[node.js] Node.js connect only works on localhost

I've written a small Node.js app, using connect, that serves up a web page, then sends it regular updates. It also accepts and logs user observations to a disk file.

It works fine as long as I am on localhost, but I can't get other computers on the same intranet to see it. I am using port 3000, but changing to port 8080 or 80 didn't help.

Here is the code I am using to set up the connection:

var io = require('socket.io'),
  connect = require('connect');

var app = connect().use(connect.static('public')).listen(3000);
var chat_room = io.listen(app);

As stated above, I've tried changing the port number to 8080 or to 80, and didn't see any difference, so I don't think that it is a firewall problem (but I could be wrong). I've also thought about, after reading similar questions dealing with HTTP, to add 0.0.0.0 to the listen() method but it doesn't seem that listen() takes an IP mask parameter.

Same problem here, for me solution was in editing server.js file line 161

 var server = app.listen(argv.port, '**<server.ip.adress.here>**', function() {
 console.log('Cesium development server running publicly.  Connect to localhost:%d/', server.address().port);
    });

replace localhost> with <server.ip.adress.here>

Binding to 0.0.0.0 is half the battle. There is an ip firewall (different from the one in system preferences) that blocks TCP ports. Hence port must be unblocked there as well by doing:

sudo ipfw add <PORT NUMBER> allow tcp from any to any

in my case I had to use both symbolic IP address "0.0.0.0" and call back while listen to server "cors": "^2.8.5", "express": "^4.17.1",

const cors = require("cors");
app.use(cors());

const port = process.env.PORT || 8000;
app.listen(port,"0.0.0.0" ,() => {
  console.log(`Server is running on port ${port}`);
});

you can also use, your local IP address instead of "0.0.0.0", In OS Ubuntu you can find your Ip address by using command

ifconfig | grep "inet " | grep -v 127.0.0.1

Then use the Ip Address:

app.listen(port,"192.168.0.131" ,() => {
  console.log(`Server is running on port ${port}`);
});

If you use fixed Ip address such as "192.168.0.131", then you must use it while calling to the server, such as, My api calling configuration for react client is bellow:

REACT_APP_API_URL = http://192.168.0.131:8001/api

On your app, makes it reachable from any device in the network:

app.listen(3000, "0.0.0.0");

For NodeJS in Azure, GCP & AWS

For Azure vm deployed in resource manager, check your virtual network security group and open ports or port ranges to make it reachable, otherwise in your cloud endpoints if vm is deployed in old version of azure.

Just look for equivalent of it for GCP and AWS

Working for me with this line (simply add --listen when running) :

node server.js -p 3000 -a : --listen 192.168.1.100

Hope it helps...

To gain access for other users to your local machine, i usually use ngrok. Ngrok exposes your localhost to the web, and has an NPM wrapper that is simple to install and start:

$ npm install ngrok -g
$ ngrok http 3000

See this example usage:

In the above example, the locally running instance of sails at: localhost:3000 is now available on the Internet served at: http://69f8f0ee.ngrok.io or https://69f8f0ee.ngrok.io

After struggling with this issue for quite some time I managed to solve it by allowing incoming connections on port 8080.

Since you wrote that the .listen(8080, "0.0.0.0") solution didn't work for you, make sure the connections on port 8080 are allowed through your firewall.

This post helped me to create a new Inbound rule in windows firewall settings.

I have a very simple solution for this problem: process.argv gives you a list of arguments passed to node app. So if you run:

node server.js 0.0.0.0

You'll get:

process.argv[0] //=> "node"
process.argv[1] //=> "server.js"
process.argv[2] //=> "0.0.0.0"

So you can use process.argv[2] to specify that as the IP address you want to listen to:

http.listen(3000, process.argv[2]);

Now, your app is listening to "all" IP addresses, for example http://192.168.1.4:3000/your_app.

I hope this will help someone!

Fedora or Centos distro check your selinux and firewalld in my case firewalld prevented the connection:

Selinux: $sestatus
SELinux status:                 enabled
SELinuxfs mount:                /sys/fs/selinux
SELinux root directory:         /etc/selinux
Loaded policy name:             targeted
Current mode:                   {{checkmode}}
Mode from config file:          {{checkconfig}}
Policy MLS status:              enabled
Policy deny_unknown status:     allowed
Max kernel policy version:      30

Firewalld status: $systemctl status firewalld

CHECK YOUR ANTI-VIRUS FIREWALL SETTINGS.

I have a NodeJS server working on Windows 10 PC, but when I put the IP address and port (example http://102.168.1.123:5000) into another computer's browser on my local network nothing happened, although it worked OK on the host computer.

(To find your windows IP address run CMD, then IPCONFIG)

Bar Horing Amir's answer points to the Windows firewall settings. On My PC the Windows Firewall was turned off - as McAfee anti-virus has added its own Firewall.

My system started to work on other computers after I added port 5000 to 'Ports and Systems Services' under the McAfee Firewall settings on the computer with NodeJS on it. Other anti-virus software will have similar settings.

I would seriously suggest trying this solution first with Windows.