title: mongodb how to change default port
body: <p>For my project I need to use mongodb on port 80.
  In fact I can't use the default mongodb port (27017).
  I must use port 80.</p>
  
  <p>If I edit the config file:</p>
  
  <pre><code>sudo nano /etc/mongodb.conf
  </code></pre>
  
  <p>and I change the port to 80 then I restart mongodb service, I get this message when I try to connect to mongodb</p>
  
  <pre><code>$ mongo --port 80
  
  MongoDB shell version: 2.4.9
  connecting to: 127.0.0.1:80/test
  Fri Feb  6 14:16:42.705 Error: couldn't connect to server 127.0.0.1:80 at src/mongo/shell/mongo.js:147
  exception: connect failed
  </code></pre>
  
  <p>If I change the port again to 27017, all work fine.</p>
  
  <p>Can someone help me?</p>