Users Guide

44 Dell PowerConnect 55xx Systems User Guide
Stack Overview
The PowerConnect 5500 Stacking feature provides multiple switch
management through a single switch, so that all units in the stack are treated
as if they were a single switch. All stack members are accessed through the
management IP address, through which the stack is managed.
Each switch is a member in a stack, although the stack may consist of only a
single switch.
Up to eight units can be stacked.
This section covers the following topics:
• Stack Operation Modes
• Stacking Units
•Stack Topology
Stack Operation Modes
All stacks must have a Master unit, and may have a Master Backup unit. All
other units are connected to the stack as members (slaves).
A unit in the stack can be in one of the following modes:
• Stack Master — Runs the fully operational software of a switch. In
addition, it runs configures and manages all other units in the stack. All
protocols run in the context of the Master unit. It is responsible for
updating and synchronizing the
Master Backup .
The Stack Master detects and reconfigures the ports with minimal
operational impact in the event of:
Unit failure
Inter-unit stacking link failure
Unit insertion
Unit removal
When the Master unit boots, or when inserting or removing a stack
member, the Master unit initiates a stacking discovering process.