diff --git a/src/main/java/org/opencord/dhcpl2relay/DhcpL2Relay.java b/src/main/java/org/opencord/dhcpl2relay/DhcpL2Relay.java
index cdffe4e..a3c8e4b 100755
--- a/src/main/java/org/opencord/dhcpl2relay/DhcpL2Relay.java
+++ b/src/main/java/org/opencord/dhcpl2relay/DhcpL2Relay.java
@@ -17,6 +17,7 @@
 
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
 
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
@@ -31,11 +32,15 @@
 import org.onlab.packet.DHCPPacketType;
 import org.onlab.packet.Ethernet;
 import org.onlab.packet.IPv4;
-import org.onlab.packet.Ip4Address;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.TpPort;
 import org.onlab.packet.UDP;
 import org.onlab.packet.VlanId;
+import org.onosproject.mastership.MastershipEvent;
+import org.onosproject.mastership.MastershipListener;
+import org.onosproject.mastership.MastershipService;
+import org.onosproject.net.device.DeviceEvent;
+import org.onosproject.net.device.DeviceListener;
 import org.opencord.dhcpl2relay.packet.DhcpEthernet;
 import org.opencord.dhcpl2relay.packet.DhcpOption82;
 import org.onlab.util.Tools;
@@ -72,8 +77,8 @@
 import java.nio.ByteBuffer;
 import java.util.Dictionary;
 import java.util.List;
-import java.util.Optional;
 import java.util.Set;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.stream.Collectors;
 
 import static org.onlab.packet.DHCP.DHCPOptionCode.OptionCode_MessageType;
@@ -123,6 +128,9 @@
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     protected DeviceService deviceService;
 
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected MastershipService mastershipService;
+
     @Property(name = "option82", boolValue = true,
             label = "Add option 82 to relayed packets")
     protected boolean option82 = true;
@@ -130,8 +138,12 @@
     private DhcpRelayPacketProcessor dhcpRelayPacketProcessor =
             new DhcpRelayPacketProcessor();
 
+    private InnerMastershipListener changeListener = new InnerMastershipListener();
+    private InnerDeviceListener deviceListener = new InnerDeviceListener();
 
-    private ConnectPoint dhcpServerConnectPoint = null;
+    // connect points to the DHCP server
+    Set<ConnectPoint> dhcpConnectPoints;
+    private AtomicReference<ConnectPoint> dhcpServerConnectPoint = new AtomicReference<>();
     private MacAddress dhcpConnectMac = MacAddress.BROADCAST;
     private ApplicationId appId;
 
@@ -142,6 +154,9 @@
         componentConfigService.registerProperties(getClass());
 
         cfgService.addListener(cfgListener);
+        mastershipService.addListener(changeListener);
+        deviceService.addListener(deviceListener);
+
         factories.forEach(cfgService::registerConfigFactory);
         //update the dhcp server configuration.
         updateConfig();
@@ -185,23 +200,49 @@
      * @return true if all information we need have been initialized
      */
     private boolean configured() {
-        return dhcpServerConnectPoint != null;
+        return dhcpServerConnectPoint.get() != null;
     }
 
+    /**
+     * Selects a connect point through an available device for which it is the master.
+     */
+    private void selectServerConnectPoint() {
+        synchronized (this) {
+            dhcpServerConnectPoint.set(null);
+            if (dhcpConnectPoints != null) {
+                // find a connect point through a device for which we are master
+                for (ConnectPoint cp: dhcpConnectPoints) {
+                    if (mastershipService.isLocalMaster(cp.deviceId())) {
+                        if (deviceService.isAvailable(cp.deviceId())) {
+                            dhcpServerConnectPoint.set(cp);
+                        }
+                        log.info("DHCP connectPoint selected is {}", cp);
+                        break;
+                    }
+                }
+            }
+
+            log.info("DHCP Server connectPoint is {}", dhcpServerConnectPoint.get());
+
+            if (dhcpServerConnectPoint.get() == null) {
+                log.error("Master of none, can't relay DHCP Message to server");
+            }
+        }
+    }
+
+    /**
+     * Updates the network configuration.
+     */
     private void updateConfig() {
         DhcpL2RelayConfig cfg = cfgService.getConfig(appId, DhcpL2RelayConfig.class);
         if (cfg == null) {
             log.warn("Dhcp Server info not available");
             return;
         }
-        if (dhcpServerConnectPoint == null) {
-            dhcpServerConnectPoint = cfg.getDhcpServerConnectPoint();
-            requestDhcpPackets();
-        } else {
-            cancelDhcpPackets();
-            dhcpServerConnectPoint = cfg.getDhcpServerConnectPoint();
-            requestDhcpPackets();
-        }
+
+        dhcpConnectPoints = Sets.newConcurrentHashSet(cfg.getDhcpServerConnectPoint());
+
+        selectServerConnectPoint();
 
         log.info("dhcp server connect point: " + dhcpServerConnectPoint);
     }
@@ -210,44 +251,39 @@
      * Request DHCP packet in via PacketService.
      */
     private void requestDhcpPackets() {
-        if (dhcpServerConnectPoint != null) {
-            TrafficSelector.Builder selectorServer = DefaultTrafficSelector.builder()
-                    .matchEthType(Ethernet.TYPE_IPV4)
-                    .matchIPProtocol(IPv4.PROTOCOL_UDP)
-                    .matchUdpSrc(TpPort.tpPort(UDP.DHCP_SERVER_PORT));
-            packetService.requestPackets(selectorServer.build(),
-                    PacketPriority.CONTROL, appId,
-                    Optional.of(dhcpServerConnectPoint.deviceId()));
+        TrafficSelector.Builder selectorServer = DefaultTrafficSelector.builder()
+                .matchEthType(Ethernet.TYPE_IPV4)
+                .matchIPProtocol(IPv4.PROTOCOL_UDP)
+                .matchUdpSrc(TpPort.tpPort(UDP.DHCP_SERVER_PORT));
+        packetService.requestPackets(selectorServer.build(),
+                PacketPriority.CONTROL, appId);
 
-            TrafficSelector.Builder selectorClient = DefaultTrafficSelector.builder()
-                    .matchEthType(Ethernet.TYPE_IPV4)
-                    .matchIPProtocol(IPv4.PROTOCOL_UDP)
-                    .matchUdpSrc(TpPort.tpPort(UDP.DHCP_CLIENT_PORT));
-            packetService.requestPackets(selectorClient.build(),
-                    PacketPriority.CONTROL, appId,
-                    Optional.of(dhcpServerConnectPoint.deviceId()));
-        }
+        TrafficSelector.Builder selectorClient = DefaultTrafficSelector.builder()
+                .matchEthType(Ethernet.TYPE_IPV4)
+                .matchIPProtocol(IPv4.PROTOCOL_UDP)
+                .matchUdpSrc(TpPort.tpPort(UDP.DHCP_CLIENT_PORT));
+        packetService.requestPackets(selectorClient.build(),
+                PacketPriority.CONTROL, appId);
+
     }
 
     /**
      * Cancel requested DHCP packets in via packet service.
      */
     private void cancelDhcpPackets() {
-        if (dhcpServerConnectPoint != null) {
-            TrafficSelector.Builder selectorServer = DefaultTrafficSelector.builder()
-                    .matchEthType(Ethernet.TYPE_IPV4)
-                    .matchIPProtocol(IPv4.PROTOCOL_UDP)
-                    .matchUdpSrc(TpPort.tpPort(UDP.DHCP_SERVER_PORT));
-            packetService.cancelPackets(selectorServer.build(),
-                    PacketPriority.CONTROL, appId, Optional.of(dhcpServerConnectPoint.deviceId()));
+        TrafficSelector.Builder selectorServer = DefaultTrafficSelector.builder()
+                .matchEthType(Ethernet.TYPE_IPV4)
+                .matchIPProtocol(IPv4.PROTOCOL_UDP)
+                .matchUdpSrc(TpPort.tpPort(UDP.DHCP_SERVER_PORT));
+        packetService.cancelPackets(selectorServer.build(),
+                PacketPriority.CONTROL, appId);
 
-            TrafficSelector.Builder selectorClient = DefaultTrafficSelector.builder()
-                    .matchEthType(Ethernet.TYPE_IPV4)
-                    .matchIPProtocol(IPv4.PROTOCOL_UDP)
-                    .matchUdpSrc(TpPort.tpPort(UDP.DHCP_CLIENT_PORT));
-            packetService.cancelPackets(selectorClient.build(),
-                    PacketPriority.CONTROL, appId, Optional.of(dhcpServerConnectPoint.deviceId()));
-        }
+        TrafficSelector.Builder selectorClient = DefaultTrafficSelector.builder()
+                .matchEthType(Ethernet.TYPE_IPV4)
+                .matchIPProtocol(IPv4.PROTOCOL_UDP)
+                .matchUdpSrc(TpPort.tpPort(UDP.DHCP_CLIENT_PORT));
+        packetService.cancelPackets(selectorClient.build(),
+                PacketPriority.CONTROL, appId);
     }
 
     private SubscriberAndDeviceInformation getDevice(PacketContext context) {
@@ -263,16 +299,6 @@
 
         return subsService.get(serialNo);
     }
-    private Ip4Address relayAgentIPv4Address(ConnectPoint cp) {
-
-        SubscriberAndDeviceInformation device = getDevice(cp);
-        if (device == null) {
-            log.warn("Device not found for {}", cp);
-            return null;
-        }
-
-        return device.ipAddress();
-    }
 
     private MacAddress relayAgentMacAddress(PacketContext context) {
 
@@ -287,7 +313,11 @@
     }
 
     private String nasPortId(PacketContext context) {
-        Port p = deviceService.getPort(context.inPacket().receivedFrom());
+        return nasPortId(context.inPacket().receivedFrom());
+    }
+
+    private String nasPortId(ConnectPoint cp) {
+        Port p = deviceService.getPort(cp);
         return p.annotations().value(AnnotationKeys.PORT_NAME);
     }
 
@@ -305,6 +335,26 @@
         return sub.cTag();
     }
 
+    private VlanId cTag(ConnectPoint cp) {
+        String portId = nasPortId(cp);
+        SubscriberAndDeviceInformation sub = subsService.get(portId);
+        if (sub == null) {
+            log.warn("Subscriber info not found for {} looking for C-TAG", cp);
+            return VlanId.NONE;
+        }
+        return sub.cTag();
+    }
+
+    private VlanId sTag(ConnectPoint cp) {
+        String portId = nasPortId(cp);
+        SubscriberAndDeviceInformation sub = subsService.get(portId);
+        if (sub == null) {
+            log.warn("Subscriber info not found for {} looking for S-TAG", cp);
+            return VlanId.NONE;
+        }
+        return sub.sTag();
+    }
+
     private VlanId sTag(PacketContext context) {
         SubscriberAndDeviceInformation sub = getSubscriber(context);
         if (sub == null) {
@@ -358,15 +408,15 @@
         //forward the packet to ConnectPoint where the DHCP server is attached.
         private void forwardPacket(DhcpEthernet packet) {
 
-            if (dhcpServerConnectPoint != null) {
+            if (dhcpServerConnectPoint.get() != null) {
                 TrafficTreatment t = DefaultTrafficTreatment.builder()
-                        .setOutput(dhcpServerConnectPoint.port()).build();
+                        .setOutput(dhcpServerConnectPoint.get().port()).build();
                 OutboundPacket o = new DefaultOutboundPacket(
-                        dhcpServerConnectPoint.deviceId(), t,
+                        dhcpServerConnectPoint.get().deviceId(), t,
                         ByteBuffer.wrap(packet.serialize()));
                 if (log.isTraceEnabled()) {
                 log.trace("Relaying packet to dhcp server {} at {}",
-                        packet, dhcpServerConnectPoint);
+                        packet, dhcpServerConnectPoint.get());
                 }
                 packetService.emit(o);
             } else {
@@ -458,11 +508,12 @@
             etherReply.setSourceMacAddress(relayAgentMac);
             etherReply.setDestinationMacAddress(dhcpConnectMac);
 
+            etherReply.setPriorityCode(ethernetPacket.getPriorityCode());
             etherReply.setVlanID(cTag(context).toShort());
             etherReply.setQinQtpid(DhcpEthernet.TYPE_QINQ);
             etherReply.setQinQVid(sTag(context).toShort());
 
-            log.info("Finished processing packet");
+            log.info("Finished processing packet -- sending packet {}", etherReply);
             return etherReply;
         }
 
@@ -475,7 +526,6 @@
             UDP udpPacket = (UDP) ipv4Packet.getPayload();
             DHCP dhcpPayload = (DHCP) udpPacket.getPayload();
 
-
             MacAddress dstMac = valueOf(dhcpPayload.getClientHardwareAddress());
             Set<Host> hosts = hostService.getHostsByMac(dstMac);
             if (hosts == null || hosts.isEmpty()) {
@@ -490,28 +540,15 @@
             }
             Host host = hosts.iterator().next();
 
-            etherReply.setDestinationMacAddress(dstMac);
-            etherReply.setQinQVid(Ethernet.VLAN_UNTAGGED);
-            etherReply.setPriorityCode(ethernetPacket.getPriorityCode());
-            etherReply.setVlanID((short) 0);
+            ConnectPoint subsCp = new ConnectPoint(host.location().deviceId(),
+                    host.location().port());
 
             // we leave the srcMac from the original packet
+            etherReply.setDestinationMacAddress(dstMac);
+            etherReply.setQinQVid(sTag(subsCp).toShort());
+            etherReply.setPriorityCode(ethernetPacket.getPriorityCode());
+            etherReply.setVlanID((cTag(subsCp).toShort()));
 
-            // figure out the relay agent IP corresponding to the original request
-            Ip4Address relayAgentIP = relayAgentIPv4Address(
-                    new ConnectPoint(host.location().deviceId(),
-                            host.location().port()));
-            if (relayAgentIP == null) {
-                log.warn("Cannot determine relay agent Ipv4 addr for host {}. "
-                                + "Aborting relay for dhcp packet from server {}",
-                        host, ethernetPacket);
-                return null;
-            }
-
-            ipv4Packet.setSourceAddress(relayAgentIP.toInt());
-            ipv4Packet.setDestinationAddress(dhcpPayload.getYourIPAddress());
-
-            udpPacket.setDestinationPort(UDP.DHCP_CLIENT_PORT);
             if (option82) {
                 udpPacket.setPayload(removeOption82(dhcpPayload));
             } else {
@@ -561,6 +598,7 @@
 
         options.add(options.size() - 1, option);
         dhcpPacket.setOptions(options);
+
         return dhcpPacket;
 
     }
@@ -590,6 +628,58 @@
         }
     }
 
+    /**
+     * Handles Mastership changes for the devices which connect
+     * to the DHCP server.
+     */
+    private class InnerMastershipListener implements MastershipListener {
+        @Override
+        public void event(MastershipEvent event) {
+            if (dhcpServerConnectPoint.get() != null &&
+                    dhcpServerConnectPoint.get().deviceId().
+                            equals(event.subject())) {
+                log.trace("Mastership Event recevived for {}", event.subject());
+                // mastership of the device for our connect point has changed
+                // reselect
+                selectServerConnectPoint();
+            }
+        }
+    }
 
-
+    /**
+     * Handles Device status change for the devices which connect
+     * to the DHCP server.
+     */
+    private class InnerDeviceListener implements DeviceListener {
+        @Override
+        public void event(DeviceEvent event) {
+            log.trace("Device Event recevived for {} event {}", event.subject(), event.type());
+            if (dhcpServerConnectPoint.get() == null) {
+                switch (event.type()) {
+                    case DEVICE_ADDED:
+                    case DEVICE_AVAILABILITY_CHANGED:
+                        // some device is available check if we can get one
+                        selectServerConnectPoint();
+                        break;
+                    default:
+                        break;
+                }
+                return;
+            }
+            if (dhcpServerConnectPoint.get().deviceId().
+                    equals(event.subject().id())) {
+                switch (event.type()) {
+                    case DEVICE_AVAILABILITY_CHANGED:
+                    case DEVICE_REMOVED:
+                    case DEVICE_SUSPENDED:
+                        // state of our device has changed, check if we need
+                        // to re-select
+                        selectServerConnectPoint();
+                        break;
+                    default:
+                        break;
+                }
+            }
+        }
+    }
 }
diff --git a/src/main/java/org/opencord/dhcpl2relay/DhcpL2RelayConfig.java b/src/main/java/org/opencord/dhcpl2relay/DhcpL2RelayConfig.java
index c263149..eb60c7f 100755
--- a/src/main/java/org/opencord/dhcpl2relay/DhcpL2RelayConfig.java
+++ b/src/main/java/org/opencord/dhcpl2relay/DhcpL2RelayConfig.java
@@ -15,32 +15,59 @@
  */
 package org.opencord.dhcpl2relay;
 
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+
+import com.google.common.collect.ImmutableSet;
+
 import org.onosproject.core.ApplicationId;
 import org.onosproject.net.ConnectPoint;
 import org.onosproject.net.config.Config;
 
-import static org.onosproject.net.config.Config.FieldPresence.MANDATORY;
+import java.util.HashSet;
+import java.util.Set;
+
 
 /**
  * DHCP Relay Config class.
  */
 public class DhcpL2RelayConfig extends Config<ApplicationId> {
 
-    private static final String DHCP_CONNECT_POINT = "dhcpserverConnectPoint";
+    private static final String DHCP_CONNECT_POINTS = "dhcpServerConnectPoints";
 
     @Override
     public boolean isValid() {
 
-        return hasOnlyFields(DHCP_CONNECT_POINT) &&
-                isConnectPoint(DHCP_CONNECT_POINT, MANDATORY);
+        return hasOnlyFields(DHCP_CONNECT_POINTS);
     }
 
     /**
-     * Returns the dhcp server connect point.
+     * Returns the dhcp server connect points.
      *
-     * @return dhcp server connect point
+     * @return dhcp server connect points
      */
-    public ConnectPoint getDhcpServerConnectPoint() {
-        return ConnectPoint.deviceConnectPoint(object.path(DHCP_CONNECT_POINT).asText());
+    public Set<ConnectPoint> getDhcpServerConnectPoint() {
+        if (object == null) {
+            return new HashSet<ConnectPoint>();
+        }
+
+        if (!object.has(DHCP_CONNECT_POINTS)) {
+            return ImmutableSet.of();
+        }
+
+        ImmutableSet.Builder<ConnectPoint> builder = ImmutableSet.builder();
+        ArrayNode arrayNode = (ArrayNode) object.path(DHCP_CONNECT_POINTS);
+        for (JsonNode jsonNode : arrayNode) {
+            String portName = jsonNode.asText(null);
+            if (portName == null) {
+                return null;
+            }
+            try {
+                builder.add(ConnectPoint.deviceConnectPoint(portName));
+            } catch (IllegalArgumentException e) {
+                return null;
+            }
+        }
+        return builder.build();
     }
 }
diff --git a/src/main/java/org/opencord/dhcpl2relay/packet/DhcpOption82.java b/src/main/java/org/opencord/dhcpl2relay/packet/DhcpOption82.java
index b673f94..7f39258 100644
--- a/src/main/java/org/opencord/dhcpl2relay/packet/DhcpOption82.java
+++ b/src/main/java/org/opencord/dhcpl2relay/packet/DhcpOption82.java
@@ -45,7 +45,7 @@
 
     /**
      * sets AgentRemoteId.
-     * @param value
+     * @param value   Value to be set
      */
     public void setAgentRemoteId(String value) {
         this.agentRemoteId = value;
diff --git a/src/test/java/org/opencord/dhcpl2relay/DhcpL2RelayTest.java b/src/test/java/org/opencord/dhcpl2relay/DhcpL2RelayTest.java
new file mode 100755
index 0000000..e91fddd
--- /dev/null
+++ b/src/test/java/org/opencord/dhcpl2relay/DhcpL2RelayTest.java
@@ -0,0 +1,417 @@
+/*
+ * Copyright 2017-present Open Networking Foundation
+ *
+ * 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 org.opencord.dhcpl2relay;
+
+//import com.fasterxml.jackson.databind.util.Annotations;
+
+import org.easymock.EasyMock;
+
+import com.google.common.collect.Lists;
+import com.google.common.collect.ImmutableSet;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import org.onlab.osgi.ComponentContextAdapter;
+import org.onlab.packet.ChassisId;
+import org.onlab.packet.DHCP;
+import org.onlab.packet.DHCPOption;
+import org.onlab.packet.IpAddress;
+import org.onlab.packet.Ip4Address;
+import org.onlab.packet.IPv4;
+import org.onlab.packet.MacAddress;
+import org.onlab.packet.UDP;
+import org.onlab.packet.VlanId;
+
+import org.onosproject.mastership.MastershipServiceAdapter;
+import org.onosproject.net.Annotations;
+import org.onosproject.net.AnnotationKeys;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.DefaultAnnotations;
+import org.onosproject.net.PortNumber;
+import org.onosproject.cfg.ComponentConfigService;
+import org.onosproject.core.CoreServiceAdapter;
+import org.onosproject.net.config.Config;
+import org.onosproject.net.config.NetworkConfigRegistryAdapter;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.device.DeviceServiceAdapter;
+import org.onosproject.net.DefaultDevice;
+import org.onosproject.net.DefaultHost;
+import org.onosproject.net.Device;
+import org.onosproject.net.Element;
+import org.onosproject.net.host.HostServiceAdapter;
+import org.onosproject.net.Host;
+import org.onosproject.net.HostId;
+import org.onosproject.net.HostLocation;
+import org.onosproject.net.provider.ProviderId;
+import org.onosproject.net.Port;
+
+import org.opencord.dhcpl2relay.packet.DhcpEthernet;
+import org.opencord.dhcpl2relay.packet.DhcpOption82;
+import org.opencord.sadis.SubscriberAndDeviceInformation;
+import org.opencord.sadis.SubscriberAndDeviceInformationService;
+
+import java.nio.ByteBuffer;
+import java.util.List;
+import java.util.Set;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import static org.junit.Assert.assertEquals;
+
+public class DhcpL2RelayTest extends DhcpL2RelayTestBase {
+
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private DhcpL2Relay dhcpL2Relay;
+
+    private static final MacAddress CLIENT_MAC = MacAddress.valueOf("00:00:00:00:00:01");
+    private static final VlanId CLIENT_C_TAG = VlanId.vlanId((short) 999);
+    private static final VlanId CLIENT_S_TAG = VlanId.vlanId((short) 111);
+    private static final String CLIENT_NAS_PORT_ID = "PON 1/1";
+    private static final String CLIENT_CIRCUIT_ID = "CIR-PON 1/1";
+
+    private static final String OLT_DEV_ID = "of:00000000000000aa";
+    private static final MacAddress OLT_MAC_ADDRESS = MacAddress.valueOf("01:02:03:04:05:06");
+    private static final DeviceId DEVICE_ID_1 = DeviceId.deviceId(OLT_DEV_ID);
+
+    private static final ConnectPoint SERVER_CONNECT_POINT =
+            ConnectPoint.deviceConnectPoint("of:0000000000000001/5");
+
+    private static final String SCHEME_NAME = "dhcpl2relay";
+    private static final DefaultAnnotations DEVICE_ANNOTATIONS = DefaultAnnotations.builder()
+            .set(AnnotationKeys.PROTOCOL, SCHEME_NAME.toUpperCase()).build();
+
+    ComponentConfigService mockConfigService =
+            EasyMock.createMock(ComponentConfigService.class);
+
+    /**
+     * Sets up the services required by the dhcpl2relay app.
+     */
+    @Before
+    public void setUp() {
+        dhcpL2Relay = new DhcpL2Relay();
+        dhcpL2Relay.cfgService = new TestNetworkConfigRegistry();
+        dhcpL2Relay.coreService = new CoreServiceAdapter();
+        dhcpL2Relay.packetService = new MockPacketService();
+        dhcpL2Relay.componentConfigService = mockConfigService;
+        dhcpL2Relay.deviceService = new MockDeviceService();
+        dhcpL2Relay.subsService = new MockSubService();
+        dhcpL2Relay.hostService = new MockHostService();
+        dhcpL2Relay.mastershipService = new MockMastershipService();
+        dhcpL2Relay.activate(new ComponentContextAdapter());
+    }
+
+    /**
+     * Tears down the dhcpL2Relay application.
+     */
+    @After
+    public void tearDown() {
+        dhcpL2Relay.deactivate();
+    }
+
+    /**
+     * Tests the DHCP relay app by sending DHCP discovery Packet.
+     *
+     * @throws Exception when an unhandled error occurs
+     */
+    @Test
+    public void testDhcpDiscover()  throws Exception {
+        //  (1) Sending DHCP discover packet
+        System.out.println("Sending pakcet");
+        DhcpEthernet discoverPacket = constructDhcpDiscoverPacket(CLIENT_MAC);
+
+        sendPacket(discoverPacket, ConnectPoint.deviceConnectPoint(OLT_DEV_ID + "/" + 1));
+
+        DhcpEthernet discoverRelayed = (DhcpEthernet) getPacket();
+        compareClientPackets(discoverPacket, discoverRelayed);
+    }
+
+    /**
+     * Tests the DHCP relay app by sending DHCP Request Packet.
+     *
+     * @throws Exception when an unhandled error occurs
+     */
+    @Test
+    public void testDhcpRequest()  throws Exception {
+        //  (1) Sending DHCP discover packet
+        System.out.println("Sending pakcet");
+        DhcpEthernet requestPacket = constructDhcpRequestPacket(CLIENT_MAC);
+
+        sendPacket(requestPacket, ConnectPoint.deviceConnectPoint(OLT_DEV_ID + "/" + 1));
+
+        DhcpEthernet requestRelayed = (DhcpEthernet) getPacket();
+        compareClientPackets(requestPacket, requestRelayed);
+    }
+
+    /**
+     * Tests the DHCP relay app by sending DHCP Offer Packet.
+     *
+     * @throws Exception when an unhandled error occurs
+     */
+    @Test
+    public void testDhcpOffer() {
+        //  (1) Sending DHCP discover packet
+        System.out.println("Sending pakcet");
+        DhcpEthernet offerPacket = constructDhcpOfferPacket(MacAddress.valueOf("bb:bb:bb:bb:bb:bb"),
+                CLIENT_MAC, "1.1.1.1", "2.2.2.2");
+
+        sendPacket(offerPacket, ConnectPoint.deviceConnectPoint(OLT_DEV_ID + "/" + 1));
+
+        DhcpEthernet offerRelayed = (DhcpEthernet) getPacket();
+        compareServerPackets(offerPacket, offerRelayed);
+    }
+
+    /**
+     * Tests the DHCP relay app by sending DHCP Ack Packet.
+     *
+     * @throws Exception when an unhandled error occurs
+     */
+    @Test
+    public void testDhcpAck() {
+
+        DhcpEthernet ackPacket = constructDhcpAckPacket(MacAddress.valueOf("bb:bb:bb:bb:bb:bb"),
+                CLIENT_MAC, "1.1.1.1", "2.2.2.2");
+
+        sendPacket(ackPacket, ConnectPoint.deviceConnectPoint(OLT_DEV_ID + "/" + 1));
+
+        DhcpEthernet ackRelayed = (DhcpEthernet) getPacket();
+        compareServerPackets(ackPacket, ackRelayed);
+    }
+
+    public void compareClientPackets(DhcpEthernet sent, DhcpEthernet relayed) {
+        sent.setSourceMacAddress(OLT_MAC_ADDRESS);
+        sent.setQinQVid(CLIENT_S_TAG.toShort());
+        sent.setVlanID(CLIENT_C_TAG.toShort());
+
+        IPv4 ipv4Packet = (IPv4) sent.getPayload();
+        UDP udpPacket = (UDP) ipv4Packet.getPayload();
+        DHCP dhcpPacket = (DHCP) udpPacket.getPayload();
+
+        List<DHCPOption> options = Lists.newArrayList(dhcpPacket.getOptions());
+        DhcpOption82 option82 = new DhcpOption82();
+        option82.setAgentCircuitId(CLIENT_CIRCUIT_ID);
+
+        DHCPOption option = new DHCPOption()
+                .setCode(DHCP.DHCPOptionCode.OptionCode_CircuitID.getValue())
+                .setData(option82.toByteArray())
+                .setLength(option82.length());
+
+        options.add(options.size() - 1, option);
+        dhcpPacket.setOptions(options);
+
+        final ByteBuffer byteBuffer = ByteBuffer.wrap(sent.serialize());
+        DhcpEthernet expectedPacket = null;
+        try {
+            expectedPacket = DhcpEthernet.deserializer().deserialize(byteBuffer.array(),
+                    0, byteBuffer.array().length);
+        } catch (Exception e) {
+        }
+        assertEquals(expectedPacket, relayed);
+
+    }
+
+    public void compareServerPackets(DhcpEthernet sent, DhcpEthernet relayed) {
+        sent.setDestinationMacAddress(CLIENT_MAC);
+        sent.setQinQVid(CLIENT_S_TAG.toShort());
+        sent.setVlanID(CLIENT_C_TAG.toShort());
+
+        final ByteBuffer byteBuffer = ByteBuffer.wrap(sent.serialize());
+        DhcpEthernet expectedPacket = null;
+        try {
+            expectedPacket = DhcpEthernet.deserializer().deserialize(byteBuffer.array(),
+                    0, byteBuffer.array().length);
+        } catch (Exception e) {
+        }
+        assertEquals(expectedPacket, relayed);
+
+    }
+
+    private class MockDevice extends DefaultDevice {
+
+        public MockDevice(ProviderId providerId, DeviceId id, Type type,
+                          String manufacturer, String hwVersion, String swVersion,
+                          String serialNumber, ChassisId chassisId, Annotations... annotations) {
+            super(providerId, id, type, manufacturer, hwVersion, swVersion, serialNumber,
+                    chassisId, annotations);
+        }
+    }
+
+    private class MockDeviceService extends DeviceServiceAdapter {
+
+        private ProviderId providerId = new ProviderId("of", "foo");
+        private final Device device1 = new MockDevice(providerId, DEVICE_ID_1, Device.Type.SWITCH,
+                "foo.inc", "0", "0", OLT_DEV_ID, new ChassisId(),
+                DEVICE_ANNOTATIONS);
+
+        @Override
+        public Device getDevice(DeviceId devId) {
+            return device1;
+
+        }
+
+        @Override
+        public Port getPort(ConnectPoint cp) {
+            return new MockPort();
+        }
+
+        @Override
+        public boolean isAvailable(DeviceId d) {
+            return true;
+        }
+    }
+
+    private class  MockPort implements Port {
+
+        @Override
+        public boolean isEnabled() {
+            return true;
+        }
+        public long portSpeed() {
+            return 1000;
+        }
+        public Element element() {
+            return null;
+        }
+        public PortNumber number() {
+            return null;
+        }
+        public Annotations annotations() {
+            return new MockAnnotations();
+        }
+        public Type type() {
+            return Port.Type.FIBER;
+        }
+
+        private class MockAnnotations implements Annotations {
+
+            @Override
+            public String value(String val) {
+                return "PON 1/1";
+            }
+            public Set<String> keys() {
+                return null;
+            }
+        }
+    }
+
+    private class MockSubService implements SubscriberAndDeviceInformationService {
+        MockSubscriberAndDeviceInformation device =
+                new MockSubscriberAndDeviceInformation(OLT_DEV_ID, VlanId.NONE, VlanId.NONE, null, null,
+                        OLT_MAC_ADDRESS, Ip4Address.valueOf("10.10.10.10"));
+        MockSubscriberAndDeviceInformation sub =
+                new MockSubscriberAndDeviceInformation(CLIENT_NAS_PORT_ID, CLIENT_C_TAG,
+                        CLIENT_S_TAG, CLIENT_NAS_PORT_ID, CLIENT_CIRCUIT_ID, null, null);
+        @Override
+        public SubscriberAndDeviceInformation get(String id) {
+            if (id.equals(OLT_DEV_ID)) {
+                return device;
+            } else {
+                return  sub;
+            }
+        }
+
+        @Override
+        public void invalidateAll() {}
+        public void invalidateId(String id) {}
+        public SubscriberAndDeviceInformation getfromCache(String id) {
+            return null;
+        }
+    }
+
+    private class MockMastershipService extends MastershipServiceAdapter {
+        @Override
+        public boolean isLocalMaster(DeviceId d) {
+            return true;
+        }
+    }
+
+    private class MockSubscriberAndDeviceInformation extends SubscriberAndDeviceInformation {
+
+        MockSubscriberAndDeviceInformation(String id, VlanId ctag,
+                                           VlanId stag, String nasPortId,
+                                           String circuitId, MacAddress hardId,
+                                           Ip4Address ipAddress) {
+            this.setCTag(ctag);
+            this.setHardwareIdentifier(hardId);
+            this.setId(id);
+            this.setIPAddress(ipAddress);
+            this.setSTag(stag);
+            this.setNasPortId(nasPortId);
+            this.setCircuitId(circuitId);
+        }
+    }
+
+    private class MockHostService extends HostServiceAdapter {
+
+        @Override
+        public Set<Host> getHostsByMac(MacAddress mac) {
+
+            HostLocation loc = new HostLocation(DEVICE_ID_1, PortNumber.portNumber(22), 0);
+
+            IpAddress ip = IpAddress.valueOf("10.100.200.10");
+
+            Host h = new DefaultHost(ProviderId.NONE, HostId.hostId(mac, VlanId.NONE),
+                    mac, VlanId.NONE, loc, ImmutableSet.of(ip));
+
+            return ImmutableSet.of(h);
+        }
+    }
+
+
+    /**
+     * Mocks the AAAConfig class to force usage of an unroutable address for the
+     * RADIUS server.
+     */
+    static class MockDhcpL2RealyConfig extends DhcpL2RelayConfig {
+        @Override
+        public Set<ConnectPoint> getDhcpServerConnectPoint() {
+            return ImmutableSet.of(SERVER_CONNECT_POINT);
+        }
+    }
+
+    /**
+     * Mocks the network config registry.
+     */
+    @SuppressWarnings("unchecked")
+    private static final class TestNetworkConfigRegistry
+            extends NetworkConfigRegistryAdapter {
+        @Override
+        public <S, C extends Config<S>> C getConfig(S subject, Class<C> configClass) {
+            DhcpL2RelayConfig dhcpConfig = new MockDhcpL2RealyConfig();
+            return (C) dhcpConfig;
+        }
+    }
+}
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
diff --git a/src/test/java/org/opencord/dhcpl2relay/DhcpL2RelayTestBase.java b/src/test/java/org/opencord/dhcpl2relay/DhcpL2RelayTestBase.java
new file mode 100755
index 0000000..a80c0f8
--- /dev/null
+++ b/src/test/java/org/opencord/dhcpl2relay/DhcpL2RelayTestBase.java
@@ -0,0 +1,301 @@
+/*
+ * Copyright 2017-present Open Networking Foundation
+ *
+ * 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 org.opencord.dhcpl2relay;
+
+import org.onlab.packet.BasePacket;
+import org.onlab.packet.DHCP;
+import org.onlab.packet.DHCPOption;
+import org.onlab.packet.DHCPPacketType;
+import org.onlab.packet.Ethernet;
+import org.onlab.packet.IPv4;
+import org.onlab.packet.Ip4Address;
+import org.onlab.packet.MacAddress;
+import org.onlab.packet.UDP;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.packet.DefaultInboundPacket;
+import org.onosproject.net.packet.DefaultPacketContext;
+import org.onosproject.net.packet.InboundPacket;
+import org.onosproject.net.packet.OutboundPacket;
+import org.onosproject.net.packet.PacketContext;
+import org.onosproject.net.packet.PacketProcessor;
+import org.onosproject.net.packet.PacketServiceAdapter;
+
+import org.opencord.dhcpl2relay.packet.DhcpEthernet;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+
+import static org.junit.Assert.fail;
+
+
+/**
+ * Common methods for AAA app testing.
+ */
+public class DhcpL2RelayTestBase {
+    private final Logger log = LoggerFactory.getLogger(getClass());
+
+    private static final int TRANSACTION_ID = 1000;
+
+    private static final String EXPECTED_IP = "10.2.0.2";
+
+    List<BasePacket> savedPackets = new LinkedList<>();
+    PacketProcessor packetProcessor;
+
+
+    /**
+     * Saves the given packet onto the saved packets list.
+     *
+     * @param packet packet to save
+     */
+    void savePacket(BasePacket packet) {
+        savedPackets.add(packet);
+    }
+
+    BasePacket getPacket() {
+        return savedPackets.remove(0);
+    }
+
+    /**
+     * Keeps a reference to the PacketProcessor and saves the OutboundPackets.
+     */
+    class MockPacketService extends PacketServiceAdapter {
+
+        @Override
+        public void addProcessor(PacketProcessor processor, int priority) {
+            packetProcessor = processor;
+        }
+
+        @Override
+        public void emit(OutboundPacket packet) {
+            try {
+                DhcpEthernet eth = DhcpEthernet.deserializer().deserialize(packet.data().array(),
+                        0, packet.data().array().length);
+                savePacket(eth);
+            } catch (Exception e) {
+                fail(e.getMessage());
+            }
+        }
+    }
+
+    /**
+     * Mocks the DefaultPacketContext.
+     */
+    final class TestPacketContext extends DefaultPacketContext {
+
+        private TestPacketContext(long time, InboundPacket inPkt,
+                                  OutboundPacket outPkt, boolean block) {
+            super(time, inPkt, outPkt, block);
+        }
+
+        @Override
+        public void send() {
+            // We don't send anything out.
+        }
+    }
+
+    /**
+     * Sends an Ethernet packet to the process method of the Packet Processor.
+     *
+     * @param pkt Ethernet packet
+     */
+    void sendPacket(DhcpEthernet pkt, ConnectPoint cp) {
+        final ByteBuffer byteBuffer = ByteBuffer.wrap(pkt.serialize());
+        InboundPacket inPacket = new DefaultInboundPacket(cp, null, byteBuffer);
+
+        PacketContext context = new TestPacketContext(127L, inPacket, null, false);
+        packetProcessor.process(context);
+    }
+
+    /**
+     * Constructs an Ethernet packet with IP/UDP/DHCP payload.
+     *
+     * @return Ethernet packet
+     */
+    private DhcpEthernet construcEthernetPacket(MacAddress srcMac, MacAddress dstMac,
+                                                String dstIp, byte dhcpReqRsp,
+                                                MacAddress clientHwAddress,
+                                                Ip4Address dhcpClientIpAddress) {
+        // Ethernet Frame.
+        DhcpEthernet ethPkt = new DhcpEthernet();
+        ethPkt.setSourceMacAddress(srcMac);
+        ethPkt.setDestinationMacAddress(dstMac);
+        ethPkt.setEtherType(Ethernet.TYPE_IPV4);
+        ethPkt.setVlanID((short) 2);
+        ethPkt.setPriorityCode((byte) 6);
+
+        // IP Packet
+        IPv4 ipv4Reply = new IPv4();
+        ipv4Reply.setSourceAddress(0);
+        ipv4Reply.setDestinationAddress(dstIp);
+
+        ipv4Reply.setTtl((byte) 127);
+
+        // UDP Datagram.
+        UDP udpReply = new UDP();
+        udpReply.setSourcePort((byte) UDP.DHCP_CLIENT_PORT);
+        udpReply.setDestinationPort((byte) UDP.DHCP_SERVER_PORT);
+
+        // DHCP Payload.
+        DHCP dhcpReply = new DHCP();
+        dhcpReply.setOpCode(dhcpReqRsp);
+
+        dhcpReply.setYourIPAddress(dhcpClientIpAddress.toInt());
+        dhcpReply.setServerIPAddress(0);
+
+        final byte[] serverNameBytes = new byte[64];
+        String result = new String(serverNameBytes, StandardCharsets.US_ASCII).trim();
+        dhcpReply.setServerName(result);
+
+        final byte[] bootFileBytes = new byte[128];
+        String result1 = new String(bootFileBytes, StandardCharsets.US_ASCII).trim();
+        dhcpReply.setBootFileName(result1);
+
+        dhcpReply.setTransactionId(TRANSACTION_ID);
+        dhcpReply.setClientHardwareAddress(clientHwAddress.toBytes());
+        dhcpReply.setHardwareType(DHCP.HWTYPE_ETHERNET);
+        dhcpReply.setHardwareAddressLength((byte) 6);
+
+        udpReply.setPayload(dhcpReply);
+        ipv4Reply.setPayload(udpReply);
+        ethPkt.setPayload(ipv4Reply);
+
+        return ethPkt;
+    }
+
+    /**
+     * Constructs DHCP Discover Packet.
+     *
+     * @return Ethernet packet
+     */
+    DhcpEthernet constructDhcpDiscoverPacket(MacAddress clientMac) {
+
+        DhcpEthernet pkt = construcEthernetPacket(clientMac, MacAddress.BROADCAST,
+                "255.255.255.255", DHCP.OPCODE_REQUEST, MacAddress.NONE,
+                Ip4Address.valueOf("0.0.0.0"));
+
+        IPv4 ipv4Packet = (IPv4) pkt.getPayload();
+        UDP udpPacket = (UDP) ipv4Packet.getPayload();
+        DHCP dhcpPacket = (DHCP) udpPacket.getPayload();
+
+        dhcpPacket.setOptions(constructDhcpOptions(DHCPPacketType.DHCPDISCOVER));
+
+        return pkt;
+    }
+
+    /**
+     * Constructs DHCP Request Packet.
+     *
+     * @return Ethernet packet
+     */
+    DhcpEthernet constructDhcpRequestPacket(MacAddress clientMac) {
+
+        DhcpEthernet pkt = construcEthernetPacket(clientMac, MacAddress.BROADCAST,
+                "255.255.255.255", DHCP.OPCODE_REQUEST, MacAddress.NONE,
+                Ip4Address.valueOf("0.0.0.0"));
+
+        IPv4 ipv4Packet = (IPv4) pkt.getPayload();
+        UDP udpPacket = (UDP) ipv4Packet.getPayload();
+        DHCP dhcpPacket = (DHCP) udpPacket.getPayload();
+
+        dhcpPacket.setOptions(constructDhcpOptions(DHCPPacketType.DHCPREQUEST));
+
+        return pkt;
+    }
+
+    /**
+     * Constructs DHCP Offer Packet.
+     *
+     * @return Ethernet packet
+     */
+    DhcpEthernet constructDhcpOfferPacket(MacAddress servMac, MacAddress clientMac,
+                                           String ipAddress, String dhcpClientIpAddress) {
+
+        DhcpEthernet pkt = construcEthernetPacket(servMac, clientMac, ipAddress, DHCP.OPCODE_REPLY,
+                clientMac, Ip4Address.valueOf(dhcpClientIpAddress));
+
+        IPv4 ipv4Packet = (IPv4) pkt.getPayload();
+        UDP udpPacket = (UDP) ipv4Packet.getPayload();
+        DHCP dhcpPacket = (DHCP) udpPacket.getPayload();
+
+        dhcpPacket.setOptions(constructDhcpOptions(DHCPPacketType.DHCPOFFER));
+
+        return pkt;
+    }
+
+    /**
+     * Constructs DHCP Ack Packet.
+     *
+     * @return Ethernet packet
+     */
+    DhcpEthernet constructDhcpAckPacket(MacAddress servMac, MacAddress clientMac,
+                                           String ipAddress, String dhcpClientIpAddress) {
+
+        DhcpEthernet pkt = construcEthernetPacket(servMac, clientMac, ipAddress, DHCP.OPCODE_REPLY,
+                clientMac, Ip4Address.valueOf(dhcpClientIpAddress));
+
+        IPv4 ipv4Packet = (IPv4) pkt.getPayload();
+        UDP udpPacket = (UDP) ipv4Packet.getPayload();
+        DHCP dhcpPacket = (DHCP) udpPacket.getPayload();
+
+        dhcpPacket.setOptions(constructDhcpOptions(DHCPPacketType.DHCPACK));
+
+        return pkt;
+    }
+
+    /**
+     * Constructs DHCP Discover Options.
+     *
+     * @return Ethernet packet
+     */
+    private List<DHCPOption> constructDhcpOptions(DHCPPacketType packetType) {
+
+        // DHCP Options.
+        DHCPOption option = new DHCPOption();
+        List<DHCPOption> optionList = new ArrayList<>();
+
+
+        // DHCP Message Type.
+        option.setCode(DHCP.DHCPOptionCode.OptionCode_MessageType.getValue());
+        option.setLength((byte) 1);
+        byte[] optionData = {(byte) packetType.getValue()};
+        option.setData(optionData);
+        optionList.add(option);
+
+        // DHCP Requested IP.
+        option = new DHCPOption();
+        option.setCode(DHCP.DHCPOptionCode.OptionCode_RequestedIP.getValue());
+        option.setLength((byte) 4);
+        optionData = Ip4Address.valueOf(EXPECTED_IP).toOctets();
+        option.setData(optionData);
+        optionList.add(option);
+
+        // End Option.
+        option = new DHCPOption();
+        option.setCode(DHCP.DHCPOptionCode.OptionCode_END.getValue());
+        option.setLength((byte) 1);
+        optionList.add(option);
+
+        return optionList;
+    }
+}