Can I close all ports in the VPS vendors firewall and still get updates via Webmin?

SYSTEM INFORMATION
OS type and version Debian 11
Webmin version 2021

My goal is to close all ports for incoming traffic in order to make it as secure as possible. If I close all ports, will Webmin still get all updates? Or which ports should be open in this case?

All traffic to the VPS is made via the internal IP of the VPS. So for my own use there is no need for incoming traffic.

All outgoing traffic is wide open on all ports.

You don’t get updates “via Webmin”. You get updates via your package manager. Webmin provides a GUI for apt-get.

At least, assuming you installed Webmin in the recommended way, by adding the Webmin repository to your apt config and installed using apt.

Most firewalls will default to allowing outbound traffic and any inbound traffic in repsonse. I believe this is called state full.

But, I don’t know your VPS’s setup. Close up and see if you can initiate an outbound connection. You’ll know if it is two way because it answers.

OK. If rephrase the question. Does apt-get needs any open ports for outbound traffic? Or can Webmin be updated with all inbound traffic blocked?

Outbound traffic is unlimited. I want to limit inbound traffic to a minimum and close as many ports as possible. Hence my question.