I have followed documentation about setting up co-existence between Exchange 2010 and 2016. I have all the Updates and service packs installed. I'm using a single name space for all the virtual directories, same name space for 2010 and 20169, cert imported to 2016 from 2010. Its only 1 AD site, and 1 2010 Exchange server and 1 2016 Exchange server. NTLM is enabled on 2010 CAS, everything is done by the book. To test, I created a host file on a desktop, pointing it to the IP address of the 2016 Exchange server and name space. Example:
If I open outlook it now prompts me for a user name and password, and once entered it continues to prompt and i cant connect.
The online helps seem to tell me to do the things that are already done. Has anyone resolved this and is my test method and acceptable method. I made no DNS changes, only the host file on a desktop with outlook 2016 to point to Exchange 2016 and the name space. I have also tried this on desktops with Outlook 2013 SP1 and I added hotfixes to Exchange 2010. I have tried everything with no luck. Any advice would be great.
Also all the mailboxes are located on the Exchange 2010 DBs, now if you access the Exchange 2016 web console you can see the 2010 environment along with the mailboxes on the 2010 server, but once I open outlook I get the user name and password prompt and cant get pass it.