title: Some cassandra nodes in cluster are unreachable even all the nodes are up and running
body: <p>I have cassandra cluster of 6 nodes on ec2 , Many times i have observed that all the nodes in the cluster are up and running but when i do the describe cluster from client it shows some nodes as unreachable.</p>
  
  <ol>
  <li><p>I can login to individual machines</p></li>
  <li><p>can connect to cassandra node with cassandra client</p></li>
  <li><p>can connect to individual nodes with JMX.</p></li>
  </ol>