diff --git a/apps/route-service/app/src/main/java/org/onosproject/routeservice/impl/DefaultResolvedRouteStore.java b/apps/route-service/app/src/main/java/org/onosproject/routeservice/impl/DefaultResolvedRouteStore.java
index 4981932..725a7a9 100644
--- a/apps/route-service/app/src/main/java/org/onosproject/routeservice/impl/DefaultResolvedRouteStore.java
+++ b/apps/route-service/app/src/main/java/org/onosproject/routeservice/impl/DefaultResolvedRouteStore.java
@@ -143,7 +143,7 @@
                                 immutableAlternatives);
                     } else {
                         return new RouteEvent(RouteEvent.Type.ROUTE_UPDATED, route,
-                                oldRoute, immutableAlternatives);
+                                oldRoute, immutableAlternatives, oldRoutes);
                     }
                 }
 
@@ -185,11 +185,11 @@
                 String key = createBinaryString(prefix);
 
                 ResolvedRoute route = routeTable.getValueForExactKey(key);
-                alternativeRoutes.remove(prefix);
+                Set<ResolvedRoute> alternatives = alternativeRoutes.remove(prefix);
 
                 if (route != null) {
                     routeTable.remove(key);
-                    return new RouteEvent(RouteEvent.Type.ROUTE_REMOVED, route);
+                    return new RouteEvent(RouteEvent.Type.ROUTE_REMOVED, route, alternatives);
                 }
                 return null;
             }
diff --git a/apps/route-service/app/src/test/java/org/onosproject/routeservice/impl/RouteManagerTest.java b/apps/route-service/app/src/test/java/org/onosproject/routeservice/impl/RouteManagerTest.java
index 8febe68..3ba34da 100644
--- a/apps/route-service/app/src/test/java/org/onosproject/routeservice/impl/RouteManagerTest.java
+++ b/apps/route-service/app/src/test/java/org/onosproject/routeservice/impl/RouteManagerTest.java
@@ -16,6 +16,7 @@
 
 package org.onosproject.routeservice.impl;
 
+import java.util.Collection;
 import java.util.Collections;
 
 import org.junit.Before;
@@ -212,7 +213,8 @@
     private void verifyRouteAdd(Route route, ResolvedRoute resolvedRoute) {
         reset(routeListener);
 
-        routeListener.event(event(RouteEvent.Type.ROUTE_ADDED, resolvedRoute));
+        routeListener.event(event(RouteEvent.Type.ROUTE_ADDED, resolvedRoute, null,
+                Sets.newHashSet(resolvedRoute), null));
 
         replay(routeListener);
 
@@ -267,7 +269,8 @@
         addRoute(original);
 
         routeListener.event(event(RouteEvent.Type.ROUTE_UPDATED,
-                updatedResolvedRoute, resolvedRoute));
+                updatedResolvedRoute, resolvedRoute,
+                Sets.newHashSet(updatedResolvedRoute), Sets.newHashSet(resolvedRoute)));
         expectLastCall().once();
 
         replay(routeListener);
@@ -304,7 +307,7 @@
         addRoute(route);
 
         RouteEvent withdrawRouteEvent = new RouteEvent(RouteEvent.Type.ROUTE_REMOVED,
-                removedResolvedRoute);
+                removedResolvedRoute, Sets.newHashSet(removedResolvedRoute));
 
         reset(routeListener);
         routeListener.event(withdrawRouteEvent);
@@ -342,8 +345,9 @@
 
         // Now when we send the event, we expect the FIB update to be sent
         reset(routeListener);
-        routeListener.event(event(RouteEvent.Type.ROUTE_ADDED,
-                new ResolvedRoute(route, MAC1, CP1)));
+        ResolvedRoute resolvedRoute = new ResolvedRoute(route, MAC1, CP1);
+        routeListener.event(event(RouteEvent.Type.ROUTE_ADDED, resolvedRoute, null,
+                Sets.newHashSet(resolvedRoute), null));
         replay(routeListener);
 
         Host host = createHost(MAC1, V4_NEXT_HOP1);
@@ -362,12 +366,10 @@
         verify(routeListener);
     }
 
-    private static RouteEvent event(RouteEvent.Type type, ResolvedRoute subject) {
-        return event(type, subject, null);
-    }
-
-    private static RouteEvent event(RouteEvent.Type type, ResolvedRoute subject, ResolvedRoute prevSubject) {
-        return new RouteEvent(type, subject, prevSubject, Collections.singleton(subject));
+    private static RouteEvent event(RouteEvent.Type type, ResolvedRoute subject, ResolvedRoute prevSubject,
+                                    Collection<ResolvedRoute> alternatives,
+                                    Collection<ResolvedRoute> prevAlternatives) {
+        return new RouteEvent(type, subject, prevSubject, alternatives, prevAlternatives);
     }
 
     /**
diff --git a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/DefaultRoutingHandler.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/DefaultRoutingHandler.java
index 50b0cd2..0d263e7 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/DefaultRoutingHandler.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/DefaultRoutingHandler.java
@@ -27,11 +27,14 @@
 import org.onlab.packet.Ip4Address;
 import org.onlab.packet.Ip6Address;
 import org.onlab.packet.IpPrefix;
+import org.onlab.packet.MacAddress;
+import org.onlab.packet.VlanId;
 import org.onosproject.cluster.NodeId;
 import org.onosproject.net.ConnectPoint;
 import org.onosproject.net.Device;
 import org.onosproject.net.DeviceId;
 import org.onosproject.net.Link;
+import org.onosproject.net.PortNumber;
 import org.onosproject.segmentrouting.config.DeviceConfigNotFoundException;
 import org.onosproject.segmentrouting.config.DeviceConfiguration;
 import org.onosproject.segmentrouting.grouphandler.DefaultGroupHandler;
@@ -238,7 +241,8 @@
      *
      * @param cpts connect point(s) of the subnets being added
      * @param subnets subnets being added
-     */ //XXX refactor
+     */
+    // XXX refactor
     protected void populateSubnet(Set<ConnectPoint> cpts, Set<IpPrefix> subnets) {
         lastRoutingChange = DateTime.now();
         statusLock.lock();
@@ -250,7 +254,8 @@
             }
             populationStatus = Status.STARTED;
             rulePopulator.resetCounter();
-            log.info("Starting to populate routing rules for added routes");
+            log.info("Starting to populate routing rules for added routes, subnets={}, cpts={}",
+                    subnets, cpts);
             // Take snapshots of the topology
             updatedEcmpSpgMap = new HashMap<>();
             Set<EdgePair> edgePairs = new HashSet<>();
@@ -972,6 +977,40 @@
     }
 
     /**
+     * Populates IP rules for a route that has direct connection to the switch
+     * if the current instance is the master of the switch.
+     *
+     * @param deviceId device ID of the device that next hop attaches to
+     * @param prefix IP prefix of the route
+     * @param hostMac MAC address of the next hop
+     * @param hostVlanId Vlan ID of the nexthop
+     * @param outPort port where the next hop attaches to
+     */
+    void populateRoute(DeviceId deviceId, IpPrefix prefix,
+                       MacAddress hostMac, VlanId hostVlanId, PortNumber outPort) {
+        if (srManager.mastershipService.isLocalMaster(deviceId)) {
+            srManager.routingRulePopulator.populateRoute(deviceId, prefix, hostMac, hostVlanId, outPort);
+        }
+    }
+
+    /**
+     * Removes IP rules for a route when the next hop is gone.
+     * if the current instance is the master of the switch.
+     *
+     * @param deviceId device ID of the device that next hop attaches to
+     * @param prefix IP prefix of the route
+     * @param hostMac MAC address of the next hop
+     * @param hostVlanId Vlan ID of the nexthop
+     * @param outPort port that next hop attaches to
+     */
+    void revokeRoute(DeviceId deviceId, IpPrefix prefix,
+                     MacAddress hostMac, VlanId hostVlanId, PortNumber outPort) {
+        if (srManager.mastershipService.isLocalMaster(deviceId)) {
+            srManager.routingRulePopulator.revokeRoute(deviceId, prefix, hostMac, hostVlanId, outPort);
+        }
+    }
+
+    /**
      * Remove ECMP graph entry for the given device. Typically called when
      * device is no longer available.
      *
diff --git a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/HostHandler.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/HostHandler.java
index 5029b30..7a205ee 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/HostHandler.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/HostHandler.java
@@ -50,7 +50,6 @@
  * Handles host-related events.
  */
 public class HostHandler {
-    private static final String NOT_MASTER = "Current instance is not the master of {}. Ignore.";
 
     private static final Logger log = LoggerFactory.getLogger(HostHandler.class);
     protected final SegmentRoutingManager srManager;
@@ -87,8 +86,7 @@
     void processHostAddedAtLocation(Host host, HostLocation location) {
         checkArgument(host.locations().contains(location), "{} is not a location of {}", location, host);
 
-        if (!isMasterOf(location)) {
-            log.debug(NOT_MASTER, location);
+        if (!srManager.isMasterOf(location)) {
             return;
         }
 
@@ -115,16 +113,19 @@
         Set<IpAddress> ips = host.ipAddresses();
         log.info("Host {}/{} is removed from {}", hostMac, hostVlanId, locations);
 
-        locations.stream().filter(this::isMasterOf).forEach(location -> {
-            processBridgingRule(location.deviceId(), location.port(), hostMac, hostVlanId, true);
-            ips.forEach(ip ->
-                processRoutingRule(location.deviceId(), location.port(), hostMac, hostVlanId, ip, true)
-            );
+        locations.forEach(location -> {
+            if (srManager.isMasterOf(location)) {
+                processBridgingRule(location.deviceId(), location.port(), hostMac, hostVlanId, true);
+                ips.forEach(ip ->
+                        processRoutingRule(location.deviceId(), location.port(), hostMac, hostVlanId, ip, true)
+                );
+            }
 
             // Also remove redirection flows on the pair device if exists.
             Optional<DeviceId> pairDeviceId = srManager.getPairDeviceId(location.deviceId());
             Optional<PortNumber> pairLocalPort = srManager.getPairLocalPorts(location.deviceId());
-            if (pairDeviceId.isPresent() && pairLocalPort.isPresent()) {
+            if (pairDeviceId.isPresent() && pairLocalPort.isPresent() &&
+                    srManager.mastershipService.isLocalMaster(pairDeviceId.get())) {
                 // NOTE: Since the pairLocalPort is trunk port, use assigned vlan of original port
                 //       when the host is untagged
                 VlanId vlanId = Optional.ofNullable(srManager.getInternalVlanId(location)).orElse(hostVlanId);
@@ -150,7 +151,7 @@
                 .collect(Collectors.toSet());
 
         // For each old location
-        Sets.difference(prevLocations, newLocations).stream().filter(this::isMasterOf)
+        Sets.difference(prevLocations, newLocations).stream().filter(srManager::isMasterOf)
                 .forEach(prevLocation -> {
             // Remove routing rules for old IPs
             Sets.difference(prevIps, newIps).forEach(ip ->
@@ -211,7 +212,7 @@
         });
 
         // For each new location, add all new IPs.
-        Sets.difference(newLocations, prevLocations).stream().filter(this::isMasterOf)
+        Sets.difference(newLocations, prevLocations).stream().filter(srManager::isMasterOf)
                 .forEach(newLocation -> {
             processBridgingRule(newLocation.deviceId(), newLocation.port(), hostMac, hostVlanId, false);
             newIps.forEach(ip ->
@@ -221,7 +222,7 @@
         });
 
         // For each unchanged location, add new IPs and remove old IPs.
-        Sets.intersection(newLocations, prevLocations).stream().filter(this::isMasterOf)
+        Sets.intersection(newLocations, prevLocations).stream().filter(srManager::isMasterOf)
                 .forEach(unchangedLocation -> {
             Sets.difference(prevIps, newIps).forEach(ip ->
                     processRoutingRule(unchangedLocation.deviceId(), unchangedLocation.port(), hostMac,
@@ -243,7 +244,7 @@
         Set<IpAddress> newIps = event.subject().ipAddresses();
         log.info("Host {}/{} is updated", mac, vlanId);
 
-        locations.stream().filter(this::isMasterOf).forEach(location -> {
+        locations.stream().filter(srManager::isMasterOf).forEach(location -> {
             Sets.difference(prevIps, newIps).forEach(ip ->
                     processRoutingRule(location.deviceId(), location.port(), mac, vlanId, ip, true)
             );
@@ -378,20 +379,9 @@
 
         log.info("{} routing rule for {} at {}", revoke ? "Revoking" : "Populating", ip, location);
         if (revoke) {
-            srManager.routingRulePopulator.revokeRoute(deviceId, ip.toIpPrefix(), mac, vlanId, port);
+            srManager.defaultRoutingHandler.revokeRoute(deviceId, ip.toIpPrefix(), mac, vlanId, port);
         } else {
-            srManager.routingRulePopulator.populateRoute(deviceId, ip.toIpPrefix(), mac, vlanId, port);
+            srManager.defaultRoutingHandler.populateRoute(deviceId, ip.toIpPrefix(), mac, vlanId, port);
         }
     }
-
-    /**
-     * Determine if current instance is the master of given connect point.
-     *
-     * @param cp connect point
-     * @return true if current instance is the master of given connect point
-     */
-    private boolean isMasterOf(ConnectPoint cp) {
-        log.debug(NOT_MASTER, cp);
-        return srManager.mastershipService.isLocalMaster(cp.deviceId());
-    }
 }
diff --git a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/RouteHandler.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/RouteHandler.java
index 214ba6b..c80bc09 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/RouteHandler.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/RouteHandler.java
@@ -16,20 +16,33 @@
 
 package org.onosproject.segmentrouting;
 
-import com.google.common.collect.ImmutableSet;
+import com.google.common.cache.Cache;
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.RemovalCause;
+import com.google.common.cache.RemovalNotification;
 import com.google.common.collect.Sets;
 
 import org.onlab.packet.IpPrefix;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
 import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.HostLocation;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.host.HostEvent;
 import org.onosproject.routeservice.ResolvedRoute;
 import org.onosproject.routeservice.RouteEvent;
 import org.onosproject.net.DeviceId;
+import org.onosproject.routeservice.RouteInfo;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.util.Collection;
 import java.util.Objects;
+import java.util.Optional;
+import java.util.Set;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
 
 /**
  * Handles RouteEvent and manages routing entries.
@@ -38,8 +51,35 @@
     private static final Logger log = LoggerFactory.getLogger(RouteHandler.class);
     private final SegmentRoutingManager srManager;
 
+    private static final int WAIT_TIME_MS = 1000;
+    /**
+     * The routeEventCache is implemented to avoid race condition by giving more time to the
+     * underlying flow subsystem to process previous populateSubnet call.
+     */
+    private Cache<IpPrefix, RouteEvent> routeEventCache = CacheBuilder.newBuilder()
+            .expireAfterWrite(WAIT_TIME_MS, TimeUnit.MILLISECONDS)
+            .removalListener((RemovalNotification<IpPrefix, RouteEvent> notification) -> {
+                IpPrefix prefix = notification.getKey();
+                RouteEvent routeEvent = notification.getValue();
+                RemovalCause cause = notification.getCause();
+                log.debug("routeEventCache removal event. prefix={}, routeEvent={}, cause={}",
+                        prefix, routeEvent, cause);
+
+                switch (notification.getCause()) {
+                    case REPLACED:
+                    case EXPIRED:
+                        dequeueRouteEvent(routeEvent);
+                        break;
+                    default:
+                        break;
+                }
+            }).build();
+
     RouteHandler(SegmentRoutingManager srManager) {
         this.srManager = srManager;
+
+        Executors.newSingleThreadScheduledExecutor()
+                .scheduleAtFixedRate(routeEventCache::cleanUp, 0, WAIT_TIME_MS, TimeUnit.MILLISECONDS);
     }
 
     protected void init(DeviceId deviceId) {
@@ -56,70 +96,239 @@
     }
 
     void processRouteAdded(RouteEvent event) {
-        log.info("processRouteAdded {}", event);
-        processRouteAddedInternal(event.subject());
+        enqueueRouteEvent(event);
     }
 
     private void processRouteAddedInternal(ResolvedRoute route) {
+        processRouteAddedInternal(Sets.newHashSet(route));
+    }
+
+    private void processRouteAddedInternal(Collection<ResolvedRoute> routes) {
         if (!isReady()) {
-            log.info("System is not ready. Skip adding route for {}", route.prefix());
+            log.info("System is not ready. Skip adding route for {}", routes);
             return;
         }
 
-        IpPrefix prefix = route.prefix();
-        MacAddress nextHopMac = route.nextHopMac();
-        VlanId nextHopVlan = route.nextHopVlan();
-        ConnectPoint location = srManager.nextHopLocations(route).stream().findFirst().orElse(null);
+        log.info("processRouteAddedInternal. routes={}", routes);
 
-        if (location == null) {
-            log.info("{} ignored. Cannot find nexthop location", prefix);
-            return;
-        }
+        Set<ConnectPoint> allLocations = Sets.newHashSet();
+        Set<IpPrefix> allPrefixes = Sets.newHashSet();
+        routes.forEach(route -> {
+            allLocations.addAll(srManager.nextHopLocations(route));
+            allPrefixes.add(route.prefix());
+        });
+        log.debug("RouteAdded. populateSubnet {}, {}", allLocations, allPrefixes);
+        srManager.defaultRoutingHandler.populateSubnet(allLocations, allPrefixes);
 
-        srManager.deviceConfiguration.addSubnet(location, prefix);
-        // XXX need to handle the case where there are two connectpoints
-        srManager.defaultRoutingHandler.populateSubnet(Sets.newHashSet(location),
-                                                       Sets.newHashSet(prefix));
-        srManager.routingRulePopulator.populateRoute(location.deviceId(), prefix,
-                nextHopMac, nextHopVlan, location.port());
+        routes.forEach(route -> {
+            IpPrefix prefix = route.prefix();
+            MacAddress nextHopMac = route.nextHopMac();
+            VlanId nextHopVlan = route.nextHopVlan();
+            Set<ConnectPoint> locations = srManager.nextHopLocations(route);
+
+            locations.forEach(location -> {
+                log.debug("RouteAdded. addSubnet {}, {}", location, prefix);
+                srManager.deviceConfiguration.addSubnet(location, prefix);
+                log.debug("RouteAdded populateRoute {}, {}, {}, {}", location, prefix, nextHopMac, nextHopVlan);
+                srManager.defaultRoutingHandler.populateRoute(location.deviceId(), prefix,
+                        nextHopMac, nextHopVlan, location.port());
+            });
+        });
     }
 
     void processRouteUpdated(RouteEvent event) {
-        log.info("processRouteUpdated {}", event);
-        processRouteRemovedInternal(event.prevSubject());
-        processRouteAddedInternal(event.subject());
+        enqueueRouteEvent(event);
+    }
+
+    void processAlternativeRoutesChanged(RouteEvent event) {
+        enqueueRouteEvent(event);
+    }
+
+    private void processRouteUpdatedInternal(Set<ResolvedRoute> routes, Set<ResolvedRoute> oldRoutes) {
+        if (!isReady()) {
+            log.info("System is not ready. Skip updating route for {} -> {}", oldRoutes, routes);
+            return;
+        }
+
+        log.info("processRouteUpdatedInternal. routes={}, oldRoutes={}", routes, oldRoutes);
+
+        Set<ConnectPoint> allLocations = Sets.newHashSet();
+        Set<IpPrefix> allPrefixes = Sets.newHashSet();
+        routes.forEach(route -> {
+            allLocations.addAll(srManager.nextHopLocations(route));
+            allPrefixes.add(route.prefix());
+        });
+        log.debug("RouteUpdated. populateSubnet {}, {}", allLocations, allPrefixes);
+        srManager.defaultRoutingHandler.populateSubnet(allLocations, allPrefixes);
+
+
+        Set<ResolvedRoute> toBeRemoved = Sets.difference(oldRoutes, routes).immutableCopy();
+        Set<ResolvedRoute> toBeAdded = Sets.difference(routes, oldRoutes).immutableCopy();
+
+        toBeRemoved.forEach(route -> {
+            srManager.nextHopLocations(route).forEach(oldLocation -> {
+               if (toBeAdded.stream().map(srManager::nextHopLocations)
+                       .flatMap(Set::stream).map(ConnectPoint::deviceId)
+                       .noneMatch(deviceId -> deviceId.equals(oldLocation.deviceId()))) {
+                   IpPrefix prefix = route.prefix();
+                   MacAddress nextHopMac = route.nextHopMac();
+                   VlanId nextHopVlan = route.nextHopVlan();
+
+                   log.debug("RouteUpdated. removeSubnet {}, {}", oldLocation, prefix);
+                   srManager.deviceConfiguration.removeSubnet(oldLocation, prefix);
+                   log.debug("RouteUpdated. revokeRoute {}, {}, {}, {}", oldLocation, prefix, nextHopMac, nextHopVlan);
+                   srManager.defaultRoutingHandler.revokeRoute(oldLocation.deviceId(), prefix,
+                           nextHopMac, nextHopVlan, oldLocation.port());
+               }
+            });
+        });
+
+        toBeAdded.forEach(route -> {
+            IpPrefix prefix = route.prefix();
+            MacAddress nextHopMac = route.nextHopMac();
+            VlanId nextHopVlan = route.nextHopVlan();
+            Set<ConnectPoint> locations = srManager.nextHopLocations(route);
+
+            locations.forEach(location -> {
+                log.debug("RouteUpdated. addSubnet {}, {}", location, prefix);
+                srManager.deviceConfiguration.addSubnet(location, prefix);
+                log.debug("RouteUpdated. populateRoute {}, {}, {}, {}", location, prefix, nextHopMac, nextHopVlan);
+                srManager.defaultRoutingHandler.populateRoute(location.deviceId(), prefix,
+                        nextHopMac, nextHopVlan, location.port());
+            });
+        });
+
     }
 
     void processRouteRemoved(RouteEvent event) {
-        log.info("processRouteRemoved {}", event);
-        processRouteRemovedInternal(event.subject());
+        enqueueRouteEvent(event);
     }
 
-    private void processRouteRemovedInternal(ResolvedRoute route) {
+    private void processRouteRemovedInternal(Collection<ResolvedRoute> routes) {
         if (!isReady()) {
-            log.info("System is not ready. Skip removing route for {}", route.prefix());
+            log.info("System is not ready. Skip removing route for {}", routes);
             return;
         }
 
-        IpPrefix prefix = route.prefix();
-        MacAddress nextHopMac = route.nextHopMac();
-        VlanId nextHopVlan = route.nextHopVlan();
-        ConnectPoint location = srManager.nextHopLocations(route).stream().findFirst().orElse(null);
+        log.info("processRouteRemovedInternal. routes={}", routes);
 
-        if (location == null) {
-            log.info("{} ignored. Cannot find nexthop location", prefix);
-            return;
-        }
+        Set<IpPrefix> allPrefixes = Sets.newHashSet();
+        routes.forEach(route -> {
+            allPrefixes.add(route.prefix());
+        });
+        log.debug("RouteRemoved. revokeSubnet {}", allPrefixes);
+        srManager.defaultRoutingHandler.revokeSubnet(allPrefixes);
 
-        srManager.deviceConfiguration.removeSubnet(location, prefix);
-        srManager.defaultRoutingHandler.revokeSubnet(ImmutableSet.of(prefix));
-        srManager.routingRulePopulator.revokeRoute(
-                location.deviceId(), prefix, nextHopMac, nextHopVlan, location.port());
+        routes.forEach(route -> {
+            IpPrefix prefix = route.prefix();
+            MacAddress nextHopMac = route.nextHopMac();
+            VlanId nextHopVlan = route.nextHopVlan();
+            Set<ConnectPoint> locations = srManager.nextHopLocations(route);
+
+            locations.forEach(location -> {
+                log.debug("RouteRemoved. removeSubnet {}, {}", location, prefix);
+                srManager.deviceConfiguration.removeSubnet(location, prefix);
+                log.debug("RouteRemoved. revokeRoute {}, {}, {}, {}", location, prefix, nextHopMac, nextHopVlan);
+                srManager.defaultRoutingHandler.revokeRoute(location.deviceId(), prefix,
+                        nextHopMac, nextHopVlan, location.port());
+
+                // Also remove redirection flows on the pair device if exists.
+                Optional<DeviceId> pairDeviceId = srManager.getPairDeviceId(location.deviceId());
+                Optional<PortNumber> pairLocalPort = srManager.getPairLocalPorts(location.deviceId());
+                if (pairDeviceId.isPresent() && pairLocalPort.isPresent()) {
+                    // NOTE: Since the pairLocalPort is trunk port, use assigned vlan of original port
+                    //       when the host is untagged
+                    VlanId vlanId = Optional.ofNullable(srManager.getInternalVlanId(location)).orElse(nextHopVlan);
+
+                    log.debug("RouteRemoved. revokeRoute {}, {}, {}, {}", location, prefix, nextHopMac, nextHopVlan);
+                    srManager.defaultRoutingHandler.revokeRoute(pairDeviceId.get(), prefix,
+                            nextHopMac, vlanId, pairLocalPort.get());
+                }
+            });
+        });
+    }
+
+    void processHostMovedEvent(HostEvent event) {
+        log.info("processHostMovedEvent {}", event);
+        MacAddress hostMac = event.subject().mac();
+        VlanId hostVlanId = event.subject().vlan();
+
+        affectedRoutes(hostMac, hostVlanId).forEach(affectedRoute -> {
+            IpPrefix prefix = affectedRoute.prefix();
+            Set<HostLocation> prevLocations = event.prevSubject().locations();
+            Set<HostLocation> newLocations = event.subject().locations();
+
+            // For each old location
+            Sets.difference(prevLocations, newLocations).stream().filter(srManager::isMasterOf)
+                    .forEach(prevLocation -> {
+                // Redirect the flows to pair link if configured
+                // Note: Do not continue removing any rule
+                Optional<DeviceId> pairDeviceId = srManager.getPairDeviceId(prevLocation.deviceId());
+                Optional<PortNumber> pairLocalPort = srManager.getPairLocalPorts(prevLocation.deviceId());
+                if (pairDeviceId.isPresent() && pairLocalPort.isPresent() && newLocations.stream()
+                        .anyMatch(location -> location.deviceId().equals(pairDeviceId.get()))) {
+                    // NOTE: Since the pairLocalPort is trunk port, use assigned vlan of original port
+                    //       when the host is untagged
+                    VlanId vlanId = Optional.ofNullable(srManager.getInternalVlanId(prevLocation)).orElse(hostVlanId);
+                    log.debug("HostMoved. populateRoute {}, {}, {}, {}", prevLocation, prefix, hostMac, vlanId);
+                    srManager.defaultRoutingHandler.populateRoute(prevLocation.deviceId(), prefix,
+                            hostMac, vlanId, pairLocalPort.get());
+                    return;
+                }
+
+                // No pair information supplied. Remove route
+                log.debug("HostMoved. revokeRoute {}, {}, {}, {}", prevLocation, prefix, hostMac, hostVlanId);
+                srManager.defaultRoutingHandler.revokeRoute(prevLocation.deviceId(), prefix,
+                        hostMac, hostVlanId, prevLocation.port());
+            });
+
+            // For each new location, add all new IPs.
+            Sets.difference(newLocations, prevLocations).stream().filter(srManager::isMasterOf)
+                    .forEach(newLocation -> {
+                log.debug("HostMoved. populateRoute {}, {}, {}, {}", newLocation, prefix, hostMac, hostVlanId);
+                srManager.defaultRoutingHandler.populateRoute(newLocation.deviceId(), prefix,
+                        hostMac, hostVlanId, newLocation.port());
+            });
+
+        });
+    }
+
+    private Set<ResolvedRoute> affectedRoutes(MacAddress mac, VlanId vlanId) {
+        return srManager.routeService.getRouteTables().stream()
+                .map(routeTableId -> srManager.routeService.getRoutes(routeTableId))
+                .flatMap(Collection::stream)
+                .map(RouteInfo::allRoutes)
+                .flatMap(Collection::stream)
+                .filter(resolvedRoute -> mac.equals(resolvedRoute.nextHopMac()) &&
+                        vlanId.equals(resolvedRoute.nextHopVlan())).collect(Collectors.toSet());
     }
 
     private boolean isReady() {
         return Objects.nonNull(srManager.deviceConfiguration) &&
-                Objects.nonNull(srManager.defaultRoutingHandler) &&
-                Objects.nonNull(srManager.routingRulePopulator);
+                Objects.nonNull(srManager.defaultRoutingHandler);
+    }
+
+    void enqueueRouteEvent(RouteEvent routeEvent) {
+        log.debug("Enqueue routeEvent {}", routeEvent);
+        routeEventCache.put(routeEvent.subject().prefix(), routeEvent);
+    }
+
+    void dequeueRouteEvent(RouteEvent routeEvent) {
+        log.debug("Dequeue routeEvent {}", routeEvent);
+        switch (routeEvent.type()) {
+            case ROUTE_ADDED:
+                processRouteAddedInternal(routeEvent.alternatives());
+                break;
+            case ROUTE_REMOVED:
+                processRouteRemovedInternal(routeEvent.alternatives());
+                break;
+            case ROUTE_UPDATED:
+            case ALTERNATIVE_ROUTES_CHANGED:
+                processRouteUpdatedInternal(Sets.newHashSet(routeEvent.alternatives()),
+                        Sets.newHashSet(routeEvent.prevAlternatives()));
+                break;
+            default:
+                break;
+        }
     }
 }
diff --git a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/RoutingRulePopulator.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/RoutingRulePopulator.java
index dd11423..3fb38ba 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/RoutingRulePopulator.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/RoutingRulePopulator.java
@@ -119,7 +119,7 @@
      * @param hostVlanId Vlan ID of the nexthop
      * @param outPort port where the next hop attaches to
      */
-    public void populateRoute(DeviceId deviceId, IpPrefix prefix,
+    void populateRoute(DeviceId deviceId, IpPrefix prefix,
                               MacAddress hostMac, VlanId hostVlanId, PortNumber outPort) {
         log.debug("Populate direct routing entry for route {} at {}:{}",
                 prefix, deviceId, outPort);
@@ -136,9 +136,11 @@
                     + "to error for dev:{} route:{}", deviceId, prefix);
             return;
         }
+
+        int nextId = fwdBuilder.add().nextId();
         ObjectiveContext context = new DefaultObjectiveContext(
-                (objective) -> log.debug("Direct routing rule for route {} populated",
-                                         prefix),
+                (objective) -> log.debug("Direct routing rule for route {} populated. nextId={}",
+                                         prefix, nextId),
                 (objective, error) ->
                         log.warn("Failed to populate direct routing rule for route {}: {}",
                                  prefix, error));
@@ -155,7 +157,7 @@
      * @param hostVlanId Vlan ID of the nexthop
      * @param outPort port that next hop attaches to
      */
-    public void revokeRoute(DeviceId deviceId, IpPrefix prefix,
+    void revokeRoute(DeviceId deviceId, IpPrefix prefix,
             MacAddress hostMac, VlanId hostVlanId, PortNumber outPort) {
         log.debug("Revoke IP table entry for route {} at {}:{}",
                 prefix, deviceId, outPort);
diff --git a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
index 6be675a..79bd8d3 100644
--- a/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
+++ b/apps/segmentrouting/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
@@ -130,6 +130,7 @@
 public class SegmentRoutingManager implements SegmentRoutingService {
 
     private static Logger log = LoggerFactory.getLogger(SegmentRoutingManager.class);
+    private static final String NOT_MASTER = "Current instance is not the master of {}. Ignore.";
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
     private ComponentConfigService compCfgService;
@@ -700,6 +701,20 @@
     }
 
     /**
+     * Determine if current instance is the master of given connect point.
+     *
+     * @param cp connect point
+     * @return true if current instance is the master of given connect point
+     */
+    boolean isMasterOf(ConnectPoint cp) {
+        boolean isMaster = mastershipService.isLocalMaster(cp.deviceId());
+        if (!isMaster) {
+            log.debug(NOT_MASTER, cp);
+        }
+        return isMaster;
+    }
+
+    /**
      * Returns locations of given resolved route.
      *
      * @param resolvedRoute resolved route
@@ -1539,6 +1554,7 @@
                     break;
                 case HOST_MOVED:
                     hostHandler.processHostMovedEvent(event);
+                    routeHandler.processHostMovedEvent(event);
                     break;
                 case HOST_REMOVED:
                     hostHandler.processHostRemovedEvent(event);
@@ -1587,6 +1603,9 @@
                 case ROUTE_REMOVED:
                     routeHandler.processRouteRemoved(event);
                     break;
+                case ALTERNATIVE_ROUTES_CHANGED:
+                    routeHandler.processAlternativeRoutesChanged(event);
+                    break;
                 default:
                     break;
             }
diff --git a/apps/segmentrouting/src/test/java/org/onosproject/segmentrouting/HostHandlerTest.java b/apps/segmentrouting/src/test/java/org/onosproject/segmentrouting/HostHandlerTest.java
index 3ad2d52..3e576b95 100644
--- a/apps/segmentrouting/src/test/java/org/onosproject/segmentrouting/HostHandlerTest.java
+++ b/apps/segmentrouting/src/test/java/org/onosproject/segmentrouting/HostHandlerTest.java
@@ -60,6 +60,7 @@
             Maps.newConcurrentMap();
     private static final Map<MockRoutingTableKey, MockRoutingTableValue> ROUTING_TABLE =
             Maps.newConcurrentMap();
+    private static final Map<ConnectPoint, Set<IpPrefix>> SUBNET_TABLE = Maps.newConcurrentMap();
     // Mocked Next Id
     private static final Map<Integer, TrafficTreatment> NEXT_TABLE = Maps.newConcurrentMap();
 
@@ -191,6 +192,7 @@
         srManager.deviceConfiguration = new DeviceConfiguration(srManager);
         srManager.flowObjectiveService = new MockFlowObjectiveService(BRIDGING_TABLE, NEXT_TABLE);
         srManager.routingRulePopulator = new MockRoutingRulePopulator(srManager, ROUTING_TABLE);
+        srManager.defaultRoutingHandler = new MockDefaultRoutingHandler(srManager, SUBNET_TABLE);
         srManager.interfaceService = new MockInterfaceService(INTERFACES);
         srManager.mastershipService = new MockMastershipService(LOCAL_DEVICES);
         srManager.hostService = new MockHostService(HOSTS);
diff --git a/apps/segmentrouting/src/test/java/org/onosproject/segmentrouting/MockDefaultRoutingHandler.java b/apps/segmentrouting/src/test/java/org/onosproject/segmentrouting/MockDefaultRoutingHandler.java
index a69d5e7..ec07238 100644
--- a/apps/segmentrouting/src/test/java/org/onosproject/segmentrouting/MockDefaultRoutingHandler.java
+++ b/apps/segmentrouting/src/test/java/org/onosproject/segmentrouting/MockDefaultRoutingHandler.java
@@ -36,6 +36,15 @@
 
     @Override
     protected void populateSubnet(Set<ConnectPoint> cpts, Set<IpPrefix> subnets) {
+        subnetTable.forEach((k, v) -> {
+            if (!cpts.contains(k)) {
+                subnetTable.get(k).removeAll(subnets);
+                if (subnetTable.get(k).isEmpty()) {
+                    subnetTable.remove(k);
+                }
+            }
+        });
+
         cpts.forEach(cpt -> subnetTable.put(cpt, subnets));
     }
 
diff --git a/apps/segmentrouting/src/test/java/org/onosproject/segmentrouting/MockRouteService.java b/apps/segmentrouting/src/test/java/org/onosproject/segmentrouting/MockRouteService.java
index 14e2166..7927636 100644
--- a/apps/segmentrouting/src/test/java/org/onosproject/segmentrouting/MockRouteService.java
+++ b/apps/segmentrouting/src/test/java/org/onosproject/segmentrouting/MockRouteService.java
@@ -16,29 +16,44 @@
 
 package org.onosproject.segmentrouting;
 
-import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Sets;
+import org.onlab.packet.IpAddress;
+import org.onlab.packet.IpPrefix;
+import org.onlab.packet.MacAddress;
+import org.onlab.packet.VlanId;
+import org.onosproject.routeservice.ResolvedRoute;
+import org.onosproject.routeservice.Route;
 import org.onosproject.routeservice.RouteInfo;
 import org.onosproject.routeservice.RouteServiceAdapter;
 import org.onosproject.routeservice.RouteTableId;
 
 import java.util.Collection;
-import java.util.Set;
+import java.util.Map;
+import java.util.stream.Collectors;
 
 /**
  * Mock Route Service.
  * We assume there is only one routing table named "default".
  */
 public class MockRouteService extends RouteServiceAdapter {
-    private Set<RouteInfo> routes;
+    private Map<MockRoutingTableKey, MockRoutingTableValue> routingTable;
 
-    MockRouteService(Set<RouteInfo> routes) {
-        this.routes = ImmutableSet.copyOf(routes);
+    MockRouteService(Map<MockRoutingTableKey, MockRoutingTableValue> routingTable) {
+        this.routingTable = routingTable;
     }
 
     @Override
     public Collection<RouteInfo> getRoutes(RouteTableId id) {
-        return routes;
+        return routingTable.entrySet().stream().map(e -> {
+            IpPrefix prefix = e.getKey().ipPrefix;
+            IpAddress nextHop = IpAddress.valueOf(0); // dummy
+            MacAddress mac = e.getValue().macAddress;
+            VlanId vlan = e.getValue().vlanId;
+            Route route = new Route(Route.Source.STATIC, prefix, nextHop);
+            ResolvedRoute rr = new ResolvedRoute(route, mac, vlan);
+
+            return new RouteInfo(prefix, rr, Sets.newHashSet(rr));
+        }).collect(Collectors.toSet());
     }
 
     @Override
diff --git a/apps/segmentrouting/src/test/java/org/onosproject/segmentrouting/RouteHandlerTest.java b/apps/segmentrouting/src/test/java/org/onosproject/segmentrouting/RouteHandlerTest.java
index 383f800..775e5ee 100644
--- a/apps/segmentrouting/src/test/java/org/onosproject/segmentrouting/RouteHandlerTest.java
+++ b/apps/segmentrouting/src/test/java/org/onosproject/segmentrouting/RouteHandlerTest.java
@@ -16,6 +16,8 @@
 
 package org.onosproject.segmentrouting;
 
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.common.collect.Maps;
 import com.google.common.collect.Sets;
 import org.junit.Before;
@@ -24,21 +26,25 @@
 import org.onlab.packet.IpPrefix;
 import org.onlab.packet.MacAddress;
 import org.onlab.packet.VlanId;
+import org.onosproject.net.config.ConfigApplyDelegate;
 import org.onosproject.net.ConnectPoint;
 import org.onosproject.net.DefaultHost;
 import org.onosproject.net.DeviceId;
 import org.onosproject.net.Host;
 import org.onosproject.net.HostId;
 import org.onosproject.net.HostLocation;
+import org.onosproject.net.PortNumber;
 import org.onosproject.net.config.NetworkConfigRegistryAdapter;
 import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.net.host.HostEvent;
+import org.onosproject.net.host.HostService;
 import org.onosproject.net.intf.Interface;
 import org.onosproject.net.provider.ProviderId;
 import org.onosproject.routeservice.ResolvedRoute;
 import org.onosproject.routeservice.Route;
 import org.onosproject.routeservice.RouteEvent;
-import org.onosproject.routeservice.RouteInfo;
 import org.onosproject.segmentrouting.config.DeviceConfiguration;
+import org.onosproject.segmentrouting.config.SegmentRoutingDeviceConfig;
 
 import java.util.Map;
 import java.util.Set;
@@ -50,6 +56,7 @@
  */
 public class RouteHandlerTest {
     private RouteHandler routeHandler;
+    private HostService hostService;
 
     // Mocked routing and bridging tables
     private static final Map<MockBridgingTableKey, MockBridgingTableValue> BRIDGING_TABLE =
@@ -61,6 +68,8 @@
     private static final Map<Integer, TrafficTreatment> NEXT_TABLE = Maps.newConcurrentMap();
 
     private static final IpPrefix P1 = IpPrefix.valueOf("10.0.0.0/24");
+
+    // Single homed router 1
     private static final IpAddress N1 = IpAddress.valueOf("10.0.1.254");
     private static final MacAddress M1 = MacAddress.valueOf("00:00:00:00:00:01");
     private static final VlanId V1 = VlanId.vlanId((short) 1);
@@ -68,48 +77,61 @@
     private static final Route R1 = new Route(Route.Source.STATIC, P1, N1);
     private static final ResolvedRoute RR1 = new ResolvedRoute(R1, M1, V1);
 
+    // Single homed router 2
     private static final IpAddress N2 = IpAddress.valueOf("10.0.2.254");
     private static final MacAddress M2 = MacAddress.valueOf("00:00:00:00:00:02");
     private static final VlanId V2 = VlanId.vlanId((short) 2);
-    private static final ConnectPoint CP2 = ConnectPoint.deviceConnectPoint("of:0000000000000001/2");
+    private static final ConnectPoint CP2 = ConnectPoint.deviceConnectPoint("of:0000000000000002/2");
     private static final Route R2 = new Route(Route.Source.STATIC, P1, N2);
     private static final ResolvedRoute RR2 = new ResolvedRoute(R2, M2, V2);
 
-    private static final RouteInfo RI1 = new RouteInfo(P1, RR1, Sets.newHashSet(RR1));
+    // Dual homed router 1
+    private static final IpAddress N3 = IpAddress.valueOf("10.0.3.254");
+    private static final MacAddress M3 = MacAddress.valueOf("00:00:00:00:00:03");
+    private static final VlanId V3 = VlanId.vlanId((short) 3);
+    private static final Route R3 = new Route(Route.Source.STATIC, P1, N3);
+    private static final ResolvedRoute RR3 = new ResolvedRoute(R3, M3, V3);
 
+    // Hosts
     private static final Host H1 = new DefaultHost(ProviderId.NONE, HostId.hostId(M1, V1), M1, V1,
             Sets.newHashSet(new HostLocation(CP1, 0)), Sets.newHashSet(N1), false);
     private static final Host H2 = new DefaultHost(ProviderId.NONE, HostId.hostId(M2, V2), M2, V2,
             Sets.newHashSet(new HostLocation(CP2, 0)), Sets.newHashSet(N2), false);
+    private static final Host H3D = new DefaultHost(ProviderId.NONE, HostId.hostId(M3, V3), M3, V3,
+            Sets.newHashSet(new HostLocation(CP1, 0), new HostLocation(CP2, 0)), Sets.newHashSet(N3), false);
+    private static final Host H3S = new DefaultHost(ProviderId.NONE, HostId.hostId(M3, V3), M3, V3,
+            Sets.newHashSet(new HostLocation(CP1, 0)), Sets.newHashSet(N3), false);
+
+    // Pair Local Port
+    private static final PortNumber P9 = PortNumber.portNumber(9);
 
     // A set of hosts
-    private static final Set<Host> HOSTS = Sets.newHashSet(H1, H2);
+    private static final Set<Host> HOSTS = Sets.newHashSet(H1, H2, H3D);
+    private static final Set<Host> HOSTS_ONE_FAIL = Sets.newHashSet(H1, H2, H3S);
+    private static final Set<Host> HOSTS_BOTH_FAIL = Sets.newHashSet(H1, H2);
     // A set of devices of which we have mastership
-    private static final Set<DeviceId> LOCAL_DEVICES = Sets.newHashSet();
+    private static final Set<DeviceId> LOCAL_DEVICES = Sets.newHashSet(CP1.deviceId(), CP2.deviceId());
     // A set of interfaces
     private static final Set<Interface> INTERFACES = Sets.newHashSet();
-    // A set of routes
-    private static final Set<RouteInfo> ROUTE_INFOS = Sets.newHashSet(RI1);
 
     @Before
     public void setUp() throws Exception {
-// TODO Initialize pairDevice and pairLocalPort config
-//        ObjectMapper mapper = new ObjectMapper();
-//        ConfigApplyDelegate delegate = config -> {};
-//
-//        SegmentRoutingDeviceConfig dev3Config = new SegmentRoutingDeviceConfig();
-//        JsonNode dev3Tree = mapper.createObjectNode();
-//        dev3Config.init(DEV3, "host-handler-test", dev3Tree, mapper, delegate);
-//        dev3Config.setPairDeviceId(DEV4).setPairLocalPort(P9);
-//
-//        SegmentRoutingDeviceConfig dev4Config = new SegmentRoutingDeviceConfig();
-//        JsonNode dev4Tree = mapper.createObjectNode();
-//        dev4Config.init(DEV4, "host-handler-test", dev4Tree, mapper, delegate);
-//        dev4Config.setPairDeviceId(DEV3).setPairLocalPort(P9);
+        ObjectMapper mapper = new ObjectMapper();
+        ConfigApplyDelegate delegate = config -> { };
+
+        SegmentRoutingDeviceConfig dev1Config = new SegmentRoutingDeviceConfig();
+        JsonNode dev1Tree = mapper.createObjectNode();
+        dev1Config.init(CP1.deviceId(), "host-handler-test", dev1Tree, mapper, delegate);
+        dev1Config.setPairDeviceId(CP2.deviceId()).setPairLocalPort(P9);
+
+        SegmentRoutingDeviceConfig dev2Config = new SegmentRoutingDeviceConfig();
+        JsonNode dev2Tree = mapper.createObjectNode();
+        dev2Config.init(CP2.deviceId(), "host-handler-test", dev2Tree, mapper, delegate);
+        dev2Config.setPairDeviceId(CP1.deviceId()).setPairLocalPort(P9);
 
         MockNetworkConfigRegistry mockNetworkConfigRegistry = new MockNetworkConfigRegistry();
-//        mockNetworkConfigRegistry.applyConfig(dev3Config);
-//        mockNetworkConfigRegistry.applyConfig(dev4Config);
+        mockNetworkConfigRegistry.applyConfig(dev1Config);
+        mockNetworkConfigRegistry.applyConfig(dev2Config);
 
         // Initialize Segment Routing Manager
         SegmentRoutingManager srManager = new MockSegmentRoutingManager(NEXT_TABLE);
@@ -120,11 +142,18 @@
         srManager.defaultRoutingHandler = new MockDefaultRoutingHandler(srManager, SUBNET_TABLE);
         srManager.interfaceService = new MockInterfaceService(INTERFACES);
         srManager.mastershipService = new MockMastershipService(LOCAL_DEVICES);
-        srManager.hostService = new MockHostService(HOSTS);
+        hostService = new MockHostService(HOSTS);
+        srManager.hostService = hostService;
         srManager.cfgService = mockNetworkConfigRegistry;
-        srManager.routeService = new MockRouteService(ROUTE_INFOS);
+        srManager.routeService = new MockRouteService(ROUTING_TABLE);
 
-        routeHandler = new RouteHandler(srManager);
+        routeHandler = new RouteHandler(srManager) {
+            // routeEventCache is not necessary for unit tests
+            @Override
+            void enqueueRouteEvent(RouteEvent routeEvent) {
+                dequeueRouteEvent(routeEvent);
+            }
+        };
 
         ROUTING_TABLE.clear();
         BRIDGING_TABLE.clear();
@@ -133,6 +162,10 @@
 
     @Test
     public void init() throws Exception {
+        MockRoutingTableKey rtk = new MockRoutingTableKey(CP1.deviceId(), P1);
+        MockRoutingTableValue rtv = new MockRoutingTableValue(CP1.port(), M1, V1);
+        ROUTING_TABLE.put(rtk, rtv);
+
         routeHandler.init(CP1.deviceId());
 
         assertEquals(1, ROUTING_TABLE.size());
@@ -147,7 +180,7 @@
 
     @Test
     public void processRouteAdded() throws Exception {
-        RouteEvent re = new RouteEvent(RouteEvent.Type.ROUTE_ADDED, RR1);
+        RouteEvent re = new RouteEvent(RouteEvent.Type.ROUTE_ADDED, RR1, Sets.newHashSet(RR1));
         routeHandler.processRouteAdded(re);
 
         assertEquals(1, ROUTING_TABLE.size());
@@ -164,11 +197,12 @@
     public void processRouteUpdated() throws Exception {
         processRouteAdded();
 
-        RouteEvent re = new RouteEvent(RouteEvent.Type.ROUTE_UPDATED, RR2, RR1);
+        RouteEvent re = new RouteEvent(RouteEvent.Type.ROUTE_UPDATED, RR2, RR1, Sets.newHashSet(RR2),
+                Sets.newHashSet(RR1));
         routeHandler.processRouteUpdated(re);
 
         assertEquals(1, ROUTING_TABLE.size());
-        MockRoutingTableValue rtv2 = ROUTING_TABLE.get(new MockRoutingTableKey(CP1.deviceId(), P1));
+        MockRoutingTableValue rtv2 = ROUTING_TABLE.get(new MockRoutingTableKey(CP2.deviceId(), P1));
         assertEquals(M2, rtv2.macAddress);
         assertEquals(V2, rtv2.vlanId);
         assertEquals(CP2.port(), rtv2.portNumber);
@@ -181,7 +215,148 @@
     public void processRouteRemoved() throws Exception {
         processRouteAdded();
 
-        RouteEvent re = new RouteEvent(RouteEvent.Type.ROUTE_REMOVED, RR1);
+        RouteEvent re = new RouteEvent(RouteEvent.Type.ROUTE_REMOVED, RR1, Sets.newHashSet(RR1));
+        routeHandler.processRouteRemoved(re);
+
+        assertEquals(0, ROUTING_TABLE.size());
+        assertEquals(0, SUBNET_TABLE.size());
+    }
+
+    @Test
+    public void testTwoSingleHomedAdded() throws Exception {
+        RouteEvent re = new RouteEvent(RouteEvent.Type.ROUTE_ADDED, RR1, Sets.newHashSet(RR1, RR2));
+        routeHandler.processRouteAdded(re);
+
+        assertEquals(2, ROUTING_TABLE.size());
+        MockRoutingTableValue rtv1 = ROUTING_TABLE.get(new MockRoutingTableKey(CP1.deviceId(), P1));
+        MockRoutingTableValue rtv2 = ROUTING_TABLE.get(new MockRoutingTableKey(CP2.deviceId(), P1));
+        assertEquals(M1, rtv1.macAddress);
+        assertEquals(M2, rtv2.macAddress);
+        assertEquals(V1, rtv1.vlanId);
+        assertEquals(V2, rtv2.vlanId);
+        assertEquals(CP1.port(), rtv1.portNumber);
+        assertEquals(CP2.port(), rtv2.portNumber);
+
+        assertEquals(2, SUBNET_TABLE.size());
+        assertTrue(SUBNET_TABLE.get(CP1).contains(P1));
+        assertTrue(SUBNET_TABLE.get(CP2).contains(P1));
+    }
+
+    @Test
+    public void testOneDualHomedAdded() throws Exception {
+        RouteEvent re = new RouteEvent(RouteEvent.Type.ROUTE_ADDED, RR3, Sets.newHashSet(RR3));
+        routeHandler.processRouteAdded(re);
+
+        assertEquals(2, ROUTING_TABLE.size());
+        MockRoutingTableValue rtv1 = ROUTING_TABLE.get(new MockRoutingTableKey(CP1.deviceId(), P1));
+        MockRoutingTableValue rtv2 = ROUTING_TABLE.get(new MockRoutingTableKey(CP2.deviceId(), P1));
+        assertEquals(M3, rtv1.macAddress);
+        assertEquals(M3, rtv2.macAddress);
+        assertEquals(V3, rtv1.vlanId);
+        assertEquals(V3, rtv2.vlanId);
+        assertEquals(CP1.port(), rtv1.portNumber);
+        assertEquals(CP2.port(), rtv2.portNumber);
+
+        assertEquals(2, SUBNET_TABLE.size());
+        assertTrue(SUBNET_TABLE.get(CP1).contains(P1));
+        assertTrue(SUBNET_TABLE.get(CP2).contains(P1));
+    }
+
+    @Test
+    public void testOneSingleHomedToTwoSingleHomed() throws Exception {
+        processRouteAdded();
+
+        RouteEvent re = new RouteEvent(RouteEvent.Type.ALTERNATIVE_ROUTES_CHANGED, RR1, null,
+                Sets.newHashSet(RR1, RR2), Sets.newHashSet(RR1));
+        routeHandler.processAlternativeRoutesChanged(re);
+
+        assertEquals(2, ROUTING_TABLE.size());
+        MockRoutingTableValue rtv1 = ROUTING_TABLE.get(new MockRoutingTableKey(CP1.deviceId(), P1));
+        MockRoutingTableValue rtv2 = ROUTING_TABLE.get(new MockRoutingTableKey(CP2.deviceId(), P1));
+        assertEquals(M1, rtv1.macAddress);
+        assertEquals(M2, rtv2.macAddress);
+        assertEquals(V1, rtv1.vlanId);
+        assertEquals(V2, rtv2.vlanId);
+        assertEquals(CP1.port(), rtv1.portNumber);
+        assertEquals(CP2.port(), rtv2.portNumber);
+
+        assertEquals(2, SUBNET_TABLE.size());
+        assertTrue(SUBNET_TABLE.get(CP1).contains(P1));
+        assertTrue(SUBNET_TABLE.get(CP2).contains(P1));
+    }
+
+    @Test
+    public void testTwoSingleHomedToOneSingleHomed() throws Exception {
+        testTwoSingleHomedAdded();
+
+        RouteEvent re = new RouteEvent(RouteEvent.Type.ALTERNATIVE_ROUTES_CHANGED, RR1, null,
+                Sets.newHashSet(RR1), Sets.newHashSet(RR1, RR2));
+        routeHandler.processAlternativeRoutesChanged(re);
+
+        assertEquals(1, ROUTING_TABLE.size());
+        MockRoutingTableValue rtv1 = ROUTING_TABLE.get(new MockRoutingTableKey(CP1.deviceId(), P1));
+        assertEquals(M1, rtv1.macAddress);
+        assertEquals(V1, rtv1.vlanId);
+        assertEquals(CP1.port(), rtv1.portNumber);
+
+        assertEquals(1, SUBNET_TABLE.size());
+        assertTrue(SUBNET_TABLE.get(CP1).contains(P1));
+    }
+
+    @Test
+    public void testDualHomedSingleLocationFail() throws Exception {
+        testOneDualHomedAdded();
+
+        HostEvent he = new HostEvent(HostEvent.Type.HOST_MOVED, H3S, H3D);
+        routeHandler.processHostMovedEvent(he);
+
+        assertEquals(2, ROUTING_TABLE.size());
+        MockRoutingTableValue rtv1 = ROUTING_TABLE.get(new MockRoutingTableKey(CP1.deviceId(), P1));
+        MockRoutingTableValue rtv2 = ROUTING_TABLE.get(new MockRoutingTableKey(CP2.deviceId(), P1));
+        assertEquals(M3, rtv1.macAddress);
+        assertEquals(M3, rtv2.macAddress);
+        assertEquals(V3, rtv1.vlanId);
+        assertEquals(V3, rtv2.vlanId);
+        assertEquals(CP1.port(), rtv1.portNumber);
+        assertEquals(P9, rtv2.portNumber);
+
+        // ECMP route table hasn't changed
+        assertEquals(2, SUBNET_TABLE.size());
+        assertTrue(SUBNET_TABLE.get(CP1).contains(P1));
+        assertTrue(SUBNET_TABLE.get(CP2).contains(P1));
+    }
+
+    @Test
+    public void testDualHomedBothLocationFail() throws Exception {
+        testDualHomedSingleLocationFail();
+
+        hostService = new MockHostService(HOSTS_ONE_FAIL);
+
+        RouteEvent re = new RouteEvent(RouteEvent.Type.ROUTE_REMOVED, RR3, Sets.newHashSet(RR3));
+        routeHandler.processRouteRemoved(re);
+
+        assertEquals(0, ROUTING_TABLE.size());
+        assertEquals(0, SUBNET_TABLE.size());
+    }
+
+    @Test
+    public void testTwoSingleHomedRemoved() throws Exception {
+        testTwoSingleHomedAdded();
+
+        hostService = new MockHostService(HOSTS_BOTH_FAIL);
+
+        RouteEvent re = new RouteEvent(RouteEvent.Type.ROUTE_REMOVED, RR1, Sets.newHashSet(RR1, RR2));
+        routeHandler.processRouteRemoved(re);
+
+        assertEquals(0, ROUTING_TABLE.size());
+        assertEquals(0, SUBNET_TABLE.size());
+    }
+
+    @Test
+    public void testOneDualHomeRemoved() throws Exception {
+        testOneDualHomedAdded();
+
+        RouteEvent re = new RouteEvent(RouteEvent.Type.ROUTE_REMOVED, RR3, Sets.newHashSet(RR3));
         routeHandler.processRouteRemoved(re);
 
         assertEquals(0, ROUTING_TABLE.size());