title: Can't connect to cassandra - NoHostAvailableException
body: <p>I know there are several threads about the <code>NoHostAvailableException</code> but they simply don't provide a solution to my problem.</p>
  
  <p>I can't connect to Cassandra with the Datastax Java Cassandra Driver. I get the Error:</p>
  
  <blockquote>
    <p>com.datastax.driver.core.exceptions.NoHostAvailableException: All
    host(s) tried for query failed (tried: [/54.221.241.107])</p>
  </blockquote>
  
  <p>I am sure that the configuration is correct. I've set the configuration in cassandra.yaml:</p>
  
  <pre><code>start_native_transport: true 
  # port for the CQL native transport to listen for clients on 
  native_transport_port: 9042 
  </code></pre>
  
  <p>My Cassandra installation is a standard installation on a EC2 instance on AWS. I've configured AWS to allow port 9042.</p>
  
  <p>Cassandra is running on Windows Server 2008 R2 and I also configured the firewall to inbound and outbound connection on 9042.</p>
  
  <p>My code looks like the following:</p>
  
  <pre><code>cluster = Cluster.builder()
    .withPort(9042)
    .addContactPoint("54.221.241.107").build();
  </code></pre>
  
  <p>I don't know what to do anymore since I always get this error. Any suggestions?</p>