title: Activating port forwarding disables local access
body: <p>I have a new internet service provider, and thus a new broadband router, a Sagemcom Fast 3890. I have some Raspberry Pis on the inside, that I need to open to the internet, so I've set up some port forwarding. However, when I activate port forwarding, local access is no longer possible.</p>
  
  <p>Example: I configure the Pi on 192.168.0.15 as a web server. I can access <a href="http://192.168.0.15/" rel="nofollow noreferrer">http://192.168.0.15/</a> and see the web page. When I activate port forwarding, I can now see the web page on my external IP address, but I no longer get a response from <a href="http://192.168.0.15/" rel="nofollow noreferrer">http://192.168.0.15/</a> - the request simply times out.</p>
  
  <p>This is a basic Raspbian install, nothing funny. Only thing is my broadband router is new. Is this a feature or a bug?</p>