Load balancer options in GKE on Bare Metal
GKE on Bare Metal supports two load balancer options: bundled and manual.
Bundled load balancer mode
If you choose bundled load balancing, GKE on Bare Metal deploys Layer 4 load balancers during cluster installation. An external load balancer is not needed. 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.
All nodes that run load balancers must be on the same Layer 2 subnet because load balancers broadcast ARP messages to announce VIPs.
See Configuring bundled load balancing for configuration information.
The following diagram shows an example network topology where bundled load balancers are located on the control plane nodes.
Manual load balancer mode
If you choose manual load balancing, GKE on Bare Metal does not deploy load balancers. This allows more flexibility than bundled load balancing and there are no Layer 2 network requirements.
You must configure your control plane nodes' VIPs on an external load balancer before installing the cluster. After installation, you must pick a load-balancing solution for Kubernetes Services and Ingresses.
The following diagram shows an example network topology of a cluster using manual load-balancing mode with an external load balancer.