Accessing Arduino Yun from Internet I am trying to access my Arduino Yun from the internet, and it's not quite working. I have correctly port forwarded the port 5555 from the router to the Yun (verified I am able to access my many other NAT'd resources). 

I can access the Yun from my internal network. 

In the Arduino sketch I have this (among many other things). Mainly taken from example sketches.

#include &lt;Bridge.h&gt;
#include &lt;HttpClient.h&gt;
#include &lt;YunServer.h&gt;
#include &lt;YunClient.h&gt;

YunServer server;

void setup {
   // Listen for incoming connections on port 5555
   server.noListenOnLocalhost();
   server.begin();
}


Is server.noListenOnLocalhost(); the right one to use to access from the outside world?
Well, I'm not familiar with the Yun, but the first thing that stands out is the missing

Bridge.begin();


line apparently needed to initialize the Bridge library that you use.

And you do have something like

YunClient client = server.accept();


and "more" in the main loop (or a function where applicable) of your code, right ?

And yes, noListenOnLocalhost() is the correct function for serving external clients.