title: How can I find out the reason of 'request timed out' on AWS?
body: <p>I can't access my website suddenly hosted on AWS EC2. <code>ping example.com</code> gets the following result:</p>
  <pre><code>PING example.com
  
  Pinging example.com [xx.xx.xx.xx] with 32 bytes of data:
  Request timed out.
  Request timed out.
  Request timed out.
  Request timed out.
  </code></pre>
  <p>PS: the security group associated with my instance is as follows:</p>
  <pre><code>Ports   Protocol    Source  launch-wizard-2
  22  tcp 0.0.0.0/0   ✔
  80  tcp 0.0.0.0/0   ✔
  443 tcp 0.0.0.0/0   ✔
  </code></pre>
  <p>I can't connect to my instance using ssh as well (can't access log file). All what I can do is to check the EC2 dashboard <code>aws.amazon.com</code>. Everything looks fine.</p>
  <p>In <code>Status Checks</code>,</p>
  <blockquote>
  <p>System Status Checks  System reachability check passed Instance</p>
  <p>Status Checks  Instance reachability check passed</p>
  </blockquote>
  <p>Here is a screenshot.</p>
  <p><img src="https://i.stack.imgur.com/2LNIR.png" alt="enter image description here" /></p>
  <p><strong>How can I find out the reason?</strong></p>
  <p>PS: the last backup file downloaded to dropbox is <code>backwpup_b9aba0_2015-07-12_03-03-25.tar.gz</code>.</p>
  <hr />
  <p><strong>EDITT</strong>: Now it works. I guess that the issue is caused by the limitation of CPU credits (<code>t2.micro</code>) but I am not sure.</p>
  <p><img src="https://i.stack.imgur.com/sGwfi.png" alt="enter image description here" /></p>