Datasheet

Planning and Managing Client Licensing and Activation 51
Two important concepts are worth repeating with KMS:
Activation is temporary. Clients are not permanently activated. Instead, they must peri-
odically connect to the KMS server to be reactivated. Temporary activation will last for 180
days.
KMS is used for a large number of clients. Specifically, KMS can be used only if there are
five or more servers or 25 or more clients and servers that need to be activated by KMS. If
the numbers fall below this threshold, KMS will stop reactivating clients.
You can download KMS for free. Go to
www.microsoft.com/downloads, and search for
“Key Management Service.” You can install it on Windows Server 2003, Windows Server
2008, or Windows Server 2008 R2.
If you’re running a KMS server on a Windows Server 2008 server, you can update it to
provide activation for Windows 7 and Windows Server 2008 R2. Knowledge Base article
968915 (
http://support.microsoft.com/kb/968915) provides the information on this
extension and links for the download.
At this writing, there isn’t a single download for KMS to support Windows 7
and Server 2008 R2. You must install the earlier version and then extend it
using KB 968915. However, I expect it’s just a matter of time before Micro-
soft releases a single-version download.
KMS Activation Terms
When discussing the Key Management Service (KMS), it helps first to understand the dif-
ferent terms associated with KMS. Once you grasp the terms, the process is much easier to
understand. I’ve outlined many of the basic terms here:
KMS host The server hosting the KMS service is commonly referred to as the KMS host.
KMS client Clients configured to contact the KMS host are referred to as KMS clients.
DNS publication A KMS host can publish Domain Name System (DNS) SRV records
(server records) to the DNS server using dynamic DNS within a Microsoft domain. If DNS
isn’t configured to allow dynamic updates, the SRV records must be manually configured
on the DNS server so that KMS clients can locate the KMS host.
Activation threshold The minimum number of clients a network must have for KMS
activation to work is referred to as the activation threshold. A network must have at least
5 servers for server activation to work or a combination of at least 25 servers and clients
for client activation to work. The KMS host tracks this threshold, and if the threshold isn’t
reached or the number of clients falls below this threshold, it will no longer activate the
clients. KMS clients that aren’t activated because the activation threshold is not met will
request activation every two hours.
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