Why is Django throwing error "DisallowedHost at /"?
<p>I am setting up my own Django server using this <a href="https://www.digitalocean.com/community/tutorials/how-to-set-up-django-with-postgres-nginx-and-gunicorn-on-ubuntu-14-04" rel="noreferrer">Digital Ocean tutorial</a>. I created the Django framework following each step, and ran the server using this command:</p>

<pre><code>./manage.py runserver 0.0.0.0:8000
</code></pre>

<p>When I tried to visit the IP at port 8000, the following error was shown:</p>

<pre><code>DisallowedHost at /
Invalid HTTP_HOST header: 'XXX.XXX.XXX.XXX:8000'. You may need to add u'XXX.XXX.XXX.XXX' to ALLOWED_HOSTS.
</code></pre>

<p>(IP substituted with X's)</p>

<p>Why is this happening?</p>