Link added event is needed as part of topology update
diff --git a/src/main/java/net/floodlightcontroller/linkdiscovery/ILinkDiscovery.java b/src/main/java/net/floodlightcontroller/linkdiscovery/ILinkDiscovery.java
index 1efe015..1df7eb5 100644
--- a/src/main/java/net/floodlightcontroller/linkdiscovery/ILinkDiscovery.java
+++ b/src/main/java/net/floodlightcontroller/linkdiscovery/ILinkDiscovery.java
@@ -8,6 +8,7 @@
 
     @JsonSerialize(using=ToStringSerializer.class)
     public enum UpdateOperation {
+    	LINK_ADDED("Link Added"),
         LINK_UPDATED("Link Updated"),
         LINK_REMOVED("Link Removed"),
         SWITCH_UPDATED("Switch Updated"),