Operation Manual – ClusterH3C S5600 Series Ethernet Switches Chapter 1 Cluster1-4Figure 1-2 State machine of cluster rolez A candidate device becomes a management device when you create a cluster onit. Note that a cluster must have one (and only one) management device. Onbecoming a management device, the device collects network topology informationand tries to discover and determine candidate devices, which can then be addedto the cluster through configurations.z A candidate device becomes a member device after being added to a cluster.z A member device becomes a candidate device after it is removed from the cluster.z A management device becomes a candidate device only after the cluster isremoved.Note:After you create a cluster on an S5600 switch, the switch collects the network topologyinformation periodically and adds the candidate switches it finds to the cluster. Theinterval for a management device to collect network topology information is determinedby the NTDP timer. If you do not want the candidate switches to be added to a clusterautomatically, you can set the topology collection interval to 0 by using the ntdp timercommand. In this case, the switch does not collect network topology informationperiodically.1.1.3 How a Cluster WorksHGMPv2 consists of the following three protocols:z Neighbor Discovery Protocol (NDP)z Neighbor Topology Discovery Protocol (NTDP)z ClusterA cluster configures and manages the devices in it through the above three protocols.
