-if any. Processing the current set of actions then stops.
-However, if the current set of actions was reached through
-``resubmit'' then remaining actions in outer levels resume
-processing.
+if any. Processing the current set of actions then stops. However,
+if the current set of actions was reached through ``resubmit'' then
+remaining actions in outer levels resume processing. This action
+also optionally supports the ability to specify a list of valid
+controller ids. Each of controllers in the list will receive the
+``packet_in'' message only if they have registered to receive the
+invalid ttl packets. If controller ids are not specified, the
+``packet_in'' message will be sent only to the controllers having
+controller id zero which have registered for the invalid ttl packets.