CORD-280 Added CLIs for cordvtn

Change-Id: I76e0358ccf3f71ad7cb1f9ba048616f0177d7666
diff --git a/apps/cordvtn/src/main/java/org/onosproject/cordvtn/OvsdbNode.java b/apps/cordvtn/src/main/java/org/onosproject/cordvtn/OvsdbNode.java
index c5b7a07..7a9a06a 100644
--- a/apps/cordvtn/src/main/java/org/onosproject/cordvtn/OvsdbNode.java
+++ b/apps/cordvtn/src/main/java/org/onosproject/cordvtn/OvsdbNode.java
@@ -19,11 +19,20 @@
 import org.onlab.packet.TpPort;
 import org.onosproject.net.DeviceId;
 
+import java.util.Comparator;
+
 /**
  * Representation of a node with ovsdb server.
  */
 public interface OvsdbNode {
 
+    Comparator<OvsdbNode> OVSDB_NODE_COMPARATOR = new Comparator<OvsdbNode>() {
+        @Override
+        public int compare(OvsdbNode ovsdb1, OvsdbNode ovsdb2) {
+            return ovsdb1.host().compareTo(ovsdb2.host());
+        }
+    };
+
     /**
      * Returns the IP address of the ovsdb server.
      *