Offline address book in exchange 2016 not updating
The Identity parameter specifies the GUID, distinguished name (DN), or OAB name that represents a specific OAB.You can also include the path by using the format Server\Offline Address Book Name.
Clients never connect directly to this backend location.
Exchange Server contains the improvements to OAB generation that were introduced in Exchange 2013 Cumulative Update 7 (CU7): To find all organization mailboxes, and the organization mailbox that's defined for an OAB, see Use the Exchange Management Shell to find organization mailboxes.
The OAB files are generated and stored in the designated organization mailbox, so the destination for OAB download requests is the Mailbox server that holds the active copy of the organization mailbox.
By default, this organization mailbox is responsible for generating all OABs (the first OAB named Default Offline Address Book, and any new OABs that you create).
You can create additional organization mailboxes to generate OABs.