SMS: Client Access Point and Distribution Point Selection

Systems Management Server (SMS) clients use existing connections from the Client Access Points (CAPs) and Distribution Points (DPs) designated in their site by default. If no existing connection exists, clients randomly select from the CAP/DP list for their site. Sites are defined by local or fast network connectivity, ensuring load balancing across all CAPs and DPs in the site.

In some situations, a site may manage a handful of clients across a slow link. Although this is not a recommended configuration, there are provisions in the SMS 2.0 architecture to force a client to use a specific CAP or DP. When you consider an implementation where specific clients have a designated CAP or DP, keep in mind that clients that do not explicitly have a preferred CAP or DP identified, select their servers randomly. In other words, if a CAP or DP is available over a slow link, it still may be chosen by a local client that does not have designated preferred servers. Defining a site that includes wide area subnets is not recommended as it negates the SMS 2.0 architecture.

For more information about site boundaries and hierarchy configuration, refer to Chapter 3 (Planning for SMS in Your Organization) and Chapter 9 (Discovering Resources and Installing Clients) in the Microsoft Systems Management Server 2.0 Administrator's Guide.

Clients can use the following three methods to determine which CAP or DP to use (listed in order of attempted use):

• Preferred
  Connections are attempted to shares that have been assigned to the preferred list and the CAP/DP list. This method is disabled by default. You can specify preferred servers using the Prefserv tool (Prefserv.exe), which is included with the Microsoft BackOffice 4.5 Resource Kit.
• Existing Connection
  The current list of connections is checked for matches against the shares in the CAP/DP list. The first existing connection is reused. This method is enabled by default for configurations where workgroups, by way of a drive mapping at logon, default to designated application servers, which also perform the role of a DP.
• Random
  A share is chosen randomly from the list. This method is enabled by default to ensure load balancing across a site.

It is possible to enable, disable, or otherwise configure each server selection method using the Prefserv tool. For additional information about this topic, click the article numbers below to view the articles in the Microsoft Knowledge Base: