I am planning on upgrading all of our Exchange servers to Cu15. We have 18 Exchange servers, (10 mbx and 8 cas, and yes they are separate servers). My question or concern is more around the .net framework versions. Currently all exchange servers are running CU13 with .net framework 4.6.1. Microsoft is recommending that we upgrade .net framework to 4.6.2. Considering the CAS servers are separate servers from the mailbox servers, if I upgrade a CAS server to 4.6.2, but the mailbox servers are at 4.6.1, will this cause any issues with OWA,EAS,outlook anywhere ? My plan was to upgrade the CAS servers first, then the mailbox servers, but considering we have 8 CAS and 10 MBX, it’s going to take some time before all 18 servers are at the same .net framework version. Any issues with having a CAS server at a higher level .net version from a mailbox server?
Bulls on Parade