Here is the scenario. We have our primary site with 2 servers running the MB role and 1 server running the CAS / HT role. Everything was fine until we installed two additional mailbox servers and one CAS /HT server at the secondary site. We added the mailbox servers to the DAG and created database copies on the new servers at the secondary site.
Now all of a sudden, several users are connecting to the CAS server at the secondary site and are unable to connect to their mailboxes. After receiving dozens of call from such users, we shutdown the CAS server at the secondary site ad that has somewhat helped and users (after rebooting their machines) are able to connect to outlook. Also, somehow, the some of the mailbox databases got activated on the secondary site servers, when they should not.
Question: how can we prevent users from connecting to the CAS server in the secondary site and 2) why did the databases switchover to the secondary site. If there is an issue with the mailbox server at the primary site, we have another mailbox server with copies of the active database at the primary site with activation preference to become the active server.