iptables

Configure tables, chains and rules of the Linux kernel IPv4 firewall. Use ip6tables to set rules for IPv6 traffic. See also: iptables-save, iptables-restore. More information: https://manned.org/iptables.

sudo iptables --verbose --numeric --list --line-numbers

sudo iptables --policy chain rule

sudo iptables --append chain --source ip --jump rule

sudo iptables --append chain --source ip --protocol tcp|udp|icmp|... --dport port --jump rule

sudo iptables --table nat --append POSTROUTING --source 192.168.0.0/24 --jump MASQUERADE

sudo iptables --delete chain rule_line_number