HardwareAddr HardwareAddr // IEEE MAC-48, EUI-48 and EUI-64 form
	Flags        Flags        // e.g., FlagUp, FlagLoopback, FlagMulticast
}

type Flags uint

const (
	FlagUp           Flags = 1 << iota // interface is administratively up
	FlagBroadcast                      // interface supports broadcast access capability
	FlagLoopback                       // interface is a loopback interface

					ifc.HardwareAddr = ifc.HardwareAddr[:i]
					break
				}
			}
		}

		ifc.Flags = FlagUp | FlagRunning | FlagBroadcast | FlagMulticast
	} else {
		ifc.Flags = FlagUp | FlagRunning | FlagMulticast | FlagLoopback
	}

	return ifc, nil
}

func interfaceCount() (int, error) {
	d, err := os.Open(netdir + "/ipifc")
	if err != nil {
		return -1, err
	}
	defer d.Close()

// found.
func loopbackInterface() *Interface {
	ift, err := Interfaces()
	if err != nil {
		return nil
	}
	for _, ifi := range ift {
		if ifi.Flags&FlagLoopback != 0 && ifi.Flags&FlagUp != 0 {
			return &ifi
		}
	}
	return nil
}

// ipv6LinkLocalUnicastAddr returns an IPv6 link-local unicast address
// on the given network interface for tests. It returns "" if no

				ifi.Flags |= FlagBroadcast | FlagMulticast
			case windows.IF_TYPE_PPP, windows.IF_TYPE_TUNNEL:
				ifi.Flags |= FlagPointToPoint | FlagMulticast
			case windows.IF_TYPE_SOFTWARE_LOOPBACK:
				ifi.Flags |= FlagLoopback | FlagMulticast
			case windows.IF_TYPE_ATM:
				ifi.Flags |= FlagBroadcast | FlagPointToPoint | FlagMulticast // assume all services available; LANE, point-to-point and point-to-multipoint
			}
			if aa.Mtu == 0xffffffff {

	ok := true
	ipAddresses := make([]string, 0)

	ifaces, _ := net.Interfaces()

	for _, iface := range ifaces {
		if iface.Flags&net.FlagUp == 0 {
			continue // interface down
		}
		if iface.Flags&net.FlagLoopback != 0 {
			continue // loopback interface
		}
		addrs, _ := iface.Addrs()

		for _, addr := range addrs {
			var ip net.IP
			switch v := addr.(type) {
			case *net.IPNet:
				ip = v.IP

// for loopback test.
func LoopbackInterface() (*net.Interface, error) {
	ift, err := net.Interfaces()
	if err != nil {
		return nil, errNoAvailableInterface
	}
	for _, ifi := range ift {
		if ifi.Flags&net.FlagLoopback != 0 && ifi.Flags&net.FlagUp != 0 {
			return &ifi, nil
		}
	}
	return nil, errNoAvailableInterface
}

// RoutedInterface returns a network interface that can route IP
// traffic and satisfies flags.

	checkGetmac(t)

	ift, err := Interfaces()
	if err != nil {
		t.Fatal(err)
	}
	have := make(map[string]string)
	for _, ifi := range ift {
		if ifi.Flags&FlagLoopback != 0 {
			// no MAC address for loopback interfaces
			continue
		}
		have[ifi.Name] = ifi.HardwareAddr.String()
	}

	out, err := runCmd("getmac", "/fo", "list", "/v")
	if err != nil {

		{"ErrWriteToConnected", Var, 0},
		{"Error", Type, 0},
		{"FileConn", Func, 0},
		{"FileListener", Func, 0},
		{"FilePacketConn", Func, 0},
		{"FlagBroadcast", Const, 0},
		{"FlagLoopback", Const, 0},
		{"FlagMulticast", Const, 0},
		{"FlagPointToPoint", Const, 0},
		{"FlagRunning", Const, 20},
		{"FlagUp", Const, 0},
		{"Flags", Type, 0},
		{"HardwareAddr", Type, 0},