Mastership Priority; Mixed Virtual Chassis - Juniper EX9200 Features Manual

Virtual Chassis Feature Guide for EX9200 Switches

Mastership Priority

Mixed Virtual Chassis

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In a configuration that is not preprovisioned, you can designate the role (master, backup,
or linecard) that a member switch assumes by configuring its mastership priority (from
0 through 255 ). The mastership priority value is the factor in the master election algorithm
with the highest precedence for selecting the master of the Virtual Chassis configuration.
A switch with a mastership priority of
The default value for mastership priority is
EX4550, and EX4600 switches. When a standalone switch is powered on, it receives the
default mastership priority value. Because it is the only member of the Virtual Chassis
configuration, it is also the master. When you interconnect a standalone switch to an
existing Virtual Chassis configuration (which implicitly includes its own master), we
recommend that you explicitly configure the mastership priority of the members that
you want to function as the master and backup.
NOTE: Configuring the same mastership priority value for both the master
and backup helps to ensure a smooth transition from master to backup when
the master becomes unavailable. It prevents the original master from
preempting control from the backup when the backup has taken control of
the Virtual Chassis configuration because the original master became
unavailable.
In a preprovisioned configuration, you assign the role of each member switch. An EX9200
switch does not have a mastership priority and an EX9200 Virtual Chassis, therefore,
must be preprovisioned.
EX4200 switches, EX4500 switches, and EX4550 switches can be interconnected into
the same Virtual Chassis to form a mixed EX4200 and EX4500 Virtual Chassis, mixed
EX4200 and EX4550 Virtual Chassis, mixed EX4500 and EX4550 Virtual Chassis, or
mixed EX4200, EX4500, and EX4550 Virtual Chassis. The mixed Virtual Chassis supports
up to 10 member switches regardless of whether the switches are EX4200 switches,
EX4500 switches, or EX4550 switches. Any model of EX4200, EX4500, or EX4550
switch can be interconnected into the same mixed Virtual Chassis. The master election
process that decides member switch roles in a mixed Virtual Chassis is identical to the
master election process in a non-mixed Virtual Chassis, so any member switch in a mixed
Virtual Chassis can assume the master, backup, or linecard role.
EX4300 and EX4600 switches can act as member switches in a mixed EX4300 and
EX4600 Virtual Chassis. An EX4600 switch must assume the master role in a mixed
EX4300 and EX4600 Virtual Chassis. We strongly recommend configuring EX4600
switches only into the Routing Engine role when you are configuring a mixed EX4300
and EX4600 Virtual Chassis to ensure only EX4600 switches assume the master role.
EX2200, EX2300, EX3300, and EX3400 switches cannot be a part of any mixed Virtual
Chassis.
never assumes the backup or master role.
0
128 for EX2200, EX3300, EX4200, EX4500,
Copyright © 2017, Juniper Networks, Inc.