Nortel Networks 2500 Series Initial stack installation, Stack MAC address, Stack configurations

Stack configuration 49

1.Base Unit

2.Cascade Cable

3.Cascade Cable (used for return)

Initial stack 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 the position of one or more units in the stack is changed.

For example, when the stack is initially powered, the base unit becomes unit 1 and the unit that the base unit connects to (via the Cascade Down 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 the base unit is changed to another unit in the stack, the new base unit keeps its original unit number in the stack.

Stack MAC address

When a switch participates in a stack configuration, a stack MAC address is automatically assigned during stack initialization. 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.

Stack configurations

Due to stack parameters being associated with the base unit, the physical stack order depends on the base unit position and whether the stack is configured cascade up (stack up) or cascade down (stack down). This designation depends on the stack cabling arrangement.

The system automatically numbers the physical units based on the designated base unit (Unit 1). In a cascade down configuration, the base unit is physically located as the top unit in the stack. The cable connected to the Cascade Down connector of the base unit terminates in the Cascade Up connector on the next unit in the stack which is physically located below the base unit. This next unit is designated Unit 2. The stack is wired downward through the units and the system continues to number in this manner throughout the stack. In this configuration, the base unit discovers the stack in a cascade down (stack down) direction. The following illustration demonstrates a cascade down (stack down) configuration.

Nortel Ethernet Routing Switch 2500 Series

Overview — System Configuration

NN47215-500 (323162-B) 02.02 Standard

4.1 19 November 2007

Copyright © 2007, Nortel Networks