipv4, dual stack disabled",
			clusterName:    "foo",
			discovery:      cluster.Cluster_STRICT_DNS,
			proxy:          getProxy(),
			dualStack:      false,
			expectedFamily: cluster.Cluster_V4_ONLY,
		},
		{