Server 2008R2 SP1, EX2010 SP1 rollup2 I ran setup to reinstall the CAS role, event viewer was reporting errors saying it wasn't installed. The setup errored out after /prepareschema and/or /preparead. Since then, my owa stops after 6-8 hours, with exception errors, and my nltest /dsgetsite comes back with a status 1919, getting dc name failed. A restart of the Exchange Mailbox Assistants service restores OWA, while a nltest /dsgetdc:domain /force restores the previous nltest. Another concern is the services that got set to disabled, while setup tried to run. I hope I found all those as well. Any help would be appreciated.

HI John, Per your description, you already had a exchange 2010 email system, and you reinstalled the CAS role on the old CAS server, right? Why do you want to reinstall it, and how do you reinstall it? If you want to recover a exchagne server role, Please refer to below information: http://technet.microsoft.com/en-us/library/dd876880.aspx Other information about how to deploy the exchange 2010 email system: http://technet.microsoft.com/en-us/library/aa996719.aspx http://technet.microsoft.com/en-us/library/bb123715.aspx http://technet.microsoft.com/en-us/library/bb691354.aspx NOTE, please firsly confirm the DCs are healthy. Regards! Gavin TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com 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.

Yes, it is a previous install. I just wanted to clear the errors in event viewer saying cas role not installed. But I think the setup /prepareAD and /prepareschema left something undone. For now, the NLTEST failure and OWA failures occur at the same time. Event viewer is reporting 2601,2604,2501 errors, and DNS is valid. And NLTEST /DSGETSITE fails status 1919, and the NLTEST /dsgetdc:domain /force restores functionality. This can happen within minutes or hours after the last instance, and I'm not sure why it can't resolve the DC on it's own.

So I gotten it narrowed down to the active directory side of things. nltest /dsgetsite fails after awhile. A nltest /dsgetdc command correctly queries the dc, and nltest /dsgetsite returns a good value. Then after some time, it fails again, and needs to be corrected with /dsgetsite again. the failure of not seeing the dc is causing exchange issues. Where is this hiccup that needs to be cleared, to return the correct ability to see the dc without the manual /dsgetsite?

Hi John, Any event log on the DC server, how about use the DCDIAG to retrieve some information, any error? If there are some issue, please post the issue on the Server Forum, you will get more hlep to resolve the DC issue. And then, we could resolve the exchange related issue, what about the exactly event log error related with CAS, could you please post them here. Did you install all the server roles on the same server box? Are there some event log related with HUB and Mailbox server roles? How about uninstall it If it is a test lab, I would start all over again, it seems some requisites not be prepared properly. Regards! Gavin TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.comPlease 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.