@@ -1188,10 +1188,18 @@ func (container *Container) allocateNetwork() error {

 			portJob.Setenv("Proto", port.Proto())

 			portJob.Setenv("ContainerPort", port.Port())

+			portEnv, err := portJob.Stdout.AddEnv()

+			if err != nil {

+				return err

+			}

 			if err := portJob.Run(); err != nil {

 				eng.Job("release_interface", container.ID).Run()

 				return err

 			}

+			b.HostIp = portEnv.Get("HostIP")

+			b.HostPort = portEnv.Get("HostPort")

+

+			binding[i] = b

 		}

 		bindings[port] = binding

 	}

@@ -50,10 +50,10 @@ var (

 		"192.168.44.1/24",

 	}

-	bridgeIface      string

-	defaultBindingIP net.IP

-	bridgeNetwork    *net.IPNet

+	bridgeIface   string

+	bridgeNetwork *net.IPNet

+	defaultBindingIP  = net.ParseIP("0.0.0.0")

 	currentInterfaces = make(map[string]*networkInterface)

 )

@@ -72,7 +72,9 @@ func InitDriver(job *engine.Job) engine.Status {

 		bridgeIP       = job.Getenv("BridgeIP")

 	)

-	defaultBindingIP = net.ParseIP(job.Getenv("DefaultBindingIP"))

+	if defaultIP := job.Getenv("DefaultBindingIP"); defaultIP != "" {

+		defaultBindingIP = net.ParseIP(defaultIP)

+	}

 	bridgeIface = job.Getenv("BridgeIface")

 	if bridgeIface == "" {

@@ -382,6 +384,8 @@ func Release(job *engine.Job) engine.Status {

 // Allocate an external port and map it to the interface

 func AllocatePort(job *engine.Job) engine.Status {

 	var (

+		err error

+

 		ip            = defaultBindingIP

 		id            = job.Args[0]

 		hostIP        = job.Getenv("HostIP")

@@ -396,7 +400,7 @@ func AllocatePort(job *engine.Job) engine.Status {

 	}

 	// host ip, proto, and host port

-	hostPort, err := portallocator.RequestPort(ip, proto, hostPort)

+	hostPort, err = portallocator.RequestPort(ip, proto, hostPort)

 	if err != nil {

 		job.Error(err)

 		return engine.StatusErr

@@ -423,6 +427,14 @@ func AllocatePort(job *engine.Job) engine.Status {

 	}

 	network.PortMappings = append(network.PortMappings, host)

+	out := engine.Env{}

+	out.Set("HostIP", ip.String())

+	out.SetInt("HostPort", hostPort)

+

+	if _, err := out.WriteTo(job.Stdout); err != nil {

+		job.Error(err)

+		return engine.StatusErr

+	}

 	return engine.StatusOK

 }

@@ -51,7 +51,7 @@ func RequestPort(ip net.IP, proto string, port int) (int, error) {

 	}

 	// If the user requested a specific port to be allocated

-	if port != 0 {

+	if port > 0 {

 		if err := registerSetPort(ip, proto, port); err != nil {

 			return 0, err

 		}