Hardware Load Balancing

NAT can be used for the Edge Servers only if an organization uses Lync’s built-in DNS load-balancing feature. Organizations that prefer to use hardware load balancers for the Edge Servers to support down-level clients or public IM connectivity are still required to use publicly routable IP addresses on the adapters. In this scenario organizations need publicly routable IP addresses for each Edge service, and each hardware load balancer VIP requires a separate public address. The end result is that hardware load balancing requires three additional public IP addresses.