Nortel Networks 1000BASE-ZX Manual Do Utilizador

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Chapter 2 Network configuration
209418-A
Base unit
The base unit is the unique stack unit that you configure with the Unit Select 
switch on the front panel. One BayStack 420 Switch in the stack must be 
configured as the base unit; all other units in the stack must have their Unit Select 
switch set to Off (see 
 on 
). You can assign any single 
BayStack 420 Switch as the base unit.
The physical ordering of all of the other units in the stack is determined by the 
position of the base unit within the stack. This is important for network 
management applications that view the physical ordering of the units within the 
stack.
Some characteristics of the base unit are described in the following sections.
Initial installation
During the initial installation of the stack, the software automatically determines 
the physical order of all units in the stack according to the position of the base unit 
within the stack. Thereafter, the individual units maintain their original unit 
numbering, even if you change the position of one or more units in the stack (you 
can renumber the units using the Renumber Stack Units screen; see 
).
For example, when you initially power up the stack, the base unit becomes unit 1 
and the unit that the base unit connects to becomes unit 2 (and the next unit is unit 
3 and so on), until the maximum stack configuration (up to 8 units) is reached. If 
you change the base unit to another unit in the stack, the new base unit keeps its 
original unit number in the stack.
Stack MAC address
When the switch is participating in a stack configuration, a stack MAC address is 
automatically assigned during the stack initialization. The base unit’s MAC 
address, with a software offset, is used for the stack MAC address.
For example, if the base unit’s MAC address is 00-00-82-99-44-00, and the stack 
software offset is 
1F, 
then the stack MAC address becomes:
00-00-82-99-44-1F