In multi-node installations, the following ports allow traffic to internal services, such as:

• Monitoring node status
• Synchronizing data between nodes

You don't need to manually open these ports in the firewall of the host machines, as running the following commands will automatically opens them:

• The clusterctl install command executed when Running clusterctl install.
• the clusterctl backup restore and clusterctl node add commands executed when Administrating

However, ensure no network restriction blocks access to these ports.