Understanding Split And Merge In A Virtual Chassis Configuration - Juniper JUNOS OS 10.3 - SOFTWARE Manual

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Understanding Split and Merge in a Virtual Chassis Configuration

What Happens When a Virtual Chassis Configuration Splits
942
®
OS for EX Series Ethernet Switches, Release 10.3
Understanding Virtual Chassis Configuration on page 934
Example: Configuring Fast Failover on Uplink Module VCPs to Reroute Traffic When a
Virtual Chassis Member Switch or Intermember Link Fails on page 993
Setting an Uplink Module Port as a Virtual Chassis Port (CLI Procedure) on page 1023
In a Virtual Chassis configuration, two or more Juniper Networks EX4200 Ethernet
Switches are connected together to form a unit that is managed as a single chassis. If
there is a disruption to the Virtual Chassis configuration due to member switches failing
or being removed from the configuration, the Virtual Chassis configuration splits into two
separate Virtual Chassis. This situation could cause disruptions in the network if the two
separate configurations share common resources, such as global IP addresses. The split
and merge feature provides a method to prevent the separate Virtual Chassis
configurations from adversely affecting the network and also allows the two parts to
merge back into a single Virtual Chassis configuration.
NOTE: If a Virtual Chassis configuration splits into separate parts, we
recommend that you resolve the problem that caused the Virtual Chassis
configuration to split as soon as possible.
You can also use this feature to merge two active but separate Virtual Chassis that have
not previously been part of the same configuration into one Virtual Chassis configuration.
NOTE: The split and merge feature is enabled by default on EX4200 switches.
You can disable the split and merge feature by using the
no-split-detection
This topic describes:
What Happens When a Virtual Chassis Configuration Splits on page 942
Merging Virtual Chassis Configurations on page 943
When a Virtual Chassis configuration splits into two separate Virtual Chassis
configurations, the individual member switches detect this topology change and run the
master election algorithm to select a new master for each of the two Virtual Chassis
configurations. The new masters then determine whether their Virtual Chassis
configuration remains active. One of the configurations remains active based on the
following:
command.
Copyright © 2010, Juniper Networks, Inc.
set virtual-chassis