1-2 
you can configure and manage all the member devices through the management device without 
the need to log onto them one by one. 
z  It provides the topology discovery and display function, which assists in monitoring and maintaining 
the network. 
z  It allows you to configure and upgrade multiple switches at the same time. 
z  It enables you to manage your remotely devices conveniently regardless of network topology and 
physical distance. 
z  It saves IP address resource. 
Roles in a Cluster 
The switches in a cluster play different roles according to their functions and status. You can specify the 
role a switch plays. A switch in a cluster can also switch to other roles under specific conditions. 
As mentioned above, the three cluster roles are management device, member device, and candidate 
device. 
Table 1-1 Description on cluster roles 
Role  Configuration  Function 
Management device 
Configured with a 
external IP address 
z  Provides an interface for managing all the 
switches in a cluster 
z  Manages member devices through command 
redirection, that is, it forwards the commands 
intended for specific member devices. 
z  Discovers neighbors, collects the information 
about network topology, manages and 
maintains the cluster. Management device 
also supports FTP server and SNMP host 
proxy. 
z  Processes the commands issued by users 
through the public network 
Member device 
Normally, a member 
device is not 
assigned an 
external IP address 
z  Members of a cluster 
z  Discovers the information about its neighbors, 
processes the commands forwarded by the 
management device, and reports log. The 
member devices of a luster are under the 
management of the management device. 
Candidate device 
Normally, a 
candidate device is 
not assigned an 
external IP address 
Candidate device refers to the devices that do not 
belong to any clusters but are cluster-capable. 
 
Figure 1-2 illustrates the state machine of cluster role.