How to Add a Port in Firewall Configuration on CentOS 8 (firewall-cmd)

Firewall is a network security tool that provide network level security based on a set of rules. It has controls on incoming and outgoing traffic.

This article describes How to Add a Port in Firewall Configuration on CentOS 8 (firewall-cmd).

 

[root@linuxcnf ~]# cat /etc/redhat-release CentOS Linux release 8.5.2111 [root@linuxcnf ~]#

 

Step 1. Check the Service Status: Run the following command to check firewall running status:

 

[root@linuxcnf ~]# firewall-cmd --stat running [root@linuxcnf ~]#

 

[root@linuxcnf ~]# firewall-cmd --list-ports   [root@linuxcnf ~]#

 

Step 2. Adding Port: Run the following command to allow port in firewall:

 

[root@linuxcnf ~]# firewall-cmd --permanent --zone=public --add-port=80/tcp success [root@linuxcnf ~]#

 

Change the port and protocol (tcp/udp) as desire.

 

Step 3. Reloading the Service: Run the following command for soft reloading firewall service to reflect the changes:

 

[root@linuxcnf ~]# firewall-cmd --reload success [root@linuxcnf ~]#

 

Step 4. Validate the Configuration: Run the following command to verify the configuration:

 

root@linuxcnf ~]# firewall-cmd --list-ports 80/tcp [root@linuxcnf ~]#

 

Done!!! Port 80 is successfully allowed from Linux Firewall on CentOS 8.