diff --git a/src/main/java/net/floodlightcontroller/core/internal/SwitchStorageImpl.java b/src/main/java/net/floodlightcontroller/core/internal/SwitchStorageImpl.java
index a068586..17ab274 100644
--- a/src/main/java/net/floodlightcontroller/core/internal/SwitchStorageImpl.java
+++ b/src/main/java/net/floodlightcontroller/core/internal/SwitchStorageImpl.java
@@ -6,6 +6,7 @@
 import net.floodlightcontroller.core.INetMapTopologyObjects.ISwitchObject;
 import net.floodlightcontroller.core.ISwitchStorage;
 import net.onrc.onos.util.GraphDBConnection;
+import net.onrc.onos.util.GraphDBConnection.GenerateEvent;
 import net.onrc.onos.util.GraphDBConnection.Transaction;
 
 import org.openflow.protocol.OFPhysicalPort;
@@ -15,7 +16,7 @@
 import org.slf4j.LoggerFactory;
 
 public class SwitchStorageImpl implements ISwitchStorage {
-	public GraphDBConnection conn;
+	protected GraphDBConnection conn;
 	protected static Logger log = LoggerFactory.getLogger(SwitchStorageImpl.class);
 
 	@Override
@@ -177,11 +178,12 @@
             		log.info("SwitchStorage:deletePort dpid:{} port:{} found and deleted", dpid, port);
             		sw.removePort(p);
             		conn.utils().removePort(conn, p);
-            		conn.endTx(Transaction.COMMIT);
+            		conn.endTx(Transaction.COMMIT,GenerateEvent.TRUE);
             	}
             }
 		} catch (Exception e) {
              // TODO: handle exceptions
+			e.printStackTrace();
 			conn.endTx(Transaction.ROLLBACK);
 			log.info("SwitchStorage:deletePort dpid:{} port:{} failed", dpid, port);
 		}