Server-determined client refresh periods (CRPS) for dynamic directory services are disclosed. In a dynamic directory maintained by a server, clients must send a refresh message to the server every CRP in order to persist in the directory. The server desirably initially sets the CRP for the clients, and is able to later change the CRP. This allows the server to increase the CRP for at least some of the clients as more clients log onto the server, to ensure that the server is able to timely respond to all the clients.