I have six 2008 R2 terminal servers and one 2008 R2 broker server and I am using DNS round robin to manage client connection requests. When I have take a server out of the farm for maintenance I start with draining the users then I remove the server from the session brokers local session broker computers group, however I receive many complaints that the session broker still attempts to connect users to the server that I took out of production. So in addition to the above steps I have also been removing the DNS records for that server on the domain controller then re-creating them when I want to bring it back online. I have the keep alive on the DNS records reduced to 2 minutes from the default of an hour. I do not understand why the session broker is still passing connection requests to the offline server.