iptables and ufw (uncomplicated firewall)

iptables

iptables

ufw

ufw

ufw built on iptables

deny on port
deny on ip

using iptabes/ufw to block ports ufw status

ufw allow in on cni0 && sudo ufw allow out on cni0
ufw default allow routed
ufw allow 6443/tcp
ufw allow 443/tcp

Firewalling a network

Networks and router firewalls