@@ -89,8 +89,7 @@ var errSwarmCertificatesExpired = errors.New("Swarm certificates have expired. T

 // NetworkSubnetsProvider exposes functions for retrieving the subnets

 // of networks managed by Docker, so they can be filtered.

 type NetworkSubnetsProvider interface {

-	V4Subnets() []net.IPNet

-	V6Subnets() []net.IPNet

+	Subnets() ([]net.IPNet, []net.IPNet)

 }

 // Config provides values for Cluster.

@@ -162,8 +162,7 @@ func (c *Cluster) resolveSystemAddrViaSubnetCheck() (net.IP, error) {

 	var systemInterface string

 	// List Docker-managed subnets

-	v4Subnets := c.config.NetworkSubnetsProvider.V4Subnets()

-	v6Subnets := c.config.NetworkSubnetsProvider.V6Subnets()

+	v4Subnets, v6Subnets := c.config.NetworkSubnetsProvider.Subnets()

 ifaceLoop:

 	for _, intf := range interfaces {

@@ -878,40 +878,28 @@ func (daemon *Daemon) Unmount(container *container.Container) error {

 	return nil

 }

-// V4Subnets returns the IPv4 subnets of networks that are managed by Docker.

-func (daemon *Daemon) V4Subnets() []net.IPNet {

-	var subnets []net.IPNet

+// Subnets return the IPv4 and IPv6 subnets of networks that are manager by Docker.

+func (daemon *Daemon) Subnets() ([]net.IPNet, []net.IPNet) {

+	var v4Subnets []net.IPNet

+	var v6Subnets []net.IPNet

 	managedNetworks := daemon.netController.Networks()

 	for _, managedNetwork := range managedNetworks {

-		v4Infos, _ := managedNetwork.Info().IpamInfo()

-		for _, v4Info := range v4Infos {

-			if v4Info.IPAMData.Pool != nil {

-				subnets = append(subnets, *v4Info.IPAMData.Pool)

+		v4infos, v6infos := managedNetwork.Info().IpamInfo()

+		for _, info := range v4infos {

+			if info.IPAMData.Pool != nil {

+				v4Subnets = append(v4Subnets, *info.IPAMData.Pool)

 			}

 		}

-	}

-

-	return subnets

-}

-

-// V6Subnets returns the IPv6 subnets of networks that are managed by Docker.

-func (daemon *Daemon) V6Subnets() []net.IPNet {

-	var subnets []net.IPNet

-

-	managedNetworks := daemon.netController.Networks()

-

-	for _, managedNetwork := range managedNetworks {

-		_, v6Infos := managedNetwork.Info().IpamInfo()

-		for _, v6Info := range v6Infos {

-			if v6Info.IPAMData.Pool != nil {

-				subnets = append(subnets, *v6Info.IPAMData.Pool)

+		for _, info := range v6infos {

+			if info.IPAMData.Pool != nil {

+				v6Subnets = append(v6Subnets, *info.IPAMData.Pool)

 			}

 		}

 	}

-	return subnets

+	return v4Subnets, v6Subnets

 }

 // GraphDriverName returns the name of the graph driver used by the layer.Store