Related
Documentation
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
Understanding Split and Merge in a Virtual Chassis Configuration
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 set virtual-chassis
no-split-detection
command.
This topic describes:
•
What Happens When a Virtual Chassis Configuration Splits on page 942
•
Merging Virtual Chassis Configurations on page 943
What Happens When a Virtual Chassis Configuration Splits
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:
Copyright © 2010, Juniper Networks, Inc.
942
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 ...