Proxmox VE comes with a robust firewall ready to be configured out of the box. This firewall can be configured to protect the entire Proxmox cluster down to a virtual machine. The per-VM firewall option gives you the ability to configure each VM individually by creating individualized firewall rules, a prominent feature in a multi-tenant virtual environment. We will learn about this feature in detail in Chapter 9, The Proxmox VE Firewall.