title: Change ssl port of apache2 server. (ERR_SSL_PROTOCOL_ERROR)
body: <p>I'm developing apache2 environment on my EC2 instance. For security, I want to change ssl port of apache2.
  I've already confirmed default ssl port 443 was working by checking page with chrome browser. But after modifying ports.conf like below, I've got an error, <strong>ERR_SSL_PROTOCOL_ERROR</strong> when accessing this server like <a href="https://%3Cmy-ip%3E:18443/" rel="nofollow">https://xxxxxxx:18443/</a></p>
  
  <p>Are there any settings for changing ssl port?</p>
  
  <p><strong>listening ports</strong></p>
  
  <pre><code>$ ss -lnt
  State       Recv-Q Send-Q                         Local Address:Port                           Peer Address:Port
  LISTEN      0      128                                        *:22                                        *:*
  LISTEN      0      64                                         *:7777                                      *:*
  LISTEN      0      50                                 127.0.0.1:3306                                      *:*
  LISTEN      0      128                                       :::22                                       :::*
  LISTEN      0      128                                       :::18443                                    :::*
  </code></pre>
  
  <p><strong>/etc/apache2/ports.conf</strong></p>
  
  <pre><code>#Listen 80
  
  &lt;IfModule ssl_module&gt;
          Listen 18443
  &lt;/IfModule&gt;
  
  &lt;IfModule mod_gnutls.c&gt;
          Listen 18443
  &lt;/IfModule&gt;
  </code></pre>
  
  <p><strong>environment</strong></p>
  
  <ul>
  <li>OS: ubuntu 14.04 server (Amazon/EC2 AMI)</li>
  <li>apache: Apache/2.4.7 (Ubuntu)</li>
  </ul>
  
  <p><strong>EC2 inbound security policy</strong></p>
  
  <pre><code>Custom TCP rule: TCP, 18443, 0.0.0.0/0
  Custom UDP rule: UDP, 18443, 0.0.0.0/0
  </code></pre>