I have manually installed CDH4 on a machine according to the default configurations given in the Cloudera installation documentation.   http://www.cloudera.com/content/cloudera-content/cloudera-docs/CDH4/4.2.1/CDH4-Installation-Guide/CDH4-Installation-Guide.html   I configured the machine to run in pseudo-distributed mode and the pseudo-cluster is working as expected when using the HDFS and MapReduce programs on the machine itself.   However, I have an application that is need of access to the NameNode port (8020). I am unable to make a connection to this port from an external machine despite having this port opened on the firewall. I found that the NameNode service is only listening on the localhost, thus rejecting requests from outside machines to communicate on this port.   $ sudo netstat -tulpn | grep :8020 tcp        0      0 127.0.0.1:8020              0.0.0.0:*                   LISTEN      16504/java   I want this service to listen to requests outside of the machine itself, just like I can communicate through port 50030 or 50070 on another machine. I have configured vi /etc/hadoop/conf.pseudo.mr1/core-site.xml to reference the machine name (hadoop) rather than localhost:   <property> <name>fs.default.name</name> <value>hdfs://hadoop:8020</value> </property> After restarting the NameNode service, I find that it is still only listening of 127.0.0.1. Is there any way to open to this port up for external usage? ... View more