@@ -376,7 +376,9 @@ func (o CreateNodeConfigOptions) MakeNodeConfig(serverCertFile, serverKeyFile, n

 		MasterKubeConfig: kubeConfigFile,

-		NetworkPluginName: o.NetworkPluginName,

+		NetworkConfig: configapi.NodeNetworkConfig{

+			NetworkPluginName: o.NetworkPluginName,

+		},

 	}

 	if o.UseTLS() {

@@ -46,8 +46,8 @@ type NodeConfig struct {

 	// DNSIP holds the IP

 	DNSIP string

-	// NetworkPluginName is a string specifying the networking plugin

-	NetworkPluginName string

+	// NetworkConfig provides network options for the node

+	NetworkConfig NodeNetworkConfig

 	// VolumeDir is the directory that volumes will be stored under

 	VolumeDirectory string

@@ -71,6 +71,14 @@ type NodeConfig struct {

 	KubeletArguments ExtendedArguments

 }

+// NodeNetworkConfig provides network options for the node

+type NodeNetworkConfig struct {

+	// NetworkPluginName is a string specifying the networking plugin

+	NetworkPluginName string

+	// Maximum transmission unit for the network packets

+	MTU uint

+}

+

 // DockerConfig holds Docker related configuration options.

 type DockerConfig struct {

 	// ExecHandlerName is the name of the handler to use for executing

@@ -169,7 +177,7 @@ type MasterConfig struct {

 	RoutingConfig RoutingConfig

 	// NetworkConfig to be passed to the compiled in network plugin

-	NetworkConfig NetworkConfig

+	NetworkConfig MasterNetworkConfig

 }

 type ProjectConfig struct {

@@ -226,8 +234,8 @@ type PolicyConfig struct {

 	OpenShiftInfrastructureNamespace string

 }

-// NetworkConfig to be passed to the compiled in network plugin

-type NetworkConfig struct {

+// MasterNetworkConfig to be passed to the compiled in network plugin

+type MasterNetworkConfig struct {

 	NetworkPluginName  string

 	ClusterNetworkCIDR string

 	HostSubnetLength   uint

@@ -43,6 +43,15 @@ func init() {

 				obj.PodEvictionTimeout = "5m"

 			}

 		},

+		func(obj *NodeConfig) {

+			// Defaults/migrations for NetworkConfig

+			if len(obj.NetworkConfig.NetworkPluginName) == 0 {

+				obj.NetworkConfig.NetworkPluginName = obj.DeprecatedNetworkPluginName

+			}

+			if obj.NetworkConfig.MTU == 0 {

+				obj.NetworkConfig.MTU = 1450

+			}

+		},

 		func(obj *EtcdStorageConfig) {

 			if len(obj.KubernetesStorageVersion) == 0 {

 				obj.KubernetesStorageVersion = "v1"

@@ -89,6 +98,12 @@ func init() {

 		panic(err)

 	}

 	err = newer.Scheme.AddConversionFuncs(

+		func(in *NodeConfig, out *newer.NodeConfig, s conversion.Scope) error {

+			return s.DefaultConvert(in, out, conversion.IgnoreMissingFields)

+		},

+		func(in *newer.NodeConfig, out *NodeConfig, s conversion.Scope) error {

+			return s.DefaultConvert(in, out, conversion.IgnoreMissingFields)

+		},

 		func(in *ServingInfo, out *newer.ServingInfo, s conversion.Scope) error {

 			out.BindAddress = in.BindAddress

 			out.BindNetwork = in.BindNetwork

@@ -27,8 +27,11 @@ type NodeConfig struct {

 	// DNSIP holds the IP

 	DNSIP string `json:"dnsIP"`

-	// NetworkPluginName is a string specifying the networking plugin

-	NetworkPluginName string `json:"networkPluginName"`

+	// Deprecated and maintained for backward compatibility, use NetworkConfig.NetworkPluginName instead

+	DeprecatedNetworkPluginName string `json:"networkPluginName,omitempty"`

+

+	// NetworkConfig provides network options for the node

+	NetworkConfig NodeNetworkConfig `json:"networkConfig"`

 	// VolumeDirectory is the directory that volumes will be stored under

 	VolumeDirectory string `json:"volumeDirectory"`

@@ -52,6 +55,14 @@ type NodeConfig struct {

 	KubeletArguments ExtendedArguments `json:"kubeletArguments,omitempty"`

 }

+// NodeNetworkConfig provides network options for the node

+type NodeNetworkConfig struct {

+	// NetworkPluginName is a string specifying the networking plugin

+	NetworkPluginName string `json:"networkPluginName"`

+	// Maximum transmission unit for the network packets

+	MTU uint `json:"mtu"`

+}

+

 // DockerConfig holds Docker related configuration options.

 type DockerConfig struct {

 	// ExecHandlerName is the name of the handler to use for executing

@@ -150,7 +161,7 @@ type MasterConfig struct {

 	RoutingConfig RoutingConfig `json:"routingConfig"`

 	// NetworkConfig to be passed to the compiled in network plugin

-	NetworkConfig NetworkConfig `json:"networkConfig"`

+	NetworkConfig MasterNetworkConfig `json:"networkConfig"`

 }

 type ProjectConfig struct {

@@ -207,8 +218,8 @@ type RoutingConfig struct {

 	Subdomain string `json:"subdomain"`

 }

-// NetworkConfig to be passed to the compiled in network plugin

-type NetworkConfig struct {

+// MasterNetworkConfig to be passed to the compiled in network plugin

+type MasterNetworkConfig struct {

 	NetworkPluginName  string `json:"networkPluginName"`

 	ClusterNetworkCIDR string `json:"clusterNetworkCIDR"`

 	HostSubnetLength   uint   `json:"hostSubnetLength"`

@@ -26,7 +26,9 @@ imageConfig:

   latest: false

 kind: NodeConfig

 masterKubeConfig: ""

-networkPluginName: ""

+networkConfig:

+  mtu: 0

+  networkPluginName: ""

 nodeName: ""

 podManifestConfig:

   fileCheckIntervalSeconds: 0

@@ -33,6 +33,8 @@ func ValidateNodeConfig(config *api.NodeConfig) fielderrors.ValidationErrorList

 		allErrs = append(allErrs, ValidatePodManifestConfig(config.PodManifestConfig).Prefix("podManifestConfig")...)

 	}

+	allErrs = append(allErrs, ValidateNetworkConfig(config.NetworkConfig).Prefix("networkConfig")...)

+

 	allErrs = append(allErrs, ValidateDockerConfig(config.DockerConfig).Prefix("dockerConfig")...)

 	allErrs = append(allErrs, ValidateKubeletExtendedArguments(config.KubeletArguments).Prefix("kubeletArguments")...)

@@ -40,6 +42,17 @@ func ValidateNodeConfig(config *api.NodeConfig) fielderrors.ValidationErrorList

 	return allErrs

 }

+func ValidateNetworkConfig(config api.NodeNetworkConfig) fielderrors.ValidationErrorList {

+	allErrs := fielderrors.ValidationErrorList{}

+

+	if len(config.NetworkPluginName) > 0 {

+		if config.MTU == 0 {

+			allErrs = append(allErrs, fielderrors.NewFieldInvalid("mtu", config.MTU, fmt.Sprintf("must be greater than zero")))

+		}

+	}

+	return allErrs

+}

+

 func ValidateDockerConfig(config api.DockerConfig) fielderrors.ValidationErrorList {

 	allErrs := fielderrors.ValidationErrorList{}

@@ -112,7 +112,7 @@ func BuildKubernetesNodeConfig(options configapi.NodeConfig) (*NodeConfig, error

 	server.HealthzPort = 0  // no unsecured healthz access

 	server.ClusterDNS = dnsIP

 	server.ClusterDomain = options.DNSDomain

-	server.NetworkPluginName = options.NetworkPluginName

+	server.NetworkPluginName = options.NetworkConfig.NetworkPluginName

 	server.HostNetworkSources = strings.Join([]string{kubelet.ApiserverSource, kubelet.FileSource}, ",")

 	server.HTTPCheckFrequency = 0 // no remote HTTP pod creation access

 	server.FileCheckFrequency = time.Duration(fileCheckInterval) * time.Second

@@ -240,7 +240,7 @@ func (args MasterArgs) BuildSerializeableMasterConfig() (*configapi.MasterConfig

 			SecurityAllocator: &configapi.SecurityAllocator{},

 		},

-		NetworkConfig: configapi.NetworkConfig{

+		NetworkConfig: configapi.MasterNetworkConfig{

 			NetworkPluginName:  args.NetworkArgs.NetworkPluginName,

 			ClusterNetworkCIDR: args.NetworkArgs.ClusterNetworkCIDR,

 			HostSubnetLength:   args.NetworkArgs.HostSubnetLength,

@@ -120,7 +120,9 @@ func (args NodeArgs) BuildSerializeableNodeConfig() (*configapi.NodeConfig, erro

 			Latest: args.ImageFormatArgs.ImageTemplate.Latest,

 		},

-		NetworkPluginName: args.NetworkPluginName,

+		NetworkConfig: configapi.NodeNetworkConfig{

+			NetworkPluginName: args.NetworkPluginName,

+		},

 		VolumeDirectory:     args.VolumeDir,

 		AllowDisabledDocker: args.AllowDisabledDocker,

@@ -245,17 +245,17 @@ func RunSDNController(config *kubernetes.NodeConfig, nodeConfig configapi.NodeCo

 		glog.Fatal("Failed to get kube client for SDN")

 	}

-	switch nodeConfig.NetworkPluginName {

+	switch nodeConfig.NetworkConfig.NetworkPluginName {

 	case flatsdn.NetworkPluginName():

 		ch := make(chan struct{})

 		config.KubeletConfig.StartUpdates = ch

-		go flatsdn.Node(oclient, config.Client, nodeConfig.NodeName, "", ch)

+		go flatsdn.Node(oclient, config.Client, nodeConfig.NodeName, "", ch, nodeConfig.NetworkConfig.MTU)

 	case multitenant.NetworkPluginName():

 		ch := make(chan struct{})

 		config.KubeletConfig.StartUpdates = ch

 		plugin := multitenant.GetKubeNetworkPlugin()

 		config.KubeletConfig.NetworkPlugins = append(config.KubeletConfig.NetworkPlugins, plugin)

-		go multitenant.Node(oclient, config.Client, nodeConfig.NodeName, "", ch, plugin)

+		go multitenant.Node(oclient, config.Client, nodeConfig.NodeName, "", ch, plugin, nodeConfig.NetworkConfig.MTU)

 	}

 }

@@ -36,13 +36,13 @@ func Master(osClient *osclient.Client, kClient *kclient.Client, clusterNetwork s

 	}

 }

-func Node(osClient *osclient.Client, kClient *kclient.Client, hostname string, publicIP string, ready chan struct{}) {

+func Node(osClient *osclient.Client, kClient *kclient.Client, hostname string, publicIP string, ready chan struct{}, mtu uint) {

 	osdnInterface := osdn.NewOsdnRegistryInterface(osClient, kClient)

 	kc, err := ovssubnet.NewKubeController(&osdnInterface, hostname, publicIP, ready)

 	if err != nil {

 		glog.Fatalf("SDN initialization failed: %v", err)

 	}

-	err = kc.StartNode(false, false)

+	err = kc.StartNode(false, false, mtu)

 	if err != nil {

 		glog.Fatalf("SDN Node failed: %v", err)

 	}

@@ -37,7 +37,7 @@ func Master(osClient *osclient.Client, kClient *kclient.Client, clusterNetwork s

 	}

 }

-func Node(osClient *osclient.Client, kClient *kclient.Client, hostname string, publicIP string, ready chan struct{}, plugin knetwork.NetworkPlugin) {

+func Node(osClient *osclient.Client, kClient *kclient.Client, hostname string, publicIP string, ready chan struct{}, plugin knetwork.NetworkPlugin, mtu uint) {

 	mp, ok := plugin.(*MultitenantPlugin)

 	if !ok {

 		glog.Fatalf("Failed to type cast provided plugin to a multitenant type plugin")

@@ -48,7 +48,7 @@ func Node(osClient *osclient.Client, kClient *kclient.Client, hostname string, p

 		glog.Fatalf("SDN initialization failed: %v", err)

 	}

 	mp.OvsController = kc

-	err = kc.StartNode(false, false)

+	err = kc.StartNode(false, false, mtu)

 	if err != nil {

 		glog.Fatalf("SDN Node failed: %v", err)

 	}