Web Farm with a Firewall


Topic Last Modified: 2005-05-24

The following figure illustrates a Web farm scenario.

Front-end and back-end topology in a Web farm

Network load balancing on Front-end servers

A corporation is deploying Outlook Web Access to 200,000 users. The goal is to have a single namespace (for example, https://mail) in which users can reach their mailboxes. Additionally, for performance reasons, the corporation wants to avoid having a bottleneck at the front-end server or a single point-of-failure, so they want to spread the load over multiple front-end servers by using Network Load Balancing (NLB). This scenario is referred to as a "Web Farm."

Although this is the only scenario that depicts NLB, you can use NLB to distribute load among front-end servers in any of the scenarios described in this guide.

For information about how to set up Network Load Balancing, see the Windows online documentation. Configuring Exchange on the front-end servers does not require any special steps.

As previously mentioned, the load-balancing solution you use should ensure that each user is always sent to the same front-end server for the duration of a session.