By maintaining a unique Virtual Service for each CAS service, you can manage each independently from one another. For example, you may wish to have different pool membership, server load balancing methods, or custom monitors for OWA and OA. If those services are each associated with a different Virtual Service, micro-management becomes easier.

Note: When using a unique Virtual Service for each CAS service, the same FQDN and port cannot be shared among the services. So for HTTPS-based services, you should use unique FQDNs for each CAS service and Virtual Service. This is a general limitation when load balancing services using layer 7.

The following sections contain steps necessary for creating a Virtual Service for each of the available CASs in Exchange 2010.