Technology and Technology

Introduction Firewalld is a complete firewall solution available by default on CentOS 7 servers. In this guide, we will cover how to set up a firewall for your server and show you the basics of managing the firewall with the firewall-cmd administrative tool. Basic Concepts in Firewalld Before we begin talking about how to actually use the firewall-cmd utility to manage your firewall configuration, we should get familiar with a few basic concepts that the tool introduces. Zones The firewalld daemon manages groups of rules using entities called "zones". Zones are basically sets of rules dictating what traffic should be allowed depending on the level of trust you have in the networks your computer is connected to. Network interfaces are assigned a zone to dictate the behavior that the firewall should allow. For computers that might move between networks frequently (like laptops), this kind of flexibility provides a good method of changing your ru...