Very Very Strange Situation I've 1 windows 2008 R2 and 1 Exchange 2010 SP1 as Mailbox and 1 Exchange 2010 SP1 as HUB/CAS Everything was working find till suddenly the HUB/CAS server rejected remote desktop and its page was dimmed so you cannot choose to re-enable remote desktop and the MS Exchange RPC Client Access Service is not running and if tried to run it it says the service started then stopped, some services doesn't need to be run and when i try to add user permission to a folder it can display users from AD but when select user it says RPC Server Unavilable< and the server boots and shutdowns in very long time, and if tried to run DCDIAG it fails to connect to DC and cannot sync the clock with it automatically , how ever the OWA works fine send and receive but no way to connect outlook in exchange mode because of RPC Client Access service. i added tow additional DCs in another states and installed another HUB/CAS server< the server was working very good until i installed the exchange HUB/CAS< after restart everything happened again exactly !!! however all other servers workingvery good with the DC !! What to do ?

Seems like its something to do with network. Run the netdiag and post the result. Do you see anything in application LOG? Gulab | MCITP: Exchange 2010 | MCITP: Exchange 2007 | Skype: Gulab.Mallah | Blog: www.ExchangeRanger.blogspot.com

but it happens only for exchange hub/cas , not hapenning to scom or sccm ! however i think there is a policy stopping remote desktop and stopped or blocked RPC port even though the rpc service s running

Are the two additional DCs and Hub/CAS server with the problematic HUB/CAS server in the same forest? What’s the detail error message when running DCDIAG? At this stage, I suggest you temporarily turn off firewall and antivirus program to check the result. Meanwhile, please post the detail error message in Event log here for research. Thanks. Novak Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Hi, how many client connections do you expect to have to this server? There is a limitation of total possible connections 65000. I know the number is high but just in case.... RegardsZbynk

Did turning off firewall and antivirus work ?Dhruv