Linux

if you use docker, docker ignores ufw rules

I like firewalld. Its also used on many enterprise distros (RHEL, SLES).

But if you just have to open one port for something, just use what's installed on your distro.

How often are you going to be managing ports?

Just use any tool you like, all they do is fiddle with the Kernel's filter table.

@merompetehla UFW and firewalld provide a higher level of control, which means that they are quicker to learn, easier for simple tasks but harder to use in more granular levels. Their setup is translated into iptables rules at the end. With Iptables or its successor Nftables, you'll need to invest a bit more time to learn but have a more granular level of control at the end. I hope this helps.

OS is xubuntu 24.04

Ubuntu defaults to ufw. That, by itself, justifies the use of ufw in your case.

IMO firewalld because it's going to be more portable knowledge.

I found firewalld had so many options that it was a bit overwhelming at first, especially understanding how zones were actually meant to be used, and how each zone had a default handover for the unhandled traffic. But OpenSUSE has a GUI for it so I was able to make sense of it. UFW seemed pretty user friendly and atraight forward.

Network Filter Tables (NFT) is the current system. https://wiki.nftables.org/wiki-nftables/index.php/Main_Page

I like iptables + opensnitch

Iptables. Because in the end its iptables, so I learned it from the beginning „the right way“ and i am therefore not locked into one or another