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Example: Configuring an EX4200 Virtual Chassis Using a Preprovisioned Configuration File

 

You can deterministically control both the role and the member ID assigned to each member switch in an EX4200 Virtual Chassis configuration by creating a preprovisioned configuration file.

A preprovisioned configuration file links the serial number of each EX4200 switch in the configuration to a specified member ID and role. The serial number must be specified in the configuration file for the member to be recognized as part of the Virtual Chassis configuration.

Note

When you use a preprovisioned configuration, you cannot modify the mastership priority or member ID of member switches through the user interfaces.

Note

After you have created a preprovisioned Virtual Chassis configuration, you can use the autoprovisioning feature to add member switches to that configuration. See Adding a New EX4200 Switch to an Existing EX4200 Virtual Chassis (CLI Procedure).

This example describes how to configure a Virtual Chassis across multiple wiring closets using a preprovisioned configuration file:

Requirements

This example uses the following hardware and software components:

  • Junos OS Release 9.0 or later for EX Series switches

  • Five EX4200-48P switches

  • Five EX4200-24T switches

  • Four XFP uplink modules

Before you create the preprovisioned configuration of the Virtual Chassis and interconnect the members across the wiring closets, be sure you have:

  1. Made a list of the serial numbers of all the switches to be connected as a Virtual Chassis configuration.
  2. Noted the desired role (routing-engine or line-card) of each switch. If you configure the member with a routing-engine role, it is eligible to function as a master or backup. If you configure the member with a line-card role , it is not eligible to become a master or backup.
  3. Installed an uplink module in each of the member switches that will be interconnected across wiring closets. See Installing an Uplink Module in an EX4200 Switch.
  4. Interconnected the member switches within each wiring closet using the dedicated VCPs on the rear panel of switches. See Connecting a Virtual Chassis Cable to an EX4200 Switch.
  5. Powered on the switch that you plan to use as the master switch (SWA-0).
  6. Run the EZSetup program on SWA-0, specifying the identification parameters. See Connecting and Configuring an EX Series Switch (CLI Procedure) for details.

    SWA-0 is going to be configured in the example to function as the master of the Virtual Chassis configuration. Thus, the properties that you specify for SWA-0 will apply to the entire Virtual Chassis configuration, including all the member switches that you specify in the preprovisioned configuration file.

  7. Configured 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/

Overview and Topology

You must select two members that you want to make eligible for election as master of the Virtual Chassis configuration. When you list these two members in the preprovisioned configuration file, you designate both members as routing-engine. One will function as the master of the Virtual Chassis configuration and the other will function as the backup.

You designate additional members, which are not eligible for election as master, as having the line-card role in the preprovisioned configuration file.

In this example, five EX4200 switches (SWA-0 through SWA-4) are interconnected with their dedicated VCPs in wiring closet A and five EX4200 switches (SWA-5 through SWA-9) are interconnected with their dedicated VCPs in wiring closet B.

SWA-0 (in wiring closet A) is going to be the master of the Virtual Chassis configuration. This example shows how to create a preprovisioned configuration file on SWA-0 for all member switches that will be interconnected in the Virtual Chassis configuration. The preprovisioned configuration file includes member IDs for the members in wiring closet A and for the members in wiring closet B.

SWA-5 (in wiring closet B) is going to be the backup of the Virtual Chassis configuration. Both SWA-0 and SWA-5 are specified in the preprovisioned configuration file with the role of routing-engine. All other members are specified with the role of line-card.

If all member switches could be interconnected with their dedicated VCPs, you could simply power on the switches after saving and committing the preprovisioned configuration file. The master detects the connection of the members through the dedicated VCPs and applies the parameters specified in the preprovisioned configuration file.

However, the Virtual Chassis cables that interconnect the VCPs of member switches within a single wiring closet are not long enough to connect member switches across wiring closets. Instead, you can configure the uplink module ports or the SFP networks ports on EX4200-24F switches as VCPs to interconnect the member switches in wiring closet A to the member switch in wiring closet B. For redundancy, this example connects uplink VCPs from two member switches in wiring closet A (SWA–0 and SWA–2) to two member switches (SWA-5 and SWA-7) in wiring closet B.

Note

You can use interfaces on SFP, SFP+, and XFP uplink modules and the SFP network ports on EX4200-24F switches as VCPs. When an uplink module port or SFP network port is set as a VCP, it cannot be used for any other purpose. The SFP uplink module has four 1-Gbps ports; the SFP+ uplink module has four 1-Gbps or two 10-Gbps ports; the XFP uplink module has two 10-Gbps ports. The uplink module ports that are not set as VCPs can be configured as trunk ports to connect to a distribution switch.

Because this particular preprovisioned configuration is for a Virtual Chassis that is interconnected across wiring closets, we will bring up the Virtual Chassis configuration in stages. First, we power on SWA-0 (without powering on any other switches) and create the preprovisioned configuration file. Then we power on the remaining switches in wiring closet A. If we check the status of the Virtual Chassis configuration at this point by using the show virtual-chassis command, it will display only member 0 through member 4. The members that have not yet been interconnected will not be listed.

Next power on SWA-5 without powering on the remaining switches (SWA-6 through SWA-9) in wiring closet B. Bring up SWA-5 as a standalone switch and set one of its uplinks as a VCP prior to interconnecting it with the Virtual Chassis configuration in wiring closet A. Without this setting, SWA-5 cannot be detected as a member switch by the master of the Virtual Chassis configuration.

You can set the uplink VCP of SWA-5 without running the EZSetup program by directly connecting to the console port. If you wish, you can run the EZSetup program and specify identification parameters. When you interconnect SWA-5 with the master of the Virtual Chassis configuration, the master overwrites any conflicting parameters.

After setting the VCP in SWA-5, connect this VCP with the VCP of SWA-0 in wiring closet A. SWA-5 (serial number pqr678) is specified as a routing-engine in the preprovisioned configuration file.

This example uses SWA-5 as the backup of the Virtual Chassis configuration. If a problem occurred in wiring closet A, SWA-5 would take control of the Virtual Chassis configuration and maintain the network connections. Specify both SWA-0 and SWA-5 as routing-engine. Because SWA-0 is powered on prior to SWA-5, it has additional prioritization properties that cause it to be elected as master of the Virtual Chassis configuration.

After being physically interconnected with SWA-0, SWA-5 reboots and comes up as member 5 and as the backup of the Virtual Chassis configuration.

Power on the remaining switches (SWA-6 through SWA-9) in wiring closet B. The master can now detect that all members are present. Finally, for redundancy, configure an additional VCP on SWA-7 through the master.

The topology for this example consists of:

  • Three EX4200-48P switches (SWA-0 , SWA-2, and SWA-4) in wiring closet A.

  • Two EX4200-48P switches (SWA-5 and SWA-9) in wiring closet B.

  • Two EX4200-24T switches (SWA-1 and SWA-3) in wiring closet A.

  • Three EX4200-24T switches (SWA-6, SWA-7, and SWA-8) in wiring closet B.

  • Four XFP uplink modules. Two are installed in wiring closet A and two are installed in wiring closet B.

Table 1 shows the Virtual Chassis configuration settings for a preprovisioned Virtual Chassis composed of member switches in different wiring closets.

Table 1: Components of a Preprovisioned EX4200 Virtual Chassis Interconnected Across Multiple Wiring Closets

SwitchSerial numberMember IDRole Uplink Module PortsHardwareLocation

SWA-0

abc123

0

routing-engine

xe-0/1/0

EX4200-48P and XFP uplink module

Wiring closet A

SWA-1

def456

1

linecard

 

EX4200-24T

Wiring closet A

SWA-2

ghi789

2

linecard

xe-2/1/0

EX4200-48P and XFP uplink module

Wiring closet A

SWA-3

jkl012

3

linecard

 

EX4200-24T

Wiring closet A

SWA-4

mno345

4

linecard

 

EX4200-48P

Wiring closet A

SWA-5

pqr678

5

routing-engine

xe-0/1/0

Note: The member ID of SWA-5 is 0 at the time that its uplink module port is configured as a VCP.

EX4200-48P and XFP uplink module

Wiring closet B

SWA-6

stu901

6

linecard

 

EX4200-24T

Wiring closet B

SWA-7

vwx234

7

linecard

xe-7/1/0

EX4200-24T and XFP uplink module

Wiring closet B

SWA-8

yza567

8

linecard

 

EX4200-24T

Wiring closet B

SWA-9

bcd890

9

linecard

 

EX4200-48P

Wiring closet B

Figure 1 shows the different types of interconnections used for this Virtual Chassis configuration. The rear view shows that the member switches within each wiring closet are interconnected to each other using the dedicated VCPs. The front view shows that the uplink module ports that have been set as VCPs and interconnected across the wiring closets. The uplink module ports that are not set as VCPs can be configured as trunk ports to connect to a distribution switch.

Note

The interconnections shown in Figure 1 are the same as they would be for a configuration that was not preprovisioned across wiring closets.

Figure 1: Maximum Size EX4200 Virtual Chassis Interconnected Across Wiring Closets
Maximum Size
EX4200 Virtual Chassis Interconnected Across Wiring Closets

Configuration

To configure the Virtual Chassis across multiple wiring closets using a preprovisioned configuration, perform this task:

Note

We recommend that you use the commit synchronize command to save any configuration changes that you make to a multimember Virtual Chassis configuration.

Step-by-Step Procedure

To create a preprovisioned configuration for the Virtual Chassis:

  1. Specify the preprovisioned configuration mode:
    [edit virtual-chassis]

    user@SWA–0# set preprovisioned

  2. Specify all the members that will be included in the Virtual Chassis configuration, listing each switch's serial number with the desired member ID and the desired role:
    [edit virtual-chassis]

    user@SWA–0# set member 0 serial-number abc123 role routing-engine

    user@SWA–0# set member 1 serial-number def456 role line-card

    user@SWA–0# set member 2 serial-number ghi789 role line-card

    user@SWA–0# set member 3 serial-number jkl012 role line-card

    user@SWA–0# set member 4 serial-number mno345 role line-card

    user@SWA–0# set member 5 serial-number pqr678 role routing-engine

    user@SWA–0# set member 6 serial-number stu901 role line-card

    user@SWA–0# set member 7 serial-number vwx234 role line-card

    user@SWA-0# set member 8 serial-number yza567 role line-card

    user@SWA–0# set member 9 serial-number bcd890 role line-card
  3. Power on the member switches in wiring closet A.
  4. Prepare the members in wiring closet A for interconnecting with the member switches in wiring closet B by setting uplink VCPs for member 0 and member 2:
    user@SWA-0> request virtual-chassis vc-port (Dedicated VCP) set pic-slot 1 port 0

    user@SWA-2> request virtual-chassis vc-port set pic-slot 1 port 0 member 2
    Note
    • For redundancy, this example sets an uplink VCP in both SWA-0 and SWA-2.

    • This example omits the specification of the member 0 in setting the uplink for SWA-0. The command applies by default to the switch where it is executed.

  5. Power on SWA-5 and connect to it. This switch comes up as member ID 0 and functions as master of itself. Although SWA-5 is listed in the preprovisioned configuration file, it is not a present member of the Virtual Chassis configuration that has been powered on thus far. In order for the master to detect SWA-5 as a connected member, you must first set an uplink VCP on SWA-5 and interconnect that VCP with the uplink VCP of SWA-0.
  6. Set the first uplink of SWA-5 to function as a VCP. Because SWA-5 has been powered on as a separate switch and is still operating independently at this point, its member ID is 0.
    user@SWA-5> request virtual-chassis vc-port set pic-slot 1 port 0
    Note

    This example omits the specification of the member 0 in configuring the uplink for SWA-5 (at this point the member ID of SWA-5 is still 0). The command applies by default to the switch where it is executed.

  7. Power off SWA-5 and connect the fiber cable from SWA-5 uplink VCP xe-0/1/0 to the uplink VCP xe-0/1/0 on SWA-0.
  8. Power on SWA-5.
  9. Now that SWA-5 has been brought up as member 5 of the Virtual Chassis configuration, power on the remaining switches (SWA-6 through SWA-9) in wiring closet B. They are interconnected with SWA-5 using the dedicated VCPs on the rear panel and are therefore detected by the master as interconnected members. If you check the status of the Virtual Chassis configuration at this point, all the members that were specified in the preprovisioned configuration file should be displayed as present. Additional configuration for member switches can now be done through the master switch.
  10. Set one uplink module port of SWA-7 to function as a VCP:
    user@SWA-0> request virtual-chassis vc-port set pic-slot 1 port 0

    member 7


Results

Display the results of the configuration on SWA-0:

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 the member IDs and roles are all set as expected.

Action

Display the members of the Virtual Chassis configuration:

Meaning

The output shows that all members listed in the preprovisioned configuration file are connected to the Virtual Chassis configuration. It confirms that SWA-0 (member 0) is functioning as the master of the Virtual Chassis configuration. The other switch configured with the routing-engine role (SWA-5) is functioning as the backup. The Neighbor List displays the interconnections of the member VCPs.

Verifying That the Dedicated VCPs and Uplink VCPs Are Operational

Purpose

Verify that the dedicated VCPs interconnecting the member switches within each wiring closet and the uplink module VCPs interconnecting the member switches across wiring closets are operational.

Action

Display the VCP interfaces:

user@SWA-0> show virtual-chassis vc-port all-members

Meaning

The dedicated VCPs interconnecting the member switches within wiring closets are displayed as vcp-0 and vcp-1. The uplink module VCPs interconnecting member switches (members 0, 2, 5, and 7) across wiring closets are displayed as 1/0 and 1/1 and identified as Configured.

Troubleshooting

To troubleshoot a preprovisioned Virtual Chassis configuration that is interconnected across wiring closets, perform these tasks:

Troubleshooting Nonoperational VCPs

Problem

A VCP shows a status of down.

Solution

Check the cable to make sure that it is properly and securely connected to the ports.