Cisco sfe2000 ユーザーガイド

Chapter

manually assigned Unit ID, the Stack Master cannot change it. If the incoming unit 
cannot be assigned an available Unit ID, then it is shut down and is not joined to the 
stack. 

3. The Stack Master performs unit and port configuration for the incoming unit.

• Any configuration information that is relevant to the number assigned to the 

incoming unit is applied by the Stack Master. For example, if the incoming unit is 
assigned the same Unit ID of the unit it replaced, then when possible, it receives the 
same configuration as the failed unit.

• If the incoming unit is identical to the replaced unit, the entire configuration of the 

replaced unit is applied to the incoming unit and the stack returns to the state it was 
in before unit failure. 

If the incoming unit is not identical to the unit that failed, the Stack Master applies the 
configuration in the following manner:

• If a 24-port unit replaces a failed 48-port unit, the ports of the incoming unit are 

configured according to the configuration of the first 24 ports of the failed unit. 

• If a 48-port unit replaces a 24-port unit, then the first 24 ports of the incoming unit 

are configured according to configuration of the ports of the failed unit. The 
remaining ports of the incoming are configured according to the default settings. 

• If the units have uplink ports, then the first uplink port of the incoming unit is 

configured according to the configuration of the first uplink port of the failed unit.

When the Stack Master unit fails, the stack Backup Master, using the Master Discovery 
process, discovers that the Stack Master unit no longer responds. The Backup Master takes 
over as the Stack Master. The Backup Master (now the Stack Master) directs all other stack 
members to route unit-to-unit traffic around the failed unit using the ring topology of the 

The configuration of all 48 ports of the failed unit 

is kept in memory, even though the first 24 are currently 
applied. If, in the future, a 48 port unit is inserted and 
assigned the same Unit ID, it is configured the same as 
the original failed 48-port unit.