Cannot access Google Cloud Compute Instance External IP
<p>I have set up an Google Cloud Compute Instance:</p>

<ul>
<li>Machine type

<ul>
<li>n1-standard-1 (1 vCPU, 3.75 GB memory)</li>
</ul></li>
<li>CPU platform

<ul>
<li>Intel Haswell</li>
</ul></li>
<li>Zone

<ul>
<li>us-east1-c</li>
</ul></li>
</ul>

<p>I can ssh in using the external address.  </p>

<p>I have installed the <code>vncserver</code> and can access it on port 5901 from localhost as well as the internal IP.</p>

<p>I am trying to access it from the static, external IP address but it is not working. </p>

<p>I have configured the firewall to open to port to <strong>0.0.0.0/0</strong>, but it is not reachable.</p>

<p>Can anyone help?</p>

<p>------after further investigation from the tips from the two answers (thanks, both!), I have a partial answer:</p>

<blockquote>
  <p>The Google Cloud Compute instance was set, by default, to not allow
  HTTP traffic.  I reset the configuration to allow HTTP traffic.  I
  then tried the troubleshooting tip to run a small HTTP service in
  python.  I was able to get a ressponse from the service over the
  internet.</p>
</blockquote>

<p>The summary of the current situation is as follows:</p>

<ul>
<li>The external IP address can be reached</li>
<li>It is enabled and working for SSH</li>
<li>It is enabled and working for HTTP</li>
<li>It does not seem to allow traffic from <code>vncserver</code></li>
</ul>

<p>Any idea how to configure the compute instance to allow for <code>vncserver</code> traffic?</p>