Fixed an issue with leaking LLDPs across islands in TopologyImpl.

src/main/java/net/floodlightcontroller/topology/internal/TopologyImpl.java

@@ -574,7 +574,10 @@ public class TopologyImpl implements IOFMessageListener, IOFSwitchListener,
         if (remoteSwitch == null) {
             // Ignore LLDPs not generated by Floodlight, or from a switch that has recently
             // disconnected, or from a switch connected to another Floodlight instance
-            return Command.CONTINUE;
+            if (log.isDebugEnabled()) {
+                log.debug("Received LLDP from remote switch not connected to the controller");
+            }
+            return Command.STOP;
         }
         
         if (!remoteSwitch.portEnabled(remotePort)) {
@@ -601,7 +604,7 @@ public class TopologyImpl implements IOFMessageListener, IOFSwitchListener,
     }
     
     private Command handleBpdu(BPDU bpdu, IOFSwitch sw, OFPacketIn pi) {
-        // TODO - fill this in.
+        // TODO - handle STP here
         return Command.STOP;
     }
     
@@ -620,7 +623,6 @@ public class TopologyImpl implements IOFMessageListener, IOFSwitchListener,
         return Command.CONTINUE;
     }
 
-    //TODO - we can optimize the updating clusters on a link added
     protected void addOrUpdateLink(LinkTuple lt, int srcPortState, 
                                                             int dstPortState) {
         lock.writeLock().lock();
@@ -663,9 +665,6 @@ public class TopologyImpl implements IOFMessageListener, IOFSwitchListener,
                 updateOperation = UpdateOperation.ADD;
                 linkChanged = true;
 
-                if (log.isTraceEnabled()) {
-                    log.trace("Added link {}", lt);
-                }
                 log.info("Added link {}", lt);
             } else {
                 // Only update the port states if they've changed