Nortel Networks 450 - Manual (Page 51)

BayStack 450 10/100/1000 Series Switches
302401-D Rev 00 1-25
Base Unit
The base unit is the unique stack unit that you configure with the Unit Select
switch on the front panel of the 400-ST1 cascade module. One unit 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
“Unit Select Switch ” on page 1-24 ). You can
assign any single unit in the stack 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 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 “Renumber
Stack Units” on page 3-65).
For example, when you initially power up the stack, the base unit becomes unit 1
and the unit that the base unit connects to (via the Cascade A Out cable) 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.
Note: For stacking three or more units (maximum 8 units per stack), order the
optional 1 meter (39.27 inch) cascade max-return cable (Bay Networks Order
No. AL2018001).
Note: Although you can assign any single unit in the stack as the base unit,
when mixing supported BayStack switch models in a single stack, Nortel
Networks recommends that you select the unit with the highest bandwidth to
be the base unit. The additional workload of the base unit is optimized by
using the higher bandwidth switch model.
kombk.book Page 25 Tuesday, June 29, 1999 3:25 PM