Example: Setting Up a Multimember EX4200 Virtual Chassis Access Switch with a Default Configuration
You can configure a multimember EX4200 Virtual Chassis access switch in a single wiring closet without setting any parameters—by simply cabling the switches together, using the dedicated Virtual Chassis ports (VCPs). You do not need to modify the default configuration to enable these ports. They are operational by default. The Virtual Chassis configuration automatically assigns the primary, backup, and linecard roles, based on the sequence in which the switches are powered on and other factors in the primary-role election algorithm.
We recommend that you explicitly configure the primary-role priority of the switches to ensure that the switches continue to perform the desired roles when additional switches are added or other changes occur. However, it is possible to use the default configuration described in this example.
This example describes how to configure a multimember Virtual Chassis in a single wiring closet, using the default role assignments:
Requirements
This example uses the following hardware and software components:
Junos OS Release 9.0 or later for EX Series switches
Two EX4200-48P switches
Four EX4200-24P switches
Overview and Topology
A Virtual Chassis configuration is easily expandable. This example shows a Virtual Chassis configuration composed of six EX4200 switches. It provides networking access for 180 onsite workers, who are sitting within range of a single wiring closet. The six combined switches are identified by a single host name and managed through a global management IP address.
To set up a multimember Virtual Chassis configuration within a single wiring closet, you need to run the EZSetup program only once. Connect to the primary and run EZSetup to specify its identification, time zone, and network properties. When additional switches are connected through the Virtual Chassis ports (VCPs), they automatically receive the same properties that were specified for the primary.
Topology
The topology for this example (see Figure 1) consists of six switches:
Two EX4200-48P switches (SWA-0 and SWA-1) with 48 access ports, all of which support Power over Ethernet (PoE)
Four EX4200-24P switches (SWA-2, SWA-3, SWA-4, and SWA-5) with 24 access ports, all of which support PoE
Figure 1 shows that all the member switches are interconnected with the dedicated VCPs on the rear panel. The LCD on the front displays the member ID and role.
Configuration
To configure a multimember Virtual Chassis access switch in a single wiring closet using the factory defaults, perform this task:
Procedure
Step-by-Step Procedure
To configure a multimember Virtual Chassis with default role assignments:
Make sure the dedicated VCPs on the rear panel are properly cabled. See Virtual Chassis Cabling Configuration Examples for EX4200 Switches for additional information.
Power on the switch that you want to function as the primary (SWA-0). This examples uses one of the larger switches (EX4200-48P) as the primary.
Check the front panel LCD to confirm that the switch has powered on correctly and that a member ID has been assigned.
Run the EZSetup program on SWA-0, the primary, specifying the identification parameters. See Connecting and Configuring an EX Series Switch (CLI Procedure) for details.
Configure SWA-0 with the virtual management Ethernet (VME) interface for out-of-band management of the Virtual Chassis configuration, if desired.
[edit] user@SWA-0# set interfaces vme unit 0 family inet address /ip-address/mask/
After a lapse of at least one minute, power on SWA-1. This example uses the second EX4200-48P switch as the backup.
Check the front panel LCD to confirm that the switch has powered on correctly and that a member ID has been assigned.
Power on SWA-2, and check the front panels to make sure that the switch is operating correctly.
Continue to power on the member switches one by one, checking the front panels as you proceed.
Verification
To confirm that the configuration is working properly, perform these tasks:
Verifying the Member IDs and Roles of the Member Switches
Purpose
Verify that all the interconnected member switches are included within the Virtual Chassis configuration and that their roles are assigned appropriately.
Action
Display the members of the Virtual Chassis configuration:
user@SWA-0> show virtual-chassis
Virtual Chassis ID: 0000.e255.00e0
Mastership Neighbor List
Member ID Status Serial No Model Priority Role ID Interface
0 (FPC 0) Prsnt abc123 ex4200-48p 128 Master* 1 vcp-0
5 vcp-1
1 (FPC 1) Prsnt def123 ex4200-48p 128 Backup 2 vcp-0
0 vcp-1
2 (FPC 2) Prsnt abd231 ex4200-24p 128 Linecard 3 vcp-0
1 vcp-1
3 (FPC 3) Prsnt cab123 ex4200-24p 128 Linecard 4 vcp-0
2 vcp-1
4 (FPC 4) Prsnt fed456 ex4200-24p 128 Linecard 5 vcp-0
3 vcp-1
5 (FPC 5) Prsnt jkl231 ex4200-24p 128 Linecard 0 vcp-0
4 vcp-1Meaning
The show virtual-chassis command lists the
member switches of the Virtual Chassis configuration with the member
IDs and primary-role priority values. It also displays the neighbor
members with which each member is interconnected. The fpc number is the same as the member ID.
Verifying That the VCPs Are Operational
Purpose
Verify that the dedicated VCPs interconnecting the member switches are operational.
Action
Display the VCP interfaces.
user@SWA-0> show virtual-chassis vc-port all-members fpc0: -------------------------------------------------------------------------- Interface Type Status or PIC / Port vcp-0 Dedicated Up vcp-1 Dedicated Up fpc1: -------------------------------------------------------------------------- Interface Type Status or PIC / Port vcp-0 Dedicated Up vcp-1 Dedicated Up fpc2: -------------------------------------------------------------------------- Interface Type Status or PIC / Port vcp-0 Dedicated Up vcp-1 Dedicated Up fpc3: -------------------------------------------------------------------------- Interface Type Status or PIC / Port vcp-0 Dedicated Up vcp-1 Dedicated Up fpc4: -------------------------------------------------------------------------- Interface Type Status or PIC / Port vcp-0 Dedicated Up vcp-1 Dedicated Up fpc5: Interface Type Status or PIC / Port vcp-0 Dedicated Up vcp-1 Dedicated Up
Meaning
The show virtual-chassis vc-port all-members command lists the VCP interfaces that are enabled for the member
switches of the Virtual Chassis configuration and shows the status
of the interfaces. In this case, no VCP uplinks have been configured.
However, the VCP interfaces are automatically configured and enabled
when you interconnect member switches using the dedicated VCPs. The
dedicated VCP interfaces are identified simply as vcp-0 and vcp-1.
They do not use the standard interface address (in which the member
ID is represented by the first digit). The output in this example
shows that all interfaces are operational. The fpc number
is the same as the member ID.
Troubleshooting
To troubleshoot the configuration of a multimember Virtual Chassis in a single wiring closet, perform these tasks:
Troubleshooting Primary-role Priority
Problem
You want to explicitly designate one member as the primary and another as backup.
Solution
Change the primary-role priority value of the member that you want to function as primary, assigning the highest primary-role priority value to that member.
These configuration changes are made through the current primary, SWA-0.
Configure primary-role priority of member 0 to be the highest possible value.
[edit virtual-chassis] user@SWA-0# set member 0 mastership-priority 255
Set the primary-role priority of another member that you want to function as the backup member as the same value:
[edit virtual-chassis] user@SWA-0# set member 2 mastership-priority 255