4
Building Stacks
Planning to Create Your Stack
Setting up the Physical Stack
Managing Stacks
A stack consists of a group of up to four 220 series switches that are connected to form a logical ring.
The stack offers the combined port capacity of the individual switches – but it operates as if it were a
single switch, making network administration easier.
This chapter describes the ways in which you can set up stacks, the things to consideration when
planning stacks, and the steps for setting up the hardware. We recommend that you read this chapter
before installing the switches that will make up the stack.
For information about configuring stacks and managing them on a day-to-day basis, see
ExtremeSwitching 200 Series: Administration Guide
.
Planning to Create Your Stack
Use the information in the following topics to plan the physical makeup of your stack – including
switches and cables – and the stacking protocols you will use. Included are:
•
Guidelines and other information for each switch model in your stack
•
Considerations for combining different switch models in a stack
•
Information about stacking cables
For additional considerations, refer to
ExtremeSwitching 200 Series: Administration Guide
Stack Topology
A stack is the collection of all switches, or units, that are cabled together to form one virtual switch.
One of the switches, called the stack manager, serves as the single point of control for managing the
stack. Any stack member can be the stack manager (unless its priority is set to 0).
When the stack is formed, one of the units is selected – either either automatically or using the
standby
command – as the standby. If the stack manager fails., the standby automatically takes over
as stack manager. All of the stack members detect the failure, and the stack continues to forward
network traffic with minimal disruption.
All other switches in the stack are stack members. The stack members use stacking technology to
behave and work together as a unified system. Layer 2 and Layer 3 protocols present the entire switch
stack as a single entity to the network.
ExtremeSwitching 210 and 220 Series Switches: Hardware Installation Guide
52
