Open ports and save iptables rules

Viewing all iptables rules in Linux

iptables -S
iptables --list
iptables -L
iptables -S TABLE_NAME
iptables --table NameHere --list
iptables -t NameHere -L -n -v --line-numbers

Type the following command as root user:

iptables -L INPUT
iptables -L FORWARD
iptables -L OUTPUT
iptables -L

iptables -I INPUT -p tcp --dport xxxx -j ACCEPT
iptables -I INPUT -p udp --dport xxxx -j ACCEPT

ip6tables -I INPUT -p tcp --dport xxxx -j ACCEPT
ip6tables -I INPUT -p udp --dport xxxx -j ACCEPT

iptables -A OUTPUT -p tcp --dport xxxx -j ACCEPT
iptables -A OUTPUT -p udp --dport xxxx -j ACCEPT

ip6tables -I OUTPUT -p tcp --dport xxxx -j ACCEPT
ip6tables -I OUTPUT -p udp --dport xxxx -j ACCEPT

iptables -A INPUT  -p tcp -m multiport --dports 22,80,443 -j ACCEPT
iptables -A OUTPUT -p tcp -m multiport --sports 22,80,443 -j ACCEPT

iptables -A OUTPUT -p tcp -dport xxxx -j DROP

iptables-save -f /etc/iptables/iptables.rules

If you edit the iptables configuration file manually

iptables-restore /etc/iptables/iptables.rules

For more info, man iptables

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