Planning DNS Server Configuration

The default KMS auto-publishing feature requires SRV RR and DDNS support. Microsoft DNS or any other DNS server that supports SRV RRs (per Internet Engineering Task Force [IETF] RFC 2782) and dynamic updates (per RFC 2136) can support KMS client default behavior and KMS SRV RR publishing. Berkeley Internet Domain Name (BIND) versions 8.x and 9.x support both SRV records and DDNS, for example.

The KMS host must be configured so that it has the credentials needed to create and update SRV, A (IP version 4, or IPv4), and AAAA (IP version 6, or IPv6) RRs on the DDNS servers, or the records need to be created manually. The recommended solution for giving the KMS host the needed credentials is to create a security group in AD DS and add all KMS hosts to that group. In the Microsoft DNS server, ensure that this security group is given full control over the _VLMCS._TCP record on each DNS domain that will contain the KMS SRV RRs.

Activating the First KMS Host

KMS hosts on the network need to install a KMS key and then be activated with Microsoft. Installation of a KMS key enables the KMS on the KMS host. After installing the KMS key, complete the activation of the KMS host by telephone or online. Beyond this initial activation, a KMS host does not communicate any information to Microsoft.

KMS keys are installed only on KMS hosts, never on individual KMS clients. Windows 7 and Windows Server 2008 R2 have safeguards to help prevent inadvertently installing KMS keys on KMS client computers. Any time users try to install a KMS key, they see a warning, but they can continue to install the KMS key.

Activating Subsequent KMS Hosts

Each KMS key can be installed on up to six KMS hosts, which can be physical computers or VMs. After activating a KMS host, the same host can be reactivated up to nine more times with the same key.

If the organization needs more than six KMS hosts, IT professionals can request additional activations for the organization's KMS key. An example of this would be if 10 separate physical locations were under one Volume Licensing agreement, and IT wanted each location to have a local KMS host. To request this exception, call the Activation Call Center. For more information, see the Volume Licensing Web site at http://go.microsoft.com/fwlink/?LinkID=73076.