Anthos on bare metal requires a Layer 4 network load balancer. It supports two load balancer options: bundled and manual.
In bundled load balancing, Anthos on bare metal deploys Layer 4 load balancers at the time of cluster installation. External load balancer is not required in this case. The load balancers can run on a dedicated pool of worker nodes, or they can be located on the same nodes as the control plane. Since the load balancers broadcast ARP messages to announce VIPs, all the nodes must be on the same Layer 2 subnet.
In manual load balancing, Anthos on bare metal does not deploy load balancers for clusters. We must configure an external load balancer before installing the cluster.
Before the cluster installation, we must configure our clusters control plane VIP on an external load balancer. After installation, we must configure the load balancer for the Kubernetes services and ingresses in the cluster.