Iptables

Show ip rules

sudo iptables -L --line-numbers
# shows port numbers instead of text
sudo iptables -L --line-numbers -n

Delete Rule

# delete rule
sudo iptables -D INPUT 6

Add Rule

sudo iptables -A INPUT -p tcp --dport 80 -j ACCEPT

Delete ALL rules (VERY UNSAFE, BACKUP FIRST)

# F for flush I assume
iptables -F

Restore iptables config (after saving using iptables-save)

sudo iptables-restore < /etc/iptables.rules

Permanently enable iptables rrules

sudo yum install iptables-services -y
# restore/change iptables (make sure it works and can ssh)

sudo systemctl start iptables
sudo systemctl enable iptables
sudo systemctl status iptables

sudo systemctl disable firewalld.service
sudo systemctl stop firewalld.service

Login to root then:

iptables-save >/etc/sysconfig/iptables