title: Protocol error when executing cpp-driver datastax
body: <p>I am currently workinig on datastax cpp-driver in C and was working around some examples when I came across a very trivial problem. While trying to execute the <a href="https://github.com/datastax/cpp-driver/blob/master/examples/auth/auth.c" rel="nofollow noreferrer">Basic Authentication Script</a> here, I found this error showing up and the code execution getting stuck.</p>
  
  <p><strong>The Error:</strong></p>
  
  <pre><code>1587040775.210 [ERROR] (cluster_connector.cpp:192:void datastax::internal::core::ClusterConnector::on_connect(datastax::internal::core::ControlConnector*)): Unable to establish a control connection to host 127.0.0.3 because of the following error: Underlying connection error: Connect error 'connection refused'
  1587040775.210 [ERROR] (cluster_connector.cpp:192:void datastax::internal::core::ClusterConnector::on_connect(datastax::internal::core::ControlConnector*)): Unable to establish a control connection to host 127.0.0.2 because of the following error: Underlying connection error: Connect error 'connection refused'
  1587040775.211 [ERROR] (cluster_connector.cpp:192:void datastax::internal::core::ClusterConnector::on_connect(datastax::internal::core::ControlConnector*)): Unable to establish a control connection to host 127.0.0.1 because of the following error: Underlying connection error: Received error response 'Invalid or unsupported protocol version (66); supported versions are (3/v3, 4/v4, 5/v5-beta)' (0x0200000A)
  1587040775.211 [WARN] (cluster_connector.cpp:289:void datastax::internal::core::ClusterConnector::on_connect(datastax::internal::core::ControlConnector*)): Host 127.0.0.1 does not support protocol version DSEv2. Trying protocol version DSEv1...
  1587040775.212 [ERROR] (cluster_connector.cpp:192:void datastax::internal::core::ClusterConnector::on_connect(datastax::internal::core::ControlConnector*)): Unable to establish a control connection to host 127.0.0.1 because of the following error: Underlying connection error: Received error response 'Invalid or unsupported protocol version (65); supported versions are (3/v3, 4/v4, 5/v5-beta)' (0x0200000A)
  1587040775.212 [WARN] (cluster_connector.cpp:289:void datastax::internal::core::ClusterConnector::on_connect(datastax::internal::core::ControlConnector*)): Host 127.0.0.1 does not support protocol version DSEv1. Trying protocol version v4...
  </code></pre>
  
  <p>What could be these protocols that are not supported by my machine? Also, after it comes to the last warning, which is <code>trying protocol v4</code> it gets stuck.
  I'm using Casssandra 3.10+, Cpp-driver 2.13.</p>
  
  <p>Anybody with a workaround or a solution would be of much help. Thanks in advance</p>