Enabling firewalld in the system and reviewing the default zones

We have already seen that firewalld is enabled by default in the system. However, we may need to disable (that is, check whether the firewall is interfering with a service), re-enable (that is, after restoring configuration files), and start and stop it (that is, to reload configuration or to do a quick check). These tasks are managed like any other service in the system, that is, using systemctl. Let’s stop the firewalld service:

[root@rhel-instance ~]# systemctl stop firewalld
[root@rhel-instance ~]# systemctl status firewalld
○ firewalld.service - firewalld - dynamic firewall daemon
     Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled; vendor preset: enabled)
     Active: inactive (dead) since Mon 2022-05-09 08:45:54 CEST; 5s ago
       Docs: man:firewalld(1)
    Process: 725...