Iptables Essentials: Common Firewall Rules and Commands | DigitalOcean
Iptables is the software firewall that is included with most Linux distributions by default. This cheat sheet-style guide provides a quick reference to iptables commands that will create firewall rules are useful in common, everyday scenarios. This in
This is an incredibly useful reference for admins who deal with some other than usual ALLOW ANY ANY cases that most of us might have to deal with in our complex production and lab environments.
The man pages and IPtables home pages are obviously the most verbose and granular use case when it comes to admin reference. They built this stuff so obviously they know best. However most admins are only looking to solve one or two problems at a time. Quite often they know exactly what they need to do and just want to verify the syntax before applying. (very wise)
This reference is perfect for these cases where you want to jump to the scenario and find examples for both CentOS and Ubuntu distributions.
I love anything that makes my life easier and thought you might too. Hopefully you have this gives you the confidence to ditch the allow any any rule (or service iptables stop). Good luck and be safe(r)!