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
applicat ions that view the physical ordering of the units within the stack.
Some characteristics of the base unit are described in the following sections.
Initi al In s ta l la ti o n
During the initial installation of the stack, the softwar e auto matica lly determines
the p hysical order of al l units i n the s tack accor ding to the position of the b ase 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 Unit s” 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
configuratio n (up to 8 u nit s) i s rea ched. I f you cha nge t he bas e un it t o anot her un it
in the st ack, the new base unit keeps its original unit number in the stack.
Note: For s tac ki ng t hr ee o r mor e 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 bandwidt h 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