sudo apt-get install firewalld
Next, start firewalld and enable it to auto-start at system boot, then check its status.
sudo systemctl start firewalld
sudo systemctl enable firewalld
sudo systemctl status firewalld
CephMonitors 之间默认使用 6789 端口通信
sudo firewall-cmd --zone=public --add-port=6789/tcp --permanent
sudo firewall-cmd --reload