During a session I missed at TechEd 2010 in Berlin, the Microsoft Exchange Team announced that they for most circumstances don’t recommend Windows Network Load Balancing for the CAS role anymore. Instead of recommending their own solution, which is still recommended in the online documentation, Microsoft now recommends the use of Hardware Load Balancers. Steve Goodman wrote down the relevant parts of Ross Smith IV’s session in a blog on his website. If you want to see the whole session, watch the session from this blog.
Windows NLB not recommended for CAS anymore
26/11/2010