https://interface31.livejournal.com/83089.html
https://interface31.ru/tech_it/2020/02/osnovy-iptables-dlya-nachinayushhih-chast-1.html
https://timeweb.cloud/tutorials/centos/kak-nastroit-iptables-na-centos
Stop ipfilters
https://serverfault.com/questions/129086/how-to-start-stop-iptables-on-ubuntu
https://www.cyberciti.biz/faq/ubuntu-server-disable-firewall/
Finally, type the following commands to stop firewall and flush all the rules:$ sudo iptables -X
$ sudo iptables -t nat -F
$ sudo iptables -t nat -X
$ sudo iptables -t mangle -F
$ sudo iptables -t mangle -X
$ sudo iptables -P INPUT ACCEPT
$ sudo iptables -P FORWARD ACCEPT
$ sudo iptables -P OUTPUT ACCEPT
