diff --git a/build/yamls/antrea-aks.yml b/build/yamls/antrea-aks.yml
index b9931e8841f..7424edfe718 100644
--- a/build/yamls/antrea-aks.yml
+++ b/build/yamls/antrea-aks.yml
@@ -3052,6 +3052,7 @@ rules:
   - get
   - watch
   - list
+  - patch
 - apiGroups:
   - ""
   resources:
diff --git a/build/yamls/antrea-eks.yml b/build/yamls/antrea-eks.yml
index 7b3a1da5815..78c20700499 100644
--- a/build/yamls/antrea-eks.yml
+++ b/build/yamls/antrea-eks.yml
@@ -3052,6 +3052,7 @@ rules:
   - get
   - watch
   - list
+  - patch
 - apiGroups:
   - ""
   resources:
diff --git a/build/yamls/antrea-gke.yml b/build/yamls/antrea-gke.yml
index efaeb679b3b..d9eba3e588d 100644
--- a/build/yamls/antrea-gke.yml
+++ b/build/yamls/antrea-gke.yml
@@ -3052,6 +3052,7 @@ rules:
   - get
   - watch
   - list
+  - patch
 - apiGroups:
   - ""
   resources:
diff --git a/build/yamls/antrea-ipsec.yml b/build/yamls/antrea-ipsec.yml
index 75c545384ae..0472cbde9ba 100644
--- a/build/yamls/antrea-ipsec.yml
+++ b/build/yamls/antrea-ipsec.yml
@@ -3052,6 +3052,7 @@ rules:
   - get
   - watch
   - list
+  - patch
 - apiGroups:
   - ""
   resources:
diff --git a/build/yamls/antrea.yml b/build/yamls/antrea.yml
index 80a6d0d6386..126159898a3 100644
--- a/build/yamls/antrea.yml
+++ b/build/yamls/antrea.yml
@@ -3052,6 +3052,7 @@ rules:
   - get
   - watch
   - list
+  - patch
 - apiGroups:
   - ""
   resources:
diff --git a/build/yamls/base/agent-rbac.yml b/build/yamls/base/agent-rbac.yml
index d1b900d573e..13c94107750 100644
--- a/build/yamls/base/agent-rbac.yml
+++ b/build/yamls/base/agent-rbac.yml
@@ -18,6 +18,7 @@ rules:
       - get
       - watch
       - list
+      - patch
   - apiGroups:
       - ""
     resources:
diff --git a/pkg/agent/agent.go b/pkg/agent/agent.go
index a29fa056d86..b99a0c79040 100644
--- a/pkg/agent/agent.go
+++ b/pkg/agent/agent.go
@@ -16,6 +16,7 @@ package agent
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"net"
 	"os"
@@ -25,8 +26,10 @@ import (
 
 	"github.com/containernetworking/plugins/pkg/ip"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	apitypes "k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/wait"
 	clientset "k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/util/retry"
 	"k8s.io/klog/v2"
 
 	"antrea.io/antrea/pkg/agent/cniserver"
@@ -53,6 +56,9 @@ const (
 	maxRetryForRoundNumSave = 5
 )
 
+// getIPNetDeviceFromIP is meant to be overridden for testing.
+var getIPNetDeviceFromIP = util.GetIPNetDeviceFromIP
+
 // Initializer knows how to setup host networking, OpenVSwitch, and Openflow.
 type Initializer struct {
 	client          clientset.Interface
@@ -637,11 +643,31 @@ func (i *Initializer) initNodeLocalConfig() error {
 
 	ipAddr, err := noderoute.GetNodeAddr(node)
 	if err != nil {
-		return fmt.Errorf("failed to obtain local IP address from k8s: %w", err)
+		return fmt.Errorf("failed to obtain local IP address from K8s: %w", err)
 	}
-	localAddr, localIntf, err := util.GetIPNetDeviceFromIP(ipAddr)
+	localAddr, localIntf, err := getIPNetDeviceFromIP(ipAddr)
 	if err != nil {
-		return fmt.Errorf("failed to get local IPNet:  %v", err)
+		return fmt.Errorf("failed to get local IPNet device with IP %v: %v", ipAddr, err)
+	}
+
+	// Update the Node's MAC address in the annotations of the Node. The MAC address will be used for direct routing by
+	// OVS in noencap case on Windows Nodes. As a mixture of Linux and Windows nodes is possible, Linux Nodes' MAC
+	// addresses should be reported too to make them discoverable for Windows Nodes.
+	if i.networkConfig.TrafficEncapMode.SupportsNoEncap() {
+		klog.Infof("Updating Node MAC annotation")
+		patch, _ := json.Marshal(map[string]interface{}{
+			"metadata": map[string]interface{}{
+				"annotations": map[string]string{
+					types.NodeMACAddressAnnotationKey: localIntf.HardwareAddr.String(),
+				},
+			},
+		})
+		if err := retry.RetryOnConflict(retry.DefaultRetry, func() error {
+			_, err := i.client.CoreV1().Nodes().Patch(context.TODO(), nodeName, apitypes.MergePatchType, patch, metav1.PatchOptions{})
+			return err
+		}); err != nil {
+			return err
+		}
 	}
 
 	i.nodeConfig = &config.NodeConfig{
diff --git a/pkg/agent/agent_test.go b/pkg/agent/agent_test.go
index 8eff9ae08ef..298af4ca3d9 100644
--- a/pkg/agent/agent_test.go
+++ b/pkg/agent/agent_test.go
@@ -15,19 +15,27 @@
 package agent
 
 import (
+	"context"
 	"fmt"
 	"net"
+	"os"
 	"testing"
 
 	mock "github.com/golang/mock/gomock"
 	"github.com/google/uuid"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes/fake"
 
 	"antrea.io/antrea/pkg/agent/cniserver"
 	"antrea.io/antrea/pkg/agent/config"
 	"antrea.io/antrea/pkg/agent/interfacestore"
+	"antrea.io/antrea/pkg/agent/types"
 	"antrea.io/antrea/pkg/ovs/ovsconfig"
 	ovsconfigtest "antrea.io/antrea/pkg/ovs/ovsconfig/testing"
+	"antrea.io/antrea/pkg/util/env"
 )
 
 func newAgentInitializer(ovsBridgeClient ovsconfig.OVSBridgeClient, ifaceStore interfacestore.InterfaceStore) *Initializer {
@@ -134,3 +142,120 @@ func TestGetRoundInfo(t *testing.T) {
 	roundInfo = getRoundInfo(mockOVSBridgeClient)
 	assert.Equal(t, uint64(initialRoundNum), roundInfo.RoundNum, "Unexpected round number")
 }
+
+func TestInitNodeLocalConfig(t *testing.T) {
+	nodeName := "node1"
+	ovsBridge := "br-int"
+	nodeIPStr := "192.168.10.10"
+	_, nodeIPNet, _ := net.ParseCIDR("192.168.10.10/24")
+	macAddr, _ := net.ParseMAC("00:00:5e:00:53:01")
+	ipDevice := &net.Interface{
+		Index:        10,
+		MTU:          1500,
+		Name:         "ens160",
+		HardwareAddr: macAddr,
+	}
+	podCIDRStr := "172.16.10.0/24"
+	_, podCIDR, _ := net.ParseCIDR(podCIDRStr)
+	tests := []struct {
+		name                   string
+		trafficEncapMode       config.TrafficEncapModeType
+		tunnelType             ovsconfig.TunnelType
+		mtu                    int
+		expectedMTU            int
+		expectedNodeAnnotation map[string]string
+	}{
+		{
+			name:                   "noencap mode",
+			trafficEncapMode:       config.TrafficEncapModeNoEncap,
+			mtu:                    0,
+			expectedMTU:            1500,
+			expectedNodeAnnotation: map[string]string{types.NodeMACAddressAnnotationKey: macAddr.String()},
+		},
+		{
+			name:                   "hybrid mode",
+			trafficEncapMode:       config.TrafficEncapModeHybrid,
+			mtu:                    0,
+			expectedMTU:            1500,
+			expectedNodeAnnotation: map[string]string{types.NodeMACAddressAnnotationKey: macAddr.String()},
+		},
+		{
+			name:                   "encap mode, geneve tunnel",
+			trafficEncapMode:       config.TrafficEncapModeEncap,
+			tunnelType:             ovsconfig.GeneveTunnel,
+			mtu:                    0,
+			expectedMTU:            1450,
+			expectedNodeAnnotation: nil,
+		},
+		{
+			name:                   "encap mode, mtu specified",
+			trafficEncapMode:       config.TrafficEncapModeEncap,
+			tunnelType:             ovsconfig.GeneveTunnel,
+			mtu:                    1400,
+			expectedMTU:            1400,
+			expectedNodeAnnotation: nil,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			node := &corev1.Node{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: nodeName,
+				},
+				Spec: corev1.NodeSpec{
+					PodCIDR: podCIDRStr,
+				},
+				Status: corev1.NodeStatus{
+					Addresses: []corev1.NodeAddress{
+						{
+							Type:    corev1.NodeInternalIP,
+							Address: nodeIPStr,
+						},
+					},
+				},
+			}
+			client := fake.NewSimpleClientset(node)
+			ifaceStore := interfacestore.NewInterfaceStore()
+			defer mockGetIPNetDeviceFromIP(nodeIPNet, ipDevice)()
+			defer mockNodeNameEnv(nodeName)()
+
+			initializer := &Initializer{
+				client:     client,
+				ifaceStore: ifaceStore,
+				mtu:        tt.mtu,
+				ovsBridge:  ovsBridge,
+				networkConfig: &config.NetworkConfig{
+					TrafficEncapMode: tt.trafficEncapMode,
+					TunnelType:       tt.tunnelType,
+				},
+			}
+			require.NoError(t, initializer.initNodeLocalConfig())
+			expectedNodeConfig := config.NodeConfig{
+				Name:            nodeName,
+				OVSBridge:       ovsBridge,
+				DefaultTunName:  defaultTunInterfaceName,
+				PodIPv4CIDR:     podCIDR,
+				NodeIPAddr:      nodeIPNet,
+				NodeMTU:         tt.expectedMTU,
+				UplinkNetConfig: new(config.AdapterNetConfig),
+			}
+			assert.Equal(t, expectedNodeConfig, *initializer.nodeConfig)
+			node, err := client.CoreV1().Nodes().Get(context.TODO(), nodeName, metav1.GetOptions{})
+			require.NoError(t, err)
+			assert.Equal(t, tt.expectedNodeAnnotation, node.Annotations)
+		})
+	}
+}
+
+func mockGetIPNetDeviceFromIP(ipNet *net.IPNet, ipDevice *net.Interface) func() {
+	prevGetIPNetDeviceFromIP := getIPNetDeviceFromIP
+	getIPNetDeviceFromIP = func(localIP net.IP) (*net.IPNet, *net.Interface, error) {
+		return ipNet, ipDevice, nil
+	}
+	return func() { getIPNetDeviceFromIP = prevGetIPNetDeviceFromIP }
+}
+
+func mockNodeNameEnv(name string) func() {
+	_ = os.Setenv(env.NodeNameEnvKey, name)
+	return func() { os.Unsetenv(env.NodeNameEnvKey) }
+}
diff --git a/pkg/agent/agent_windows.go b/pkg/agent/agent_windows.go
index 9f3b3d4052a..2b93af516e5 100644
--- a/pkg/agent/agent_windows.go
+++ b/pkg/agent/agent_windows.go
@@ -71,7 +71,7 @@ func (i *Initializer) prepareHostNetwork() error {
 	// Create HNS network.
 	subnetCIDR := i.nodeConfig.PodIPv4CIDR
 	if subnetCIDR == nil {
-		return fmt.Errorf("Failed to find valid IPv4 PodCIDR")
+		return fmt.Errorf("failed to find valid IPv4 PodCIDR")
 	}
 	return util.PrepareHNSNetwork(subnetCIDR, i.nodeConfig.NodeIPAddr, adapter)
 }
@@ -82,7 +82,7 @@ func (i *Initializer) prepareOVSBridge() error {
 	hnsNetwork, err := hcsshim.GetHNSNetworkByName(util.LocalHNSNetwork)
 	defer func() {
 		// prepareOVSBridge only works on windows platform. The operation has a chance to fail on the first time agent
-		// starts up when OVS bridge uplink and local inteface have not been configured. If the operation fails, the
+		// starts up when OVS bridge uplink and local interface have not been configured. If the operation fails, the
 		// host can not communicate with external network. To make sure the agent can connect to API server in
 		// next retry, this step deletes OVS bridge and HNS network created previously which will restore the
 		// host network.
@@ -144,7 +144,7 @@ func (i *Initializer) prepareOVSBridge() error {
 
 	// Move network configuration of uplink interface to OVS bridge local interface.
 	// - The net configuration of uplink will be restored by OS if the attached HNS network is deleted.
-	// - When ovs-switchd is down, antrea-agent will disable OVS Extension. The OVS bridge local interface will work
+	// - When ovs-vswitchd is down, antrea-agent will disable OVS Extension. The OVS bridge local interface will work
 	//   like a normal interface on host and is responsible for forwarding host traffic.
 	if err = util.EnableHostInterface(brName); err != nil {
 		return err
diff --git a/pkg/agent/types/annotations.go b/pkg/agent/types/annotations.go
new file mode 100644
index 00000000000..c835cb34e10
--- /dev/null
+++ b/pkg/agent/types/annotations.go
@@ -0,0 +1,20 @@
+// Copyright 2021 Antrea Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package types
+
+const (
+	// NodeMACAddressAnnotationKey represents the key of the Node's MAC address in the Annotations of the Node.
+	NodeMACAddressAnnotationKey string = "node.antrea.io/mac-address"
+)
diff --git a/pkg/agent/util/net_windows.go b/pkg/agent/util/net_windows.go
index d8223f66d29..c95cd1a0d34 100644
--- a/pkg/agent/util/net_windows.go
+++ b/pkg/agent/util/net_windows.go
@@ -400,7 +400,7 @@ func GetLocalBroadcastIP(ipNet *net.IPNet) net.IP {
 	return lastAddr
 }
 
-// GetDefaultGatewayByInterfaceIndex returns the default gateway configured on the speicified interface.
+// GetDefaultGatewayByInterfaceIndex returns the default gateway configured on the specified interface.
 func GetDefaultGatewayByInterfaceIndex(ifIndex int) (string, error) {
 	cmd := fmt.Sprintf("$(Get-NetRoute -InterfaceIndex %d -DestinationPrefix 0.0.0.0/0 ).NextHop", ifIndex)
 	defaultGW, err := CallPSCommand(cmd)
diff --git a/pkg/util/env/env.go b/pkg/util/env/env.go
index 253768d8754..e37606b6abe 100644
--- a/pkg/util/env/env.go
+++ b/pkg/util/env/env.go
@@ -21,9 +21,9 @@ import (
 	"k8s.io/klog/v2"
 )
 
-// nodeNameEnvKey is environment variable.
+// NodeNameEnvKey is environment variable.
 const (
-	nodeNameEnvKey     = "NODE_NAME"
+	NodeNameEnvKey     = "NODE_NAME"
 	podNameEnvKey      = "POD_NAME"
 	podNamespaceEnvKey = "POD_NAMESPACE"
 	svcAcctNameEnvKey  = "SERVICEACCOUNT_NAME"
@@ -37,11 +37,11 @@ const (
 // - Environment variable NODE_NAME, which should be set by Downward API
 // - OS's hostname
 func GetNodeName() (string, error) {
-	nodeName := os.Getenv(nodeNameEnvKey)
+	nodeName := os.Getenv(NodeNameEnvKey)
 	if nodeName != "" {
 		return nodeName, nil
 	}
-	klog.Infof("Environment variable %s not found, using hostname instead", nodeNameEnvKey)
+	klog.Infof("Environment variable %s not found, using hostname instead", NodeNameEnvKey)
 	var err error
 	nodeName, err = os.Hostname()
 	if err != nil {
diff --git a/pkg/util/env/env_test.go b/pkg/util/env/env_test.go
index 8e76eab83ff..960ec62ad49 100644
--- a/pkg/util/env/env_test.go
+++ b/pkg/util/env/env_test.go
@@ -39,8 +39,8 @@ func TestGetNodeName(t *testing.T) {
 
 func compareNodeName(k, v string, t *testing.T) {
 	if k != "" {
-		_ = os.Setenv(nodeNameEnvKey, k)
-		defer os.Unsetenv(nodeNameEnvKey)
+		_ = os.Setenv(NodeNameEnvKey, k)
+		defer os.Unsetenv(NodeNameEnvKey)
 	}
 	nodeName, err := GetNodeName()
 	if err != nil {