Firewalld is a firewall management solution used by the most of modern Linux distributions. In this tutorial you will learn how to open ports in firewalld. This tutorial describe you to open a port for public, specific IP or IP range in firewalld. Find our previous article about installation and uses of Firewalld on Linux system.
In this tutorial, all the commands are written for MySQL port 3306. You can use the same command for any other ports as per your requirements.
Allow Port for All Traffic
Use the following commands to allow incoming traffic on port 3306 to all traffic coming from public network.
firewall-cmd --zone=public --add-port=3306/tcp
To add rule for permanent use
--permanent option with command.
firewall-cmd --permanent --zone=public --add-port=3306/tcp
Allow Port for Specific IP
You can also restrict access on any port based on source address. To open port access based on source address needed to add firewall rich rule.
Run the below command to allow access for port 4567 to 192.168.0.0/24 network.
firewall-cmd --permanent --zone=public --add-rich-rule=' rule family="ipv4" source address="192.168.0.0/24" port protocol="tcp" port="3306" accept'
Reload the firewall rules to apply changes.
After adding the rules in firewalld, You can verify the by the running following command.
public (active) target: default icmp-block-inversion: no interfaces: eth0 sources: services: cockpit dhcpv6-client ssh ports: protocols: masquerade: no forward-ports: source-ports: icmp-blocks: rich rules: rule family="ipv4" source address="192.168.0.0/24" port port="3306" protocol="tcp" accept
The last line of output shows the rich rules added the firewalld.
Remove Rules from Firewalld
If you don’t need to keep the ports open, you can remove/deny the above ports from the firewalld using the –remove-port option:
firewall-cmd --permanent --zone=public --remove-port=3306/tcp
Next, run the following command to apply the changes:
In this tutorial, you have learned to open port access to all traffic or specific IP address/network using firewalld on Linux operating systems.