Ambari to install Kafka on AWS EC2

Using Ambari 2.1 to install Kafka(HDP 2.3) only on an AWS EC2 instance was successful. But the Tutorial, http://hortonworks.com/hadoop-tutorial/simulating-transporting-realtime-events-stream-apache-kafka/, was failed due to a connection issue to the broker. I was running the code on the same computer that runs Kafka server, like this: # java -cp /opt/Tutorial-1.0-SNAPSHOT.jar com.hortonworks.tutorials.tutorial1.TruckEventsProducer localhost:6667 localhost:2181