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Understanding How the Master in a Virtual Chassis Configuration Is Elected
All switches that are interconnected in a Virtual Chassis configuration are member
switches of that Virtual Chassis. Each Virtual Chassis configuration has one member that
functions as the
master
and controls the Virtual Chassis configuration.
When a Virtual Chassis configuration boots, the Juniper Networks Junos operating system
(Junos OS) for Juniper Networks EX Series Ethernet Switches automatically runs a master
election algorithm to determine which member switch takes the role of master.
The algorithm that the software uses to determine the master is as follows:
1.
Choose the member with the highest user-configured mastership priority (255 is the
highest possible value).
2.
Choose the member that was master the last time the Virtual Chassis configuration
booted.
3.
Choose the member that has been included in the Virtual Chassis configuration for
the longest period of time. (For this to be a deciding factor, there has to be a minimum
time lapse of one minute between the power-ons of the individual interconnected
member switches.)
4.
Choose the member with the lowest MAC address.
The variations among switch models, such as whether the switch has 48 or 24 ports, do
not impact the master election algorithm. To ensure that a specific member is elected
as the master:
1.
Power on only the switch that you want to configure as master of the Virtual Chassis
configuration.
2.
Configure the mastership priority of that member to have the highest possible value
(255).
3.
Continue to configure other members through the master member, as desired.
4.
Power on the other members.
Related
Documentation
Virtual Chassis Overview on page 921
•
•
Understanding Virtual Chassis Components on page 924
•
Understanding Virtual Chassis Configuration on page 934
Understanding Software Upgrade in a Virtual Chassis Configuration
A Virtual Chassis configuration can be composed of multiple Juniper Networks EX4200
Ethernet Switches and each member switch is running Juniper Networks Junos operating
system (Junos OS) packages. For ease of management, the Virtual Chassis configuration
provides flexible methods to upgrade software releases.
Copyright © 2010, Juniper Networks, Inc.
928
Complete Software Guide for Junos
®
OS for EX Series Ethernet Switches, Release 10.3
Summary of Contents for JUNOS OS 10.3 - SOFTWARE
Page 325: ...CHAPTER 17 Operational Mode Commands for System Setup 229 Copyright 2010 Juniper Networks Inc ...
Page 1323: ...CHAPTER 56 Operational Mode Commands for Interfaces 1227 Copyright 2010 Juniper Networks Inc ...
Page 2841: ...CHAPTER 86 Operational Commands for 802 1X 2745 Copyright 2010 Juniper Networks Inc ...
Page 3367: ...CHAPTER 113 Operational Mode Commands for CoS 3271 Copyright 2010 Juniper Networks Inc ...
Page 3435: ...CHAPTER 120 Operational Mode Commands for PoE 3339 Copyright 2010 Juniper Networks Inc ...
Page 3529: ...CHAPTER 126 Operational Mode Commands for MPLS 3433 Copyright 2010 Juniper Networks Inc ...