List rules with line numbers iptables
Show INPUT chain rules with packet/byte counters
iptables -L INPUT --line-numbers -n -v
more iptables
all 10 commands →
Allow incoming port
iptables -A INPUT -p tcp --dport 443 -j ACCEPT
Block IP address
iptables -I INPUT 1 -s 203.0.113.5 -j DROP
NAT: masquerade outbound
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
Save and restore rules
iptables-save > /etc/iptables/rules.v4
iptables-restore < /etc/iptables/rules.v4
Delete a rule by number
iptables -D INPUT 3