Node Red Port

6 min read Oct 11, 2024

Understanding and Managing Node-RED Ports

Node-RED is a powerful tool for building visual workflows and automating tasks. One of the key aspects of setting up and running Node-RED is configuring the port it uses to communicate with other applications and devices. This article will guide you through the process of understanding and managing Node-RED ports, explaining how they function and addressing common issues you might encounter.

What is a Port and Why is it Important?

In the world of computer networking, a port is a virtual endpoint that allows communication between different applications or services running on a device. Each application uses a specific port number to differentiate itself from others. For example, the web server typically uses port 80, while email servers use port 25.

Node-RED, being a web-based application, also requires a port to operate. By default, it uses port 1880. This means that when you access Node-RED in your web browser, you will typically use the address http://localhost:1880.

Why You Might Need to Change the Node-RED Port

While the default port 1880 is generally suitable, there are several scenarios where you might need to change it:

Port Conflict: If another application is already using port 1880 on your computer, Node-RED will be unable to start. This is particularly common when running multiple Node-RED instances on the same machine.
Security: For security reasons, you might want to choose a non-standard port to make it harder for malicious actors to find and exploit your Node-RED instance.
Specific Requirements: Some deployments might require Node-RED to operate on a specific port for integration purposes.

How to Change the Node-RED Port

Changing the Node-RED port is a relatively simple process. Here's how you can do it:

Open the settings.js file: This file contains configuration settings for your Node-RED instance. It's located in the ~/.node-red directory on Linux and macOS, and in %USERPROFILE%\.node-red on Windows.
Find the uiPort property: This property defines the port Node-RED listens on for incoming connections.
Change the port number: Set uiPort to the desired port number, for example, uiPort: 8080.
Save the changes: Save the settings.js file and restart Node-RED.

After restarting, Node-RED will now be running on the new port you specified. You will need to update the URL you use to access it in your browser accordingly.

Troubleshooting Port Issues

If you encounter problems changing the Node-RED port, here are some common troubleshooting tips:

Check for existing processes: Use the netstat command (on Linux/macOS) or netstat (on Windows) to see if any other applications are already using the port you want to use.
Firewall settings: Make sure your firewall allows access to the new port.
System administrator rights: On some systems, you might need administrator privileges to modify port configurations.

Using Node-RED on Different Ports for Multiple Instances

If you need to run multiple Node-RED instances on the same machine, you can use different ports for each one. This allows you to isolate them and manage them independently.

Create separate Node-RED directories: Create different directories for each instance, for example, ~/node-red-instance1 and ~/node-red-instance2.
Configure separate settings.js files: Create settings.js files in each directory and set different uiPort values for each instance.
Start Node-RED instances: Start Node-RED in each directory using the appropriate command.

You can then access each instance using its respective port in your browser.

Conclusion

Understanding and managing Node-RED ports is an important aspect of using this powerful tool effectively. By choosing appropriate ports, you can ensure smooth operation, maintain security, and manage multiple instances without conflicts. If you encounter issues, remember to troubleshoot potential conflicts, firewall restrictions, and system administrator privileges.