How to disable new connections on a CAS

Hi All,

I'm actually reading the Upgrade Exchange 2010 to Exchange 2010 SP2 document, and when updating the the CAS, Microsoft recommend to disable new connection on CAS server, part of a load balanced array members, and proceed to the upgrade when all connections are closed.

In our environment, we do not have a load balanced array. Only a Cluster of 2 CAS / HUB servers.

1rst question : should I proceed the same way by putting offline 1 of my 2 CAS server, update it to SP2 and do the same with the second CAS server?

2nd question : How can we disable new connection on a CAS server?

Best regards,

Johnny