Third-party hardware load balancers provide numerous options to control exactly how the load is to be balanced and or distributed. They are not restricted to only web traffic—they can often be configured to handle arbitrary protocols. When you have esoteric workloads that you need to put behind a load balancer, these hardware boxes are still the most feature-rich option available.

In a vCloud Director environment the most straightforward way to use hardware load balancers is by putting the backend (load to be balanced) virtual machines on a directly attached organization virtual datacenter network that is shared with the backend connection of the load balancer. This is usually thought of as a DMZ network. The load balancing logic is then contained in the load balancer and the vCloud Director-based virtual machines are used as pure compute resources.

In Figure 35 the DMZ network is a vApp or organization virtual datacenter network that is bridged to the external network. The public network could be any physical networking that routes to where the clients are located.

When evaluating the use of hardware based load balancers, the higher per port cost must be weighed against the availability of multiprotocol support and other advanced load balancing options.