Linux firewalld Commands

1. View firewalld Rules

sudo firewall-cmd --list-all

2. Add and Remove Port Access for All IPs

• Add Port Access

sudo firewall-cmd --permanent --zone=public --add-port=22/tcp

• Remove Port Access

sudo firewall-cmd --permanent --zone=public --remove-port=22/tcp

3. Add Rules for Allowing IP Whitelisting in firewalld

After starting the firewalld service, all services are denied by default, and relevant IP whitelisting must be enabled for access

• Add Rich Rule for Single IP Whitelisting

sudo firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="192.168.1.100" port port="22" protocol="tcp" accept'

• Add Rich Rule for Subnet Whitelisting

sudo firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="192.168.1.0/24" port port="22" protocol="tcp" accept'

• Remove Whitelist from Rich Rule

sudo firewall-cmd --permanent --remove-rich-rule='rule family="ipv4" source address="192.168.1.100" port port="22" protocol="tcp" accept'

• Save Rules After Adding

sudo firewall-cmd --reload