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Example: Replacing a Routing Engine in a Virtual Chassis Configuration for MX Series 5G Universal Routing Platforms

If you remove a Routing Engine from a member router in an MX Series Virtual Chassis for upgrade or repair, you must replace it with a new Routing Engine in the empty Routing Engine slot, and install the same Junos OS release on the new Routing Engine that is running on the other Routing Engines in the Virtual Chassis. The Virtual Chassis remains operational during the replacement procedure.

All four Routing Engines (both Routing Engines in the primary router and both Routing Engines in the backup router) in the Virtual Chassis must run the same Junos OS release.

Best Practice:

We recommend that you replace a Routing Engine in an MX Series Virtual Chassis configuration during a maintenance window to minimize the possibility of disruption to subscribers.

This example describes how to replace a Routing Engine in an MX Series Virtual Chassis configuration consisting of two MX Series routers, each of which has dual Routing Engines installed:

Requirements

This example uses the following software and hardware components:

  • Junos OS Release 11.4 and later releases

  • One MX240 Universal Routing Platform with dual Routing Engines

  • One MX480 Universal Routing Platform with dual Routing Engines

Note:

This configuration example has been tested using the software release listed and is assumed to work on all later releases.

See Table 1 for information about the hardware installed in each MX Series router.

Best Practice:

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

For an MX Series Virtual Chassis, the force option is the default and only behavior when you issue the commit synchronize command. Issuing the commit synchronize command for an MX Series Virtual Chassis configuration has the same effect as issuing the commit synchronize force command.

Overview and Topology

To replace a Routing Engine in an MX Series Virtual Chassis configuration, you must:

  1. Remove the Routing Engine that needs repair or upgrade.

  2. Return the Routing Engine to Juniper Networks, Inc.

  3. Install the new Routing Engine in the empty Routing Engine slot.

  4. Modify the Routing Engine factory configuration to enable formation of the Virtual Chassis.

  5. Install the same Junos OS release on the new Routing Engine that is running on the other Routing Engines in the Virtual Chassis.

  6. Reboot the new Routing Engine to run the Junos OS software release.

Topology

Figure 1 shows the topology of the MX Series Virtual Chassis configuration used in this example. This example replaces the backup RE-S-2000 Routing Engine in slot 1 of the Virtual Chassis backup router, which is an MX480 router named trefoil that is assigned member ID 1. The backup Routing Engine in slot 1 of trefoil is represented in the example as member1-re1.

For redundancy, each of the two member routers is configured with two Virtual Chassis ports.

Figure 1: Sample Topology for a Virtual Chassis with Two MX Series RoutersSample Topology for a Virtual Chassis with Two MX Series Routers

Table 1 shows the hardware and software configuration settings for each MX Series router in the Virtual Chassis.

Table 1: Components of the Sample MX Series Virtual Chassis

Router Name

Hardware

Serial Number

Member ID

Role

Virtual Chassis Ports

Network Port Slot Numbering

gladius

MX240 router with:

  • 60-Gigabit Ethernet Enhanced Queuing MPC

  • 20-port Gigabit Ethernet MIC with SFP

  • 4-port 10-Gigabit Ethernet MIC with XFP

  • Primary RE-S-2000 Routing Engine in slot 0 (represented in example as member0-re0)

  • Backup RE-S-2000 Routing Engine in slot 1 (represented in example as member0-re1)

JN10C7135AFC

0

routing-engine (primary)

vcp-2/2/0

vcp-2/3/0

FPC 0 – 11

trefoil

MX480 router with:

  • Two 30-Gigabit Ethernet Queuing MPCs

  • Two 20-port Gigabit Ethernet MICs with SFP

  • Two 2-port 10-Gigabit Ethernet MICs with XFP

  • Primary RE-S-2000 Routing Engine in slot 0 (represented in example as member1-re0)

  • Backup RE-S-2000 Routing Engine in slot 1 (represented in example as member1-re1)

JN115D117AFB

1

routing-engine (backup)

vcp-2/0/0

vcp-5/2/0

FPC 12 – 23 (offset = 12)

Configuration

To replace a Routing Engine in a Virtual Chassis configuration consisting of two MX Series routers, each with dual Routing Engines, perform these tasks:

Removing the Routing Engine

Step-by-Step Procedure

To remove the Routing Engine that needs repair or upgrade:

Returning the Routing Engine to Juniper Networks, Inc.

Step-by-Step Procedure

To return the Routing Engine to Juniper Networks, Inc:

Installing the New Routing Engine

Step-by-Step Procedure

To install the new Routing Engine in the Virtual Chassis member router:

Modifying the Routing Engine Factory Configuration

Step-by-Step Procedure

A Routing Engine shipped from the factory is loaded with a default factory configuration that includes the following stanza at the [edit] hierarchy level:

When this configuration stanza is present, the Routing Engine can operate only in a standalone chassis and not in a Virtual Chassis member router. As a result, if you install this Routing Engine in the standby slot of a Virtual Chassis member router (member1-re1 in this procedure), the Routing Engine does not automatically synchronize with the primary Routing Engine and boot in Virtual Chassis mode.

To ensure that the standby factory Routing Engine successfully synchronizes with the primary Routing Engine, you must remove the standalone chassis configuration stanza from the standby factory Routing Engine and verify that it reboots in Virtual Chassis mode before you install the Junos OS release.

To modify the Routing Engine factory configuration to ensure proper operation of the Virtual Chassis:

  1. Log in to the console of the new Routing Engine as the user root with no password.

  2. Configure a plain-text password for the root (superuser) login.

  3. Delete the standalone chassis configuration.

  4. Commit the configuration.

    The new Routing Engine synchronizes the Virtual Chassis member ID with the primary Routing Engine and boots in Virtual Chassis mode.

  5. Verify that the new Routing Engine is in Virtual Chassis mode.

    During the boot process, the router displays the following output to indicate that it has synchronized the Virtual Chassis member ID (1) with the primary Routing Engine and is in Virtual Chassis mode.

Installing the Junos OS Release on the New Routing Engine

Step-by-Step Procedure

You must install the same Junos OS release on the new Routing Engine that is running on the other Routing Engines in the MX Series Virtual Chassis. Installing the Junos OS software prepares the Routing Engine to run the new Junos OS release after a reboot. This action is also referred to as arming the Routing Engine.

To install the Junos OS release on the new Routing Engine (member1-re1) in the Virtual Chassis:

  1. Use FTP or a Web browser to download the Junos OS software to the primary Routing Engine on the Virtual Chassis primary router (member0-re0).

    See Downloading Software in the Junos OS Software Installation and Upgrade Guide.

    Note:

    Make sure you download and install the same Junos OS release that is running on all Routing Engines in the Virtual Chassis.

  2. If you have not already done so, log in to the console of the new Routing Engine as the user root with no password.

  3. If you have not already done so, configure a plain-text password for the root (superuser) login.

  4. Log in to the console of the Virtual Chassis primary router (member0-re0) as the user root.

  5. From the console of the Virtual Chassis primary router, commit the configuration.

  6. Use Telnet or SSH to log in to the member router containing the new Routing Engine (trefoil).

    Notice that the router name (trefoil) now appears in the command prompt.

  7. Install the Junos OS release on the new Routing Engine (member1-re1) from the Virtual Chassis primary router (member0-re0).

    For example:

    This command reboots member1-re1 after the software is added.

Results

After the reboot, the new Routing Engine becomes part of the Virtual Chassis, updates its command prompt to display member1-re1, and copies the appropriate configuration from the Virtual Chassis.

Verification

To verify that the MX Series Virtual Chassis is operating properly with the new Routing Engine, perform these tasks:

Verifying the Junos OS Installation on the New Routing Engine

Purpose

Verify that you have installed the correct Junos OS release on the new Routing Engine (member1-re1).

Action

Display the hostname, model name, and version information of the Junos OS release running on the new Routing Engine.

Meaning

The relevant portion of the show version local command output confirms that Junos OS Release 11.4R1-8 was installed as intended.

Verifying the Junos OS License Installation on the New Routing Engine

Purpose

Verify that the MX Virtual Chassis Redundancy Feature Pack and the required Junos OS feature licenses are properly installed on the member router containing the new Routing Engine.

For information about license installation, see:

Action

Display the Junos OS licenses installed on the new Routing Engine.

Meaning

The show system license command output confirms that the MX Virtual Chassis Redundancy Feature Pack has been installed on this member router. In addition, the necessary Junos OS feature licenses have been installed to enable use of a particular software feature or scaling level.

Switching the Local Primary Role in the Member Router to the New Routing Engine

Purpose

Verify that the MX Series Virtual Chassis is operating properly with the new Routing Engine by confirming that the new Routing Engine can take over local primary role from the existing Routing Engine in the Virtual Chassis backup router, trefoil (member 1).

Action

Switch the local primary role of the Routing Engines in trefoil from the Routing Engine in slot 0 (member1-re0) to the newly installed Routing Engine in slot 1 (member1-re1).

Wait approximately 1 minute to display the status and roles of the member routers in the Virtual Chassis after the local switchover.

Meaning

Issuing the request chassis routing-engine master switch command to initiate the local switchover of the Routing Engines in the Virtual Chassis backup router (trefoil) affects only the roles of the Routing Engines in that member router (member1-re0 and member1-re1), but does not change the global primary role of the Virtual Chassis. The output of the show virtual-chassis status command confirms that after the local switchover, member 0 (gladius) is still the Virtual Chassis primary router, and member 1 (trefoil) is still the Virtual Chassis backup router.

Before the local switchover, member1-re0 was the primary Routing Engine in the Virtual Chassis backup router (VC-Bp), and member1-re1 (the new Routing Engine) was the standby Routing Engine in the Virtual Chassis backup router (VC-Bs).

After the local switchover, member1-re0 and member1-re1 switch roles. The new Routing Engine, member1-re1, becomes the primary Routing Engine in the Virtual Chassis backup router (VC-Bp), and member1-re0 becomes the standby Routing Engine in the Virtual Chassis backup router (VC-Bs).

Table 2 lists the role transitions that occur for each member router and Routing Engine before and after the local switchover of the Routing Engines in trefoil.

Note:

The role transitions described in Table 2 apply only when you initiate the local switchover from the Virtual Chassis backup router (VC-B). For information about the role transitions that occur when you initiate the local switchover from the Virtual Chassis primary router (VC-P), see Switchover Behavior in an MX Series Virtual Chassis.

Table 2: Virtual Chassis Role Transitions Before and After Local Routing Engine Switchover

Virtual Chassis Component

Role Before Local Switchover

Role After Local Switchover

gladius (member 0)

Virtual Chassis primary router (VC-P)

Virtual Chassis primary router (VC-P)

trefoil (member 1)

Virtual Chassis backup router (VC-B)

Virtual Chassis backup router (VC-B)

member0-re0

Primary Routing Engine in the Virtual Chassis primary router (VC-Pp)

Primary Routing Engine in the Virtual Chassis primary router (VC-Pp)

member0-re1

Standby Routing Engine in the Virtual Chassis primary router (VC-Ps)

Standby Routing Engine in the Virtual Chassis primary router (VC-Ps)

member1-re0

Primary Routing Engine in the Virtual Chassis backup router (VC-Bp)

Standby Routing Engine in the Virtual Chassis backup router (VC-Bs)

member1-re1 (new Routing Engine)

Standby Routing Engine in the Virtual Chassis backup router (VC-Bs)

Primary Routing Engine in the Virtual Chassis backup router (VC-Bp)

Best Practice:

After you switch the local primary role of the Routing Engines, full synchronization of the Routing Engines takes approximately 30 minutes to complete. To prevent possible loss of subscriber state information due to incomplete synchronization, we recommend that you wait at least 30 minutes before performing another local switchover, global switchover, or graceful Routing Engine switchover in an MX Series Virtual Chassis configuration.