listen EADDRNOTAVAIL error in Node.js

I had this issue, and I thought it was a port issue, but it turned out to be an IP issue.

I had my HOST environmental variable pointing to a static IP, and my Node server was listening to that address. At some point when my router recycled, it started assigning my machine a new IP, and I started getting the error you posted. It was fixed by changing the address my server was listening to.

My config:

app.set('port', process.env.PORT || 3000);
app.set('host', process.env.HOST || '0.0.0.0');

http.createServer(app).listen(app.get('port'), app.get('host'), function(){
  console.log("Express server listening on port " + app.get('port'));
});

Make sure your host is hitting your machine. In any case, the loopback, as @miltonb suggested, should always work:

app.set('host', '127.0.0.1');

Could it be that node was already running a server? I received a similar error and found this while troubleshooting. Shutting down the previous node server solved my problem.

I think you need a bit more context like some of your code. I am guessing you are starting to listen on a web server or a socket? Based on that assumption, I get something similar when I run a basic web server on my test server unless I run using localhost.

events.js:48
        throw arguments[1]; // Unhandled 'error' event
                   ^
Error: listen EADDRNOTAVAIL
    at errnoException (net.js:670:11)
    at Array.0 (net.js:756:28)
    at EventEmitter._tickCallback (node.js:190:38)

Try changing the [hostname] parameter to localhost:

var http = require('http');
http.createServer( function ).listen(8000, '127.0.0.1');

I was getting the same error, and then I changed the port and worked

Most of the time it would be the IP address or the hostname. The reason being, node js takes that as the key item to start the server. if there is a conflict or incorrect ip address, it cribs with this error

Error: listen EADDRNOTAVAIL

hope this helps.