Our client has a single AD forest (mydom.local) with multiple sites. They have Exchange 2016 running in DATABASE Availablity Group (DAG). The tech wants to extend the AD schema because of the CU updates. He says that he has to extend the AD schema at both DAG place (prod and DR). As I understand there is no need to do multiple times since there is only one schema master. Experts our there, you must have updated CUs several times, Could you please shed light on this?
1. Does CU update need AD schema update or Exchange schema update?
2. Do we have to update the schema at both places?