Does Windows AD be used in vCenter link-mode(For vSphere 5.X and 6.0) ?
Linked mode group in vSphere 5.x makes use of ADAM.
but Enhanced Linked Mode in vSphere 6 doesn't rely on ADAM, it makes use of VMware Directory service (VMDir)
Should all vCenter be the same version in the same link-mode group ?
- Only same build number of vCenter Server must be joined in a Linked Mode group.
Ref: VMware KB: Understanding the Linked Mode options for vCenter Server 5.1.x and 5.5.x