Example: Assigning the Virtual Chassis ID to Determine Precedence During an EX4200 Virtual Chassis Merge
There are two scenarios in which separate Virtual Chassis merge:
- A Virtual Chassis configuration that had split into two is now merging back into a single configuration because the problem that had caused it to split has been resolved.
- You merge two Virtual Chassis that had not previously been configured together.
You can explicitly assign a Virtual Chassis ID (VCID) so that, when two EX4200 Virtual Chassis configurations merge, the ID that you assigned takes precedence over the automatically assigned VCIDs and becomes the ID of the newly merged Virtual Chassis configuration.
This example shows how to assign the VCID on an EX4200 Virtual Chassis. This process is identical on an EX4500 Virtual Chassis and on a mixed EX4200 and EX4500 Virtual Chassis.
This example describes how to assign the VCID in an EX4200 Virtual Chassis configuration:
Requirements
This example uses the following hardware and software components:
- Junos OS Release 9.3 or later for EX Series switches
- Two EX4200-48P switches
- Two EX4200-24T switches
Before you begin, be sure you have:
- Installed the switches. See Mounting an EX4200 Switch.
- Cabled the switches to create the Virtual Chassis configuration. See Connecting a Virtual Chassis Cable to an EX4200 Switch.
Overview and Topology
Every Virtual Chassis configuration has a unique ID that is automatically assigned when the Virtual Chassis configuration is formed. You can also configure a Virtual Chassis ID using the set virtual-chassis id command. When two Virtual Chassis merge, the Virtual Chassis ID that you assigned takes precedence over the automatically assigned Virtual Chassis IDs and becomes the ID for the newly merged Virtual Chassis configuration.
The topology for this example consists of four switches:
- Two EX4200-24T switches
- Two EX4200-48P switches
The switches are connected as a four-member Virtual Chassis configuration and are identified as switch-A, switch-B, switch-C, and switch-D. The master is switch-A.
Configuration
To assign the Virtual Chassis ID in a Virtual Chassis configuration:
CLI Quick Configuration
To assign a Virtual Chassis ID so that when two Virtual Chassis configurations merge, the ID that you assigned takes precedence over the automatically assigned Virtual Chassis IDs and becomes the ID of the newly merged Virtual Chassis configuration, copy the following command and paste it into the terminal window:
[edit]
set virtual-chassis id
9622.6ac8.5345Step-by-Step Procedure
To assign the Virtual Chassis ID in a Virtual Chassis configuration:
- Assign the Virtual Chassis ID:
[edit]
user@switch-A# set virtual-chassis id 9622.6ac8.5345
Note: We recommend that you use the commit synchronize command to save any configuration changes that you make to a multimember Virtual Chassis configuration.
Verification
To verify that the Virtual Chassis ID has been assigned as you intended, perform these tasks:
Verifying That the Virtual Chassis ID Is Assigned
Purpose
Verify that the Virtual Chassis ID has been assigned in a Virtual Chassis configuration.
Action
Issue the show configuration virtual-chassis id command.
user@switch-A> show configuration virtual-chassis id
id 9622.6ac8.5345;
Meaning
The Virtual Chassis ID has been assigned as 9622.6ac8.5345.

