diff --git a/apps/sdnip/src/test/java/org/onlab/onos/sdnip/RouterTest.java b/apps/sdnip/src/test/java/org/onlab/onos/sdnip/RouterTest.java
index 6d77a2c..13547ae 100644
--- a/apps/sdnip/src/test/java/org/onlab/onos/sdnip/RouterTest.java
+++ b/apps/sdnip/src/test/java/org/onlab/onos/sdnip/RouterTest.java
@@ -69,6 +69,8 @@
 /**
  * This class tests adding a route, updating a route, deleting a route,
  * and adding a route whose next hop is the local BGP speaker.
+ * <p/>
+ * ARP module answers the MAC address synchronously.
  */
 public class RouterTest {
 
diff --git a/apps/sdnip/src/test/java/org/onlab/onos/sdnip/RouterTestWithAsyncArp.java b/apps/sdnip/src/test/java/org/onlab/onos/sdnip/RouterTestWithAsyncArp.java
new file mode 100644
index 0000000..c2e2019
--- /dev/null
+++ b/apps/sdnip/src/test/java/org/onlab/onos/sdnip/RouterTestWithAsyncArp.java
@@ -0,0 +1,394 @@
+package org.onlab.onos.sdnip;
+
+import static org.easymock.EasyMock.anyObject;
+import static org.easymock.EasyMock.createMock;
+import static org.easymock.EasyMock.expect;
+import static org.easymock.EasyMock.replay;
+import static org.easymock.EasyMock.reset;
+import static org.easymock.EasyMock.verify;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.onlab.junit.TestUtils;
+import org.onlab.junit.TestUtils.TestUtilsException;
+import org.onlab.onos.ApplicationId;
+import org.onlab.onos.net.ConnectPoint;
+import org.onlab.onos.net.DefaultHost;
+import org.onlab.onos.net.DeviceId;
+import org.onlab.onos.net.Host;
+import org.onlab.onos.net.HostId;
+import org.onlab.onos.net.HostLocation;
+import org.onlab.onos.net.PortNumber;
+import org.onlab.onos.net.flow.DefaultTrafficSelector;
+import org.onlab.onos.net.flow.DefaultTrafficTreatment;
+import org.onlab.onos.net.flow.TrafficSelector;
+import org.onlab.onos.net.flow.TrafficTreatment;
+import org.onlab.onos.net.host.HostEvent;
+import org.onlab.onos.net.host.HostService;
+import org.onlab.onos.net.host.InterfaceIpAddress;
+import org.onlab.onos.net.intent.IntentService;
+import org.onlab.onos.net.intent.MultiPointToSinglePointIntent;
+import org.onlab.onos.net.provider.ProviderId;
+import org.onlab.onos.sdnip.Router.InternalHostListener;
+import org.onlab.onos.sdnip.config.BgpPeer;
+import org.onlab.onos.sdnip.config.Interface;
+import org.onlab.onos.sdnip.config.SdnIpConfigService;
+import org.onlab.packet.Ethernet;
+import org.onlab.packet.IpAddress;
+import org.onlab.packet.IpPrefix;
+import org.onlab.packet.MacAddress;
+import org.onlab.packet.VlanId;
+
+import com.google.common.collect.Sets;
+import com.googlecode.concurrenttrees.radix.node.concrete.DefaultByteArrayNodeFactory;
+import com.googlecode.concurrenttrees.radixinverted.ConcurrentInvertedRadixTree;
+import com.googlecode.concurrenttrees.radixinverted.InvertedRadixTree;
+
+/**
+ * This class tests adding a route, updating a route, deleting a route, and
+ * the ARP module answers the MAC address asynchronously.
+ */
+public class RouterTestWithAsyncArp {
+
+    private SdnIpConfigService sdnIpConfigService;
+    private InterfaceService interfaceService;
+    private IntentService intentService;
+    private HostService hostService;
+
+    private static final ConnectPoint SW1_ETH1 = new ConnectPoint(
+            DeviceId.deviceId("of:0000000000000001"),
+            PortNumber.portNumber(1));
+
+    private static final ConnectPoint SW2_ETH1 = new ConnectPoint(
+            DeviceId.deviceId("of:0000000000000002"),
+            PortNumber.portNumber(1));
+
+    private static final ConnectPoint SW3_ETH1 = new ConnectPoint(
+            DeviceId.deviceId("of:0000000000000003"),
+            PortNumber.portNumber(1));
+
+    private Router router;
+    private InternalHostListener internalHostListener;
+
+    private static final ApplicationId APPID = new ApplicationId() {
+        @Override
+        public short id() {
+            return 1;
+        }
+
+        @Override
+        public String name() {
+            return "SDNIP";
+        }
+    };
+
+    @Before
+    public void setUp() throws Exception {
+        setUpSdnIpConfigService();
+        setUpInterfaceService();
+        hostService = createMock(HostService.class);
+        intentService = createMock(IntentService.class);
+
+        router = new Router(APPID, intentService,
+                hostService, sdnIpConfigService, interfaceService);
+        internalHostListener = router.new InternalHostListener();
+    }
+
+    /**
+     * Sets up SdnIpConfigService.
+     */
+    private void setUpSdnIpConfigService() {
+
+        sdnIpConfigService = createMock(SdnIpConfigService.class);
+
+        Map<IpAddress, BgpPeer> peers = new HashMap<>();
+
+        String peerSw1Eth1 = "192.168.10.1";
+        peers.put(IpAddress.valueOf(peerSw1Eth1),
+                new BgpPeer("00:00:00:00:00:00:00:01", 1, peerSw1Eth1));
+
+        // Two BGP peers are connected to switch 2 port 1.
+        String peer1Sw2Eth1 = "192.168.20.1";
+        peers.put(IpAddress.valueOf(peer1Sw2Eth1),
+                new BgpPeer("00:00:00:00:00:00:00:02", 1, peer1Sw2Eth1));
+
+        String peer2Sw2Eth1 = "192.168.20.2";
+        peers.put(IpAddress.valueOf(peer2Sw2Eth1),
+                new BgpPeer("00:00:00:00:00:00:00:02", 1, peer2Sw2Eth1));
+
+        expect(sdnIpConfigService.getBgpPeers()).andReturn(peers).anyTimes();
+        replay(sdnIpConfigService);
+    }
+
+    /**
+     * Sets up InterfaceService.
+     */
+    private void setUpInterfaceService() {
+
+        interfaceService = createMock(InterfaceService.class);
+
+        Set<Interface> interfaces = Sets.newHashSet();
+
+        Set<InterfaceIpAddress> interfaceIpAddresses1 = Sets.newHashSet();
+        interfaceIpAddresses1.add(new InterfaceIpAddress(
+                IpAddress.valueOf("192.168.10.101"),
+                IpPrefix.valueOf("192.168.10.0/24")));
+        Interface sw1Eth1 = new Interface(SW1_ETH1,
+                interfaceIpAddresses1, MacAddress.valueOf("00:00:00:00:00:01"));
+        interfaces.add(sw1Eth1);
+
+        Set<InterfaceIpAddress> interfaceIpAddresses2 = Sets.newHashSet();
+        interfaceIpAddresses2.add(new InterfaceIpAddress(
+                IpAddress.valueOf("192.168.20.101"),
+                IpPrefix.valueOf("192.168.20.0/24")));
+        Interface sw2Eth1 = new Interface(SW2_ETH1,
+                interfaceIpAddresses2, MacAddress.valueOf("00:00:00:00:00:02"));
+        interfaces.add(sw2Eth1);
+
+        Set<InterfaceIpAddress> interfaceIpAddresses3 = Sets.newHashSet();
+        interfaceIpAddresses3.add(new InterfaceIpAddress(
+                IpAddress.valueOf("192.168.30.101"),
+                IpPrefix.valueOf("192.168.30.0/24")));
+        Interface sw3Eth1 = new Interface(SW3_ETH1,
+                interfaceIpAddresses3, MacAddress.valueOf("00:00:00:00:00:03"));
+        interfaces.add(sw3Eth1);
+
+        expect(interfaceService.getInterface(SW1_ETH1)).andReturn(sw1Eth1).anyTimes();
+        expect(interfaceService.getInterface(SW2_ETH1)).andReturn(sw2Eth1).anyTimes();
+        expect(interfaceService.getInterface(SW3_ETH1)).andReturn(sw3Eth1).anyTimes();
+        expect(interfaceService.getInterfaces()).andReturn(interfaces).anyTimes();
+        replay(interfaceService);
+    }
+
+    /**
+     * This method tests adding a route entry.
+     */
+    @Test
+    public void testProcessRouteAdd() throws TestUtilsException {
+
+        // Construct a route entry
+        RouteEntry routeEntry = new RouteEntry(
+                IpPrefix.valueOf("1.1.1.0/24"),
+                IpAddress.valueOf("192.168.10.1"));
+
+        // Construct a route intent
+        MultiPointToSinglePointIntent intent = staticIntentBuilder();
+
+        // Set up test expectation
+        reset(hostService);
+        expect(hostService.getHostsByIp(anyObject(IpPrefix.class))).andReturn(
+                new HashSet<Host>()).anyTimes();
+        hostService.startMonitoringIp(IpAddress.valueOf("192.168.10.1"));
+        replay(hostService);
+
+        reset(intentService);
+        intentService.submit(intent);
+        replay(intentService);
+
+        // Call the processRouteAdd() method in Router class
+        router.leaderChanged(true);
+        TestUtils.setField(router, "isActivatedLeader", true);
+        router.processRouteAdd(routeEntry);
+
+        Host host = new DefaultHost(ProviderId.NONE, HostId.NONE,
+                MacAddress.valueOf("00:00:00:00:00:01"), VlanId.NONE,
+                new HostLocation(
+                        SW1_ETH1.deviceId(),
+                        SW1_ETH1.port(), 1),
+                        Sets.newHashSet(IpPrefix.valueOf("192.168.10.1/32")));
+        internalHostListener.event(
+                new HostEvent(HostEvent.Type.HOST_ADDED, host));
+
+        // Verify
+        assertEquals(router.getRoutes().size(), 1);
+        assertTrue(router.getRoutes().contains(routeEntry));
+        assertEquals(router.getPushedRouteIntents().size(), 1);
+        assertEquals(router.getPushedRouteIntents().iterator().next(),
+                intent);
+        verify(intentService);
+        verify(hostService);
+
+    }
+
+    /**
+     * This method tests updating a route entry.
+     *
+     * @throws TestUtilsException
+     */
+    @Test
+    public void testRouteUpdate() throws TestUtilsException {
+
+        // Construct the existing route entry
+        RouteEntry routeEntry = new RouteEntry(
+                IpPrefix.valueOf("1.1.1.0/24"),
+                IpAddress.valueOf("192.168.10.1"));
+
+        // Construct the existing MultiPointToSinglePointIntent intent
+        MultiPointToSinglePointIntent intent = staticIntentBuilder();
+
+        // Set up the bgpRoutes field of Router class with existing route, and
+        // pushedRouteIntents field with the corresponding existing intent
+        setBgpRoutesField(routeEntry);
+        setPushedRouteIntentsField(routeEntry, intent);
+
+        // Start to construct a new route entry and new intent
+        RouteEntry routeEntryUpdate = new RouteEntry(
+                IpPrefix.valueOf("1.1.1.0/24"),
+                IpAddress.valueOf("192.168.20.1"));
+
+        // Construct a new MultiPointToSinglePointIntent intent
+        TrafficSelector.Builder selectorBuilderNew =
+                DefaultTrafficSelector.builder();
+        selectorBuilderNew.matchEthType(Ethernet.TYPE_IPV4).matchIPDst(
+                routeEntryUpdate.prefix());
+
+        TrafficTreatment.Builder treatmentBuilderNew =
+                DefaultTrafficTreatment.builder();
+        treatmentBuilderNew.setEthDst(MacAddress.valueOf("00:00:00:00:00:02"));
+
+        Set<ConnectPoint> ingressPointsNew = new HashSet<ConnectPoint>();
+        ingressPointsNew.add(SW1_ETH1);
+        ingressPointsNew.add(SW3_ETH1);
+
+        MultiPointToSinglePointIntent intentNew =
+                new MultiPointToSinglePointIntent(APPID,
+                        selectorBuilderNew.build(),
+                        treatmentBuilderNew.build(),
+                        ingressPointsNew, SW2_ETH1);
+
+        // Set up test expectation
+        reset(hostService);
+        expect(hostService.getHostsByIp(anyObject(IpPrefix.class))).andReturn(
+                new HashSet<Host>()).anyTimes();
+        hostService.startMonitoringIp(IpAddress.valueOf("192.168.20.1"));
+        replay(hostService);
+
+        reset(intentService);
+        intentService.withdraw(intent);
+        intentService.submit(intentNew);
+        replay(intentService);
+
+        // Call the processRouteAdd() method in Router class
+        router.leaderChanged(true);
+        TestUtils.setField(router, "isActivatedLeader", true);
+        router.processRouteAdd(routeEntryUpdate);
+
+        Host host = new DefaultHost(ProviderId.NONE, HostId.NONE,
+                MacAddress.valueOf("00:00:00:00:00:02"), VlanId.NONE,
+                new HostLocation(
+                        SW2_ETH1.deviceId(),
+                        SW2_ETH1.port(), 1),
+                        Sets.newHashSet(IpPrefix.valueOf("192.168.20.1/32")));
+        internalHostListener.event(
+                new HostEvent(HostEvent.Type.HOST_ADDED, host));
+
+        // Verify
+        assertEquals(router.getRoutes().size(), 1);
+        assertTrue(router.getRoutes().contains(routeEntryUpdate));
+        assertEquals(router.getPushedRouteIntents().size(), 1);
+        assertEquals(router.getPushedRouteIntents().iterator().next(),
+                intentNew);
+        verify(intentService);
+        verify(hostService);
+    }
+
+    /**
+     * This method tests deleting a route entry.
+     */
+    @Test
+    public void testProcessRouteDelete() throws TestUtilsException {
+
+        // Construct the existing route entry
+        RouteEntry routeEntry = new RouteEntry(
+                IpPrefix.valueOf("1.1.1.0/24"),
+                IpAddress.valueOf("192.168.10.1"));
+
+        // Construct the existing MultiPointToSinglePointIntent intent
+        MultiPointToSinglePointIntent intent = staticIntentBuilder();
+
+        // Set up the bgpRoutes field of Router class with existing route, and
+        // pushedRouteIntents field with the corresponding existing intent
+        setBgpRoutesField(routeEntry);
+        setPushedRouteIntentsField(routeEntry, intent);
+
+        // Set up expectation
+        reset(intentService);
+        intentService.withdraw(intent);
+        replay(intentService);
+
+        // Call route deleting method in Router class
+        router.leaderChanged(true);
+        TestUtils.setField(router, "isActivatedLeader", true);
+        router.processRouteDelete(routeEntry);
+
+        // Verify
+        assertEquals(router.getRoutes().size(), 0);
+        assertEquals(router.getPushedRouteIntents().size(), 0);
+        verify(intentService);
+    }
+
+    /**
+     * Constructs a static MultiPointToSinglePointIntent.
+     */
+    private MultiPointToSinglePointIntent staticIntentBuilder() {
+
+        TrafficSelector.Builder selectorBuilder =
+                DefaultTrafficSelector.builder();
+        selectorBuilder.matchEthType(Ethernet.TYPE_IPV4).matchIPDst(
+                IpPrefix.valueOf("1.1.1.0/24"));
+
+        TrafficTreatment.Builder treatmentBuilder =
+                DefaultTrafficTreatment.builder();
+        treatmentBuilder.setEthDst(MacAddress.valueOf("00:00:00:00:00:01"));
+
+        Set<ConnectPoint> ingressPoints = new HashSet<ConnectPoint>();
+        ingressPoints.add(SW2_ETH1);
+        ingressPoints.add(SW3_ETH1);
+
+        MultiPointToSinglePointIntent intent =
+                new MultiPointToSinglePointIntent(APPID,
+                        selectorBuilder.build(), treatmentBuilder.build(),
+                        ingressPoints, SW1_ETH1);
+
+        return intent;
+    }
+
+    /**
+     * Sets bgpRoutesField in Router class.
+     *
+     * @throws TestUtilsException
+     */
+    private void setBgpRoutesField(RouteEntry routeEntry)
+            throws TestUtilsException {
+
+        InvertedRadixTree<RouteEntry> bgpRoutes =
+                new ConcurrentInvertedRadixTree<>(
+                new DefaultByteArrayNodeFactory());
+        bgpRoutes.put(RouteEntry.createBinaryString(routeEntry.prefix()),
+                routeEntry);
+        TestUtils.setField(router, "bgpRoutes", bgpRoutes);
+    }
+
+    /**
+     * Sets pushedRouteIntentsField in Router class.
+     *
+     * @throws TestUtilsException
+     */
+    private void setPushedRouteIntentsField(RouteEntry routeEntry,
+            MultiPointToSinglePointIntent intent)
+            throws TestUtilsException {
+
+        ConcurrentHashMap<IpPrefix, MultiPointToSinglePointIntent>
+        pushedRouteIntents =  new ConcurrentHashMap<>();
+        pushedRouteIntents.put(routeEntry.prefix(), intent);
+        TestUtils.setField(router, "pushedRouteIntents", pushedRouteIntents);
+    }
+}
\ No newline at end of file