diff --git a/apps/openstacknetworking/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackPurgeRulesCommand.java b/apps/openstacknetworking/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackPurgeRulesCommand.java
new file mode 100644
index 0000000..c6adee2
--- /dev/null
+++ b/apps/openstacknetworking/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackPurgeRulesCommand.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2017-present Open Networking Laboratory
+ *
+ * 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.onosproject.openstacknetworking.cli;
+
+import org.apache.karaf.shell.commands.Command;
+import org.onosproject.cli.AbstractShellCommand;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
+import org.onosproject.net.flow.FlowRuleService;
+import org.onosproject.openstacknetworking.api.Constants;
+
+/**
+ * Purges all existing network states.
+ */
+@Command(scope = "onos", name = "openstack-purge-rules",
+        description = "Purges all flow rules installed by OpenStack networking app")
+public class OpenstackPurgeRulesCommand extends AbstractShellCommand {
+
+    @Override
+    protected void execute() {
+        FlowRuleService flowRuleService = AbstractShellCommand.get(FlowRuleService.class);
+        CoreService coreService = AbstractShellCommand.get(CoreService.class);
+        ApplicationId appId = coreService.getAppId(Constants.OPENSTACK_NETWORKING_APP_ID);
+        if (appId == null) {
+            error("Failed to purge OpenStack networking flow rules.");
+            return;
+        }
+        flowRuleService.removeFlowRulesById(appId);
+        print("Successfully purged flow rules installed by OpenStack networking application.");
+    }
+}
diff --git a/apps/openstacknetworking/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackSyncRulesCommand.java b/apps/openstacknetworking/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackSyncRulesCommand.java
new file mode 100644
index 0000000..30b040c
--- /dev/null
+++ b/apps/openstacknetworking/src/main/java/org/onosproject/openstacknetworking/cli/OpenstackSyncRulesCommand.java
@@ -0,0 +1,41 @@
+/*
+ * Copyright 2017-present Open Networking Laboratory
+ *
+ * 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.onosproject.openstacknetworking.cli;
+
+import org.apache.karaf.shell.commands.Command;
+import org.onosproject.cli.AbstractShellCommand;
+import org.onosproject.openstacknode.OpenstackNodeService;
+
+/**
+ * Re-installs flow rules for OpenStack networking.
+ */
+@Command(scope = "onos", name = "openstack-sync-rules",
+        description = "Re-installs flow rules for OpenStack networking")
+public class OpenstackSyncRulesCommand extends AbstractShellCommand {
+
+    @Override
+    protected void execute() {
+        // All handlers in this application reacts the node complete event and
+        // tries to re-configure flow rules for the complete node.
+        OpenstackNodeService nodeService = AbstractShellCommand.get(OpenstackNodeService.class);
+        if (nodeService == null) {
+            error("Failed to re-install flow rules for OpenStack networking.");
+            return;
+        }
+        nodeService.completeNodes().forEach(nodeService::processCompleteState);
+        print("Successfully requested re-installing flow rules.");
+    }
+}
diff --git a/apps/openstacknetworking/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingHandler.java b/apps/openstacknetworking/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingHandler.java
index 4cace0f..c5d5f29 100644
--- a/apps/openstacknetworking/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingHandler.java
+++ b/apps/openstacknetworking/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingHandler.java
@@ -516,7 +516,7 @@
                 case COMPLETE:
                 case INCOMPLETE:
                     eventExecutor.execute(() -> {
-                        log.info("COMPLETE node {} detected", osNode.hostname());
+                        log.info("Reconfigure routers for {}", osNode.hostname());
                         reconfigureRouters();
                     });
                     break;
diff --git a/apps/openstacknetworking/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingSnatHandler.java b/apps/openstacknetworking/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingSnatHandler.java
index eb08cc3..bd6eeb2 100644
--- a/apps/openstacknetworking/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingSnatHandler.java
+++ b/apps/openstacknetworking/src/main/java/org/onosproject/openstacknetworking/impl/OpenstackRoutingSnatHandler.java
@@ -24,7 +24,6 @@
 import org.onlab.packet.IPv4;
 import org.onlab.packet.IpAddress;
 import org.onlab.packet.IpPrefix;
-import org.onlab.packet.MacAddress;
 import org.onlab.packet.TCP;
 import org.onlab.packet.TpPort;
 import org.onlab.packet.UDP;
@@ -149,8 +148,8 @@
 
     private void initializeUnusedPortNumSet() {
         for (int i = TP_PORT_MINIMUM_NUM; i < TP_PORT_MAXIMUM_NUM; i++) {
-            if (!allocatedPortNumMap.containsKey(Integer.valueOf(i))) {
-                unUsedPortNumSet.add(Integer.valueOf(i));
+            if (!allocatedPortNumMap.containsKey(i)) {
+                unUsedPortNumSet.add(i);
             }
         }
 
@@ -168,26 +167,25 @@
         IPv4 iPacket = (IPv4) eth.getPayload();
         InboundPacket packetIn = context.inPacket();
 
-        int patPort = getPortNum(eth.getSourceMAC(),
-                iPacket.getDestinationAddress());
+        int patPort = getPortNum();
+        if (patPort == 0) {
+            log.error("There's no unused port for PAT. Drop this packet");
+            return;
+        }
 
         InstancePort srcInstPort = instancePortService.instancePort(eth.getSourceMAC());
         if (srcInstPort == null) {
-            log.trace(ERR_PACKETIN + "source host(MAC:{}) does not exist",
+            log.error(ERR_PACKETIN + "source host(MAC:{}) does not exist",
                     eth.getSourceMAC());
             return;
         }
+
         IpAddress srcIp = IpAddress.valueOf(iPacket.getSourceAddress());
         Subnet srcSubnet = getSourceSubnet(srcInstPort, srcIp);
         IpAddress externalGatewayIp = getExternalIp(srcSubnet);
         if (externalGatewayIp == null) {
             return;
         }
-        if (patPort == 0) {
-            log.error("There's no unused port for external ip {}... Drop this packet",
-                    getExternalIp(srcSubnet));
-            return;
-        }
 
         populateSnatFlowRules(context.inPacket(),
                 srcInstPort,
@@ -420,29 +418,27 @@
                 ByteBuffer.wrap(ethPacketIn.serialize())));
     }
 
-    private int getPortNum(MacAddress sourceMac, int destinationAddress) {
+    private int getPortNum() {
         if (unUsedPortNumSet.isEmpty()) {
             clearPortNumMap();
         }
 
         int portNum = findUnusedPortNum();
-
         if (portNum != 0) {
-            unUsedPortNumSet.remove(Integer.valueOf(portNum));
-            allocatedPortNumMap
-                    .put(Integer.valueOf(portNum), Long.valueOf(System.currentTimeMillis()));
+            unUsedPortNumSet.remove(portNum);
+            allocatedPortNumMap.put(portNum, System.currentTimeMillis());
         }
 
         return portNum;
     }
 
     private int findUnusedPortNum() {
-        return unUsedPortNumSet.stream().findAny().orElse(Integer.valueOf(0)).intValue();
+        return unUsedPortNumSet.stream().findAny().orElse(0);
     }
 
     private void clearPortNumMap() {
         allocatedPortNumMap.entrySet().forEach(e -> {
-            if (System.currentTimeMillis() - e.getValue().value().longValue() > TIME_OUT_SNAT_PORT_MS) {
+            if (System.currentTimeMillis() - e.getValue().value() > TIME_OUT_SNAT_PORT_MS) {
                 allocatedPortNumMap.remove(e.getKey());
                 unUsedPortNumSet.add(e.getKey());
             }
diff --git a/apps/openstacknetworking/src/main/resources/OSGI-INF/blueprint/shell-config.xml b/apps/openstacknetworking/src/main/resources/OSGI-INF/blueprint/shell-config.xml
index 67ab56a..8e6cda7 100644
--- a/apps/openstacknetworking/src/main/resources/OSGI-INF/blueprint/shell-config.xml
+++ b/apps/openstacknetworking/src/main/resources/OSGI-INF/blueprint/shell-config.xml
@@ -36,5 +36,11 @@
         <command>
             <action class="org.onosproject.openstacknetworking.cli.OpenstackSecurityGroupListCommand"/>
         </command>
+        <command>
+            <action class="org.onosproject.openstacknetworking.cli.OpenstackPurgeRulesCommand"/>
+        </command>
+        <command>
+            <action class="org.onosproject.openstacknetworking.cli.OpenstackSyncRulesCommand"/>
+        </command>
     </command-bundle>
 </blueprint>