Add Rules Iptables

https://www.e2enetworks.com/help/knowledge-base/how-to-open-ports-on-iptables-in-a-linux-server/#step-1-list-the-current-iptables-rules

https://kerneltalks.com/virtualization/how-to-reset-iptables-to-default-settings

https://upcloud.com/community/tutorials/configure-iptables-centos/

https://forums.centos.org/viewtopic.php?t=68917

https://www.thegeekstuff.com/2011/01/iptables-fundamentals/

 

 So, the structure is: 

 iptables -> Tables -> Chains -> Rules.

IPTABLES 

• Tables
• Chains
• Rules