Installation Guide

Building Stacks
Introduction to Stacking on page 51
Planning to Create Your Stack on page 60
Setting up the Physical Stack on page 65
A stack consists of a group of up to eight switches that are connected to form a ring. The stack oers
the combined port capacity of the individual switches. But it operates as if it were a single switch,
making network administration easier.
Stacking is facilitated by the SummitStack feature – part of the ExtremeXOS Edge license.
This chapter describes the supported configurations for stacking switches, the considerations for
planning a stack, 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.
Refer to the Stacking chapter in the ExtremeXOS 31.1 User Guide for information about configuring a
stack, maintaining the stack configuration, and troubleshooting.
Introduction to Stacking
Using the SummitStack feature—part of the ExtremeXOS Edge license—a stack can combine switches
from dierent series, provided that every switch in the stack:
• Runs in the same partition (primary or secondary).
• Runs the same version of ExtremeXOS.
• Includes support for stacking.
The stack operates as if it were a single switch with a single IP address and a single point of
authentication. One switch – called the primary switch – is responsible for running network protocols
and managing the stack. The primary runs ExtremeXOS software and maintains all the software tables
for all the switches in the stack.
All switches in the stack, including the primary switch, are called nodes. Figure 35 shows four nodes in a
stack, connected to each other by SummitStack cables.
All connections between stack ports must be directly between switches. A stacking connection cannot
pass through a third device, for example a Virtual Port Extender or an LRM/MACsec Adapter.
ExtremeSwitching 5520 Series Hardware Installation Guide
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