How to use Firewalld service to enable/disable port in Linux machine
Firewalld is Linux firewall management tool with support for IPv4, IPv6, Ethernet bridges and IPSet firewall settings.
It acts as a front-end to Linux kernel’s netfilter framework.
Firewalld is a default firewall management software on RHEL 7 family.
How to install firewalld
Ubuntu
sudo apt install firewalld -y
Check the status of firewalld service
sudo systemctl status firewalld
To list all firewall rules configured
firewall-cmd --list-all
By default all ports are blocked when firewall is enabled except ssh and dhcpv6-client services.
To enable TCP port
Lets enable port 8080
sudo firewall-cmd --add-port=8080/tcp --permanent
sudo firewall-cmd --reload
sudo firewall-cmd --list-all
Get a list of all services that can be enabled using a service name
sudo firewall-cmd --get-services
Enable service port using service name
Lets enable Enable http service
sudo firewall-cmd --add-service=http --permanent
sudo firewall-cmd --reload
sudo firewall-cmd --list-all
To disable enabled TCP port
Lets disable port 8080
sudo firewall-cmd --remove-port=8080/tcp --permanent
sudo firewall-cmd --reload
sudo firewall-cmd --list-all
To uninstall firewalld
sudo apt autoremove firewalld -y
Reference
- https://computingforgeeks.com/install-and-use-firewalld-on-ubuntu-18-04-ubuntu-16-04/