How to open ports in firewalld

In this guide, you’ll learn how to open a port in firewalld, either by specifying a port number or enabling a premade service. Then you’ll be able to to verify which ports and services are currently active, ensuring your configuration is correct.

Opening a port in firewalld is a common first step after installation as it crucial in securing your VPS and any applications you run, helping to prevent unauthorised access. If you prefer you can learn how to use UFW or uncomplicated firewall instead.

Open a Port in Firewalld

Access Your Server via SSH

Begin by logging into your Linux server using SSH with sufficient privileges:

user@your-server-ip

Check If the Port Has a Named Service

Before adding a port manually, it’s best to see if firewalld already recognises the port as a named service. This makes configuration more readable and easier to manage:

firewall-cmd --get-services

Look for a service name that corresponds to your application.

Open a service permanently

Enable it using this command:

sudo firewall-cmd --permanent --add-service=SERVICE

Replace service with the appropriate name for example: httpd, mysql.

Open a port permanently

Manually open the port by specifying the port number and protocol:

sudo firewall-cmd --permanent --add-port=3080/tcp

Replace 3080 and tcp with the port you need opened and the protocol its on.

Reload firewalld to apply changes

To make your changes active, reload the Firewalld configuration:

sudo firewall-cmd --reload

This applies all permanent changes and resets any temporary runtime rules.

Check those ports are opened

After updating your firewall, it’s essential to confirm the correct services and ports are enabled.

List Active Services

sudo firewall-cmd --list-services

List Open Ports

sudo firewall-cmd --list-ports