There is an api call that gives you this information in a more standard way.
This will give you the guid, license hash, and you can tell if the server is a license manager or not by comparing the master_guid and slave_id fields. If they are the same, you are talking to your license manager, and if they are different, you are dealing with a server with a license managed by another server.
For license managers, you can call:
This will give expiration and start date info for all licenses that come with that server. Slave servers will not have any of this information here.
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