hdfs - Getting the following error "Datanode denied communication with namenode" while configuring hadoop 0.23.8 -

I am trying to configure Hadoop 0.23.8 on my MacBook and am running with the following exceptions < / p>

  org.apache.hadoop.hdfs.server.protocol.DisallowedDatanodeException: org.apache.hadoop.hdfs.server.blockmanagement.DatanodeManager.registerDatanode (192.168.1.13:50010 on DatanodeManager.java: Datanode denied communication with namenode: 549) org.apache.hadoop.hdfs.server.namenode.FSNamesystem.registerDatanode (FSNamesystem.java:2548) on org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.registerDatanode (NameNodeRpcServer .java: 784) at sun.reflect.NativeMethodAccessorImpl.invoke0 (native resident method) sun.reflect.NativeMeth On odAccessorImpl.invoke (NativeMethodAccessorImpl.java:39) sun.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:25) on java.lang.reflect.Method.invoke on org.apache.hadoop.ipc.WritableRpcEngine $ Server.call ( WritableRpcEngine.java:394) to (Method.java:597) org.apache.hadoop.ipc on .Server $ handler $ 1.run org.apache.hadoop.ipc.Server $ handler at $ 1.run (Server.java : 1571) .security.auth.Subject.doAs on javax on java.security.AccessController.doPrivileged (Server.java:1567) (Native method) (Subject.java:396) org.apache.hadoop.ipc.Server $ on org.apache.hadoop.security.UserGroupInformation.doAs (UserGroupInformation.java:1262) on Handler.run (server .java: 1565)   
 My Core site.xml looks like this  
  & lt; Configuration & gt; & Lt; Property & gt; & Lt; Name & gt; Dfs.federation.nameservices & lt; / Name & gt; & Lt; Price & gt; Ns1 is also & lt; / Pricing & gt; & Lt; / Property & gt; & Lt; Property & gt; & Lt; Name & gt; Dfs.namenode.rpc-address.ns1 & lt; / Name & gt; & Lt; Price & gt; 192.168.1.13: 54,310 & lt; / Pricing & gt; & Lt; / Property & gt; & Lt; Property & gt; & Lt; Name & gt; Dfs.namenode.http-address.ns1 & lt; / Name & gt; & Lt; Price & gt; 192.168.1.13: 50070 & lt; / Pricing & gt; & Lt; / Property & gt; & Lt; Property & gt; & Lt; Name & gt; Dfs.namenode.secondary.http-address.ns1 & lt; / Name & gt; & Lt; Price & gt; 192.168.1.13: 50,090 & lt; / Pricing & gt; & Lt; / Property & gt; & Lt; / Configuration & gt;   
 Any ideas on what could be wrong?   
 
 
 It seems that I have a name resolution problem Possible reasons:  
  The machine file is listed in dfs.hosts.exclude defined by dfs.hosts is used and the machine is not listed within the file   
 Also ensure that in your host file The listed machine has an IP + hostname.  
 HH