Avaya 3500 Series Installing page 21

Figure 4: Simplified three–switch stacking illustration
1. Base Unit
2. Cascade/Stack Cable
3. Cascade/Stack Cable (Used for return)
Initial installation unit number assignment
When you install 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.
For example, when you initially power the stack, the base unit becomes unit 1 and the unit that
the base unit connects to (across the Cascade Down cable) becomes unit 2. The next unit is
designated as unit 3, this continues until the maximum stack configuration (up to eight units)
is reached. If another unit in the stack is designated as the base unit, the new base unit keeps
its originally designated unit number in the stack.
Stack MAC address
When a switch participates in a stack configuration, stack initialization automatically assigns
a stack MAC address. The stack MAC address is the base unit MAC address plus 1. If another
unit in the stack is assigned as the base unit, the new stack MAC address is the MAC address
of the new base unit plus 1. The original stack IP address still applies to the new base unit.
Avaya Ethernet Routing Switch 3500 series stacking
February 2013 21