title: Cannot connect to remote computer when using PuTTY ssh
body: <p>I have a remote server with Ubuntu 12.04 installed.<br>
  I want to use PuTTY to establish connection, but I get a fatal error.<br>
  The information is show as below:</p>
  
  <pre><code>Couldn't agree a host key algorithm (available ecdsa-sha2-nistp256)
  </code></pre>
  
  <p>I have searched the solution by Google but failed. I just want to know how to solve it.</p>