Meu firewall está inativo no momento.
systemctl status firewalld firewalld.service Loaded: masked (/dev/null) Active: inactive (dead)
Eu usei o seguinte comando para ativar o firewall
# systemctl unmask firewalld
mas eu recebi este erro:
# systemctl unmask firewalld
Failed to issue method call: Access denied
# sudo systemctl restart firewalld
Failed to issue method call: Unit firewalld.service failed to load: No such file or directory.
# sudo systemctl enable firewalld
Failed to issue method call: Access denied
lsmod | grep iptab
mostrar módulos carregados?