Stacking Overview; Principle Of Stacking - Huawei V100R006C00 Configuration Manual

Quidway S5700 Series Ethernet Switches
Configuration Guide - Device Management

3.1 Stacking Overview

This section describes the basic concepts of the stacking function.
The stacking function indicates that multiple devices that support the stacking function are
connected together to logically function as one device. Up to nine stack devices are connected
through stack cables in a ring or link topology. All stack devices logically function as one device
to forward packets. Roles of devices in a stack are as follows:
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The master switch, standby switch, and all the slave switches are all member switches.
Interfaces connecting member switches are stack interfaces, and other interfaces are common
user interfaces. Member switches are connected through independent stack modules and stack
cables.

3.2 Principle of Stacking

This section describes how a stack system is set up.
Prerequisites for Setting Up a Stack System
To successfully create a stack system, complete the following tasks:
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Issue 01 (2011-07-15)
Master switch
A stack has only one master switch. The master switch manages the entire stack system by
assigning stack IDs to member switches, collecting information about the stack topology,
and notifying all the member switches of the information.
Standby switch
A stack has only one standby switch. The standby switch backs up the master switch. When
the master switch is faulty, the standby switch functions as a master switch.
Slave switch
The slave switch sends packets to inform the master switch of the topology change after
detecting that a neighbor is lost. Apart from the master switch and standby switch, all the
other switches in a stack are slave switches.
Configure the same software version for all the member switches. When the master switch
detects that a new member switch runs a different version, the master switch synchronizes
system version of the member switch.
NOTE
l When the products of the same series are stacked, the switch that is closest to the physical interface
of the new member switch added to the stack system synchronizes the system version of the new
member switch.
l If no switch in the stack system is of the same series as the new member switch or the system
version of the new member switch cannot be synchronized to the master switch version, the new
member cannot join the stack system.
Use the devices of the same type (for example, EI devices or SI devices) as the member
switches of a stack system. The EI devices and SI devices cannot be used in the same stack
system.
Connect all devices by using leased stack cables and stack modules.
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