Backup Role; Linecard Role - Juniper EX9200 Features Manual

Virtual Chassis Feature Guide for EX9200 Switches

Backup Role

Linecard Role

20
In a preprovisioned configuration, one of the two members assigned as
functions as the master member. The selection of which member assigned as
functions as master and which as backup is determined by the software
routing-engine
based on the master election algorithm. See Understanding How the Master in a Virtual
Chassis Is Elected.
In a configuration that is not preprovisioned, the selection of the master and backup
is determined by the mastership priority value and secondary factors in the master
election algorithm.
In a mixed EX4300 and EX4600 Virtual Chassis, an EX4600 switch must assume the
master role.
In any mixed Virtual Chassis configuration that includes EX4200 switches, EX4500
switches, or EX4550 switches, any switch can be configured in any role in any
configuration.
The member that functions in the backup role in the Virtual Chassis:
Maintains a state of readiness to take over the master role if the master fails.
Runs Junos OS for EX Series switches in a backup role.
Synchronizes with the master in terms of protocol states, forwarding tables, and so
forth, so that it is prepared to preserve routing information and maintain network
connectivity without disruption in case the master is unavailable.
You must have at least two member switches in the Virtual Chassis configuration in order
to have a backup member.
In a preprovisioned configuration, one of the two members assigned as
functions in the backup role. The selection of which member assigned as
functions as master and which as backup is determined by the software based on the
master election algorithm. See Understanding How the Master in a Virtual Chassis Is
Elected.
In a configuration that is not preprovisioned, the selection of the master and backup
is determined by the mastership priority value and secondary factors in the master
election algorithm.
In a mixed EX4300 and EX4600 Virtual Chassis, we strongly recommend configuring an
EX4600 switch into the backup role. A mixed EX4300 and EX4600 Virtual Chassis must
use an EX4600 member switch in the master role, and configuring an EX4600 switch
into the backup role ensures that the Virtual Chassis remains up after a switchover event.
In any mixed Virtual Chassis configuration that includes EX4200 switches, EX4500
switches, or EX4550 switches, any switch can be configured in any role in any
configuration.
A member that functions in the linecard role in the Virtual Chassis:
routing-engine
routing-engine
routing-engine
Copyright © 2017, Juniper Networks, Inc.