Setting the Anchor priority for the primary controller to 1 ensures that clients connect to the primary controller first. The Anchor priority is a value assigned to each controller within a mobility group to determine the order in which clients should connect to the controllers. A lower priority value has higher precedence. Therefore, by setting the primary controller's Anchor priority to 1, it becomes the preferred controller for client connections. If the primary controller fails, clients are then pushed to the secondary controller, which should have a higher Anchor priority value.