Datasheet

52 Chapter 1
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Planning for the Installation of Windows 7
Activation validity interval After activation by a KMS host, KMS clients will remain acti-
vated for 180 days. If the KMS client has not connected to a KMS server within 180 days,
the activation will be invalidated. Clients attempt to connect every seven days, and when
they connect, this 180-day counter is reset.
Activation count The current number of clients that are being activated by KMS is tracked
using unique client machine identification designation (CMID) records. Clients attempt to
contact the KMS server every seven days, and the KMS server renews this CMID when the
client activates or reactivates. If the client doesn’t renew within 30 days, the CMID is dis-
carded and is no longer counted toward the activation threshold.
This is an important concept. Your network may have reached the threshold of 25, and
then two systems are decommissioned or taken on the road by sales people. Within 30 days,
the CMID for these two systems will be removed from the KMS host, and the count will
be at 23. Clients will no longer be activated, and within seven days all 23 remaining sys-
tems will be trying to activate every two hours. Even though the clients will stay activated
for 180 days, these failures will result in errors in the event logs. Once two new clients are
added to the network, everything will normalize.
KMS Activation Process
The KMS activation process is ongoing, requiring the KMS clients to connect to the KMS
host periodically. Before the process can start, an SRV record must exist in DNS so the
clients can reach the KMS server.
Normally, dynamic update will be configured in DNS, which allows the KMS service on
a KMS host to publish SRV records automatically to DNS. Once this is configured, no fur-
ther steps are required. KMS clients then query DNS to locate the KMS host.
DNS is a critical component of the KMS activation process. If KMS clients
can’t locate the KMS host because the SRV records aren’t published in
DNS, activation won’t occur. If KMS was working and has stopped, DNS
should be checked to ensure the KMS host record exists. These records
will be in the
_VLMCS._TCP folder on the DNS server.
Once the KMS client has located the KMS host, the following process is used to tempo-
rarily activate the client:
1. Every seven days, KMS clients query DNS for the IP of a KMS host.
2. KMS clients then try to renew their activation with KMS.
a. If the activation fails, clients continue to try every two hours.
b. If clients can’t connect to the KMS host for 30 days, the record for the client in the
activation count is deleted on the KMS server. If the activation count falls below
the activation threshold, the KMS host will stop activating clients.
c. If clients can’t connect for 180 days, client activation expires.
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