title: hadoop port configuration within a firewall
body: <p>I have a customer where we have hadoop installation managed by us. In the current setup all the nodes in the cluster have all the ports open for each other. But the customer is quite reluctant to keep all the ports open. Can anyone let me know if any such configuration is at all possible where we instruct hadoop to use only restricted number of ports.</p>
  
  <p>My Findings : I have been able to configure a test setup where I have opened only the required port as per the mentioned blog 
  <a href="https://hadoop.apache.org/docs/r2.6.2/hadoop-project-dist/hadoop-hdfs/hdfs-default.xml" rel="nofollow">https://hadoop.apache.org/docs/r2.6.2/hadoop-project-dist/hadoop-hdfs/hdfs-default.xml</a></p>
  
  <p>But I still see the MR jobs are not executed in distributed manner.</p>