Extreme Networks ExtremeWare Command Reference Manual page 1388

Stacking Commands
stack are considered to be stack members. Because the stack manager maintains all of the software tables,
stack members need only run a sub-set of ExtremeWare.
An easy way to understand a stack is to think of a stack being a virtual chassis. Each stack member acts
as if it were a slot in a chassis and waits for configuration information from the stack manager. The
high-speed stacking links are like the backplane of the stack and are called stacking ports.
The stack manager stores any configuration information for the stack in its primary or secondary flash
memory. Because the stack manager has the knowledge of the state and the configuration of all the
other switches in the stack, it can respond to all external requests for those switches. For example, the
stack manager can respond to a request for SNMP information from all ports within the stack.
Stack Discovery and Manager Election
The order in which ExtremeWare assigns the stack manager and the stack members is called stack
discovery. The process of determining the stack manager for the stack is referred to as the election of the
manager. If stacking is enabled at switch startup, the switch comes up running the sub-set of
ExtremeWare. Stack discovery starts by sending and receiving probe packets among the members of the
stack until all the members are known. The priority of each switch is evaluated and if one switch alone
has the highest priority, that switch is elected as the manager. If two or more switches have the same
priority, the switch with the lowest MAC address is elected the stack manager. The remaining switches
are assigned a stacking ID based upon the same evaluation of their priority and MAC address. The
stack manager runs from this point with the full version of ExtremeWare.
1388 ExtremeWare 7.5 Command Reference Guide