Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

Example: Configuring Interchassis Redundancy for MX Series Routers Using a Virtual Chassis

 

To provide interchassis redundancy for MX Series 3D Universal Edge Routers, you can configure a Virtual Chassis. A Virtual Chassis configuration interconnects two MX Series routers into a logical system that you can manage as a single network element. The member routers in a Virtual Chassis are interconnected by means of Virtual Chassis ports that you configure on Modular Port Concentrator/Modular Interface Card (MPC/MIC) interfaces (network ports) on each MX Series router.

This example describes how to set up and configure a Virtual Chassis consisting of two MX Series routers:

Requirements

This example uses the following software and hardware components:

  • Junos OS Release 11.2 and later releases

  • One MX240 3D Universal Edge Router

  • One MX480 3D Universal Edge Router

Note

This configuration example has been tested using Junos OS Release 11.2 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 throughout this procedure 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 configure the Virtual Chassis shown in this example, you must create a preprovisioned configuration at the [edit virtual-chassis] hierarchy level on the router to be designated as the protocol primary of the Virtual Chassis. The preprovisioned configuration includes the serial number, member ID, and role for each member router (also known as member chassis) in the Virtual Chassis. When a new member router joins the Virtual Chassis, the software compares its serial number against the values specified in the preprovisioned configuration. If the serial number of a joining router does not match any of the configured serial numbers, the software prevents that router from becoming a member of the Virtual Chassis.

After you commit the preprovisioned configuration on the primary router, you must assign the preprovisioned member IDs by issuing the request virtual-chassis member-id set operational mode command on each router, which causes the router to reboot. When the reboot is complete, you create one or more Virtual Chassis ports by issuing the request virtual-chassis vc-port set operational mode command on each router. The Virtual Chassis forms when the line cards in both member routers are back online.

This example configures a Virtual Chassis that interconnects two MX Series routers, and uses the basic topology shown in Figure 1. For redundancy, two Virtual Chassis ports are configured on each member router.

Figure 1: Sample Topology for a Virtual Chassis with Two MX Series Routers
Sample
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. You use some of these settings in the preprovisioned configuration and when you assign the member IDs and create the Virtual Chassis ports.

Note

MX Series Enhanced Queuing IP Services DPCs (DPCE-R-Q model numbers) and MX Series Enhanced Queuing Ethernet Services DPCs (DPCE-X-Q model numbers) do not interoperate with features of the MX Series Virtual Chassis. If any MX Series Enhanced Queuing DPCs are installed in a router to be configured as a member of a Virtual Chassis, you must ensure that these DPCs are offline before you configure 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 configure a Virtual Chassis consisting of two MX Series routers, perform these tasks:

Preparing to Configure the Virtual Chassis

Step-by-Step Procedure

To prepare for configuring an MX Series Virtual Chassis:

  1. Make a list of the serial numbers of both routers that you want to configure as part of the Virtual Chassis.

    The chassis serial number is located on a label affixed to the side of the MX Series chassis. Alternatively, you can obtain the chassis serial number by issuing the show chassis hardware command, which is especially useful if you are accessing the router from a remote location. For example:

    user@gladius> show chassis hardware
  2. Note the desired role (routing-engine) for each router in the Virtual Chassis.

    In a two-router Virtual Chassis configuration, you must designate each router with the routing-engine role, which enables either router to function as the primary or backup of the Virtual Chassis.

    • The primary router maintains the global configuration and state information for all members of the Virtual Chassis, and runs the chassis management processes.

    • The backup router synchronizes with the primary router and relays chassis control information (such as linecard presence and alarms) to the primary router. If the primary router is unavailable, the backup router takes primary role of the Virtual Chassis to preserve routing information and maintain network connectivity without disruption.

  3. Note the member ID (0 or 1) to be assigned to each router in the Virtual Chassis.

    In this example, the primary router is assigned member ID 0, and the backup router is assigned member ID 1.

  4. Ensure that both MX Series routers in the Virtual Chassis have dual Routing Engines installed, and that all four Routing Engines in the Virtual Chassis are the same model.

    For example, you cannot configure a Virtual Chassis if one member router has RE-S-2000 Routing Engines installed and the other member router has RE-S-1800 Routing Engines installed.

  5. Ensure that the necessary Modular Port Concentrator/Modular Interface Card (MPC/MIC) interfaces on which to configure the Virtual Chassis ports are installed and operational in each member router.Note

    An MX Series Virtual Chassis does not support a combination of 1-Gigabit Ethernet (ge media type) Virtual Chassis ports and 10-Gigabit Ethernet (xe media type) Virtual Chassis ports within the same Virtual Chassis. You must configure either all 10-Gigabit Ethernet Virtual Chassis ports or all 1-Gigabit Ethernet Virtual Chassis ports in the same Virtual Chassis. We recommend that you configure Virtual Chassis ports on 10-Gigabit Ethernet interfaces. This restriction has no effect on access ports or uplink ports in an MX Series Virtual Chassis configuration.

  6. If MX Series Enhanced Queuing IP Services DPCs (DPCE-R-Q model numbers) or MX Series Enhanced Queuing Ethernet Services DPCs (DPCE-X-Q model numbers) are installed in a router to be configured as a member of the Virtual Chassis, make sure that these DPCs are offline before you configure the Virtual Chassis.

    Otherwise, the MX Series Virtual Chassis configuration will not function.Note

    MX Series Enhanced Queuing IP Services DPCs (DPCE-R-Q model numbers) and MX Series Enhanced Queuing Ethernet Services DPCs (DPCE-X-Q model numbers) do not interoperate with features of the MX Series Virtual Chassis.

  7. Determine the desired location of the dedicated Virtual Chassis ports on both member routers, and use the Virtual Chassis ports to physically interconnect the member routers in a point-to-point topology.
  8. Ensure that both MX Series routers to be configured as members of the Virtual Chassis are running the same Junos OS release, and have basic network connectivity.
  9. Install the MX Virtual Chassis Redundancy Feature Pack license on each router to be configured as part of the Virtual Chassis.
  10. Install the necessary Junos OS feature licenses on each router to be configured as part of the Virtual Chassis.

Creating and Applying Configuration Groups for the Virtual Chassis

Step-by-Step Procedure

For a Virtual Chassis configuration consisting of two MX Series routers, each of which supports dual Routing Engines, you must create and apply the following configuration groups on the router to be designated as the primary of the Virtual Chassis instead of using the standard re0 and re1 configuration groups:

  • member0-re0

  • member0-re1

  • member1-re0

  • member1-re1

Note

The membern-ren naming format for configuration groups is reserved for exclusive use by member routers in an MX Series Virtual Chassis configuration.

To create and apply configuration group information for the Virtual Chassis:

  1. Log in to the console on member 0 (gladius).
  2. In the console window on member 0, create and apply the member0-re0 configuration group.
  3. Delete the standard re0 configuration group from the global configuration on member 0.
  4. Create and apply the member0-re1 configuration group on member 0.
  5. Delete the standard re1 configuration group from the global configuration on member 0.
  6. Create and apply the member1-re0 configuration information on member 0.

    The examples in Steps 6 and 7 set the IP address for the fxp0 management interface and add an IP route for it in the event that routing becomes inactive.

  7. Create and apply the member1-re1 configuration information on member 0.
  8. Commit the configuration on member 0.

Results

Display the results of the configuration.

Configuring Preprovisioned Member Information for the Virtual Chassis

Step-by-Step Procedure

To configure the preprovisioned member information on member 0 (gladius):

  1. Log in to the console on member 0.
  2. Specify that you want to create a preprovisioned Virtual Chassis configuration.
  3. Configure the member ID (0 or 1), role (routing-engine), and chassis serial number for each member router in the Virtual Chassis.
  4. Disable detection of a split in the Virtual Chassis configuration.

    By default, split detection in an MX Series Virtual Chassis is enabled.
    Best Practice

    We recommend that you disable split detection for a two-member MX Series Virtual Chassis configuration if you think the backup router is more likely to fail than the Virtual Chassis port links to the backup router. Configuring redundant Virtual Chassis ports on different line cards in each member router reduces the likelihood that all Virtual Chassis port links to the backup router will fail.

  5. (Optional) Enable tracing of Virtual Chassis operations.
  6. Commit the configuration.

Results

Display the results of the configuration.

Configuring Enhanced IP Network Services

Step-by-Step Procedure

For an MX Series Virtual Chassis to function properly, you must configure enhanced IP network services on both member routers (member 0 and member 1) when you first set up the Virtual Chassis. Enhanced IP network services define how the chassis recognizes and uses certain modules. When you set each member router’s network services to enhanced-ip, only MPC/MIC modules and MS-DPC modules are powered on in the chassis. Nonservice DPCs do not work with enhanced IP network services.

To configure enhanced IP network services for a Virtual Chassis:

  1. Configure enhanced IP network services on member 0 (gladius).
    1. Log in to the console on member 0.

    2. Access the chassis hierarchy.

    3. Configure enhanced IP network services for member 0.

    4. Commit the configuration on member 0.

      Note

      Immediately after you commit the configuration, the software prompts you to reboot the router. You can proceed without rebooting the router at this point because a reboot occurs when you configure the member IDs to enable Virtual Chassis mode, later in this procedure.

  2. Configure enhanced IP network services on member 1 (trefoil).
    1. Log in to the console on member 1.

    2. Access the chassis hierarchy.

    3. Configure enhanced IP network services for member 1.

    4. Commit the configuration on member 1.

      Note

      Immediately after you commit the configuration, the software prompts you to reboot the router. You can proceed without rebooting the router at this point because a reboot occurs when you configure the member IDs to enable Virtual Chassis mode, later in this procedure.

Enabling Graceful Routing Engine Switchover and Nonstop Active Routing

Step-by-Step Procedure

Before you configure member IDs and Virtual Chassis ports, you must enable graceful Routing Engine switchover (GRES) and nonstop active routing (NSR) on both member routers in the Virtual Chassis.

To enable GRES and NSR:

  1. Enable GRES and NSR on member 0 (gladius):
    1. Log in to the console on member 0.

    2. Enable graceful switchover.

    3. Enable nonstop active routing.

    4. Configure the commit command to automatically result in a commit synchronize action between the dual Routing Engines in member 0.

    5. Commit the configuration.

  2. Enable GRES and NSR on member 1 (trefoil):
    1. Log in to the console on member 1.

    2. Enable graceful switchover.

    3. Enable nonstop active routing.

    4. Configure the commit command to automatically result in a commit synchronize action between the dual Routing Engines in member 1.

    5. Commit the configuration.

    Note

    When you configure nonstop active routing, you must include the commit synchronize statement at the [edit system] hierarchy level. Otherwise, the commit operation fails.

    For an MX Series Virtual Chassis, the force option is the default and only behavior when you use the commit synchronize statement. Including the commit synchronize statement for an MX Series Virtual Chassis configuration has the same effect as including the commit synchronize force statement.

Configuring Member IDs and Rebooting the Routers to Enable Virtual Chassis Mode

Step-by-Step Procedure

To configure (set) the preprovisioned member ID for each MX Series router in the Virtual Chassis, use the request virtual-chassis member-id set command. Assigning the member ID causes the router to reboot in preparation for forming the Virtual Chassis.

Note

If you issue the request virtual-chassis member-id set command without first installing an MX Virtual Chassis Redundancy Feature Pack license on both member routers, the software displays a warning message that you are operating without a valid Virtual Chassis software license.

To configure the member ID and reboot each router to enable Virtual Chassis mode:

  1. Log in to the console on member 0 (gladius).
  2. Set the member ID on member 0.

    The router reboots in preparation for membership in the Virtual Chassis. After the reboot, all MPCs remain powered off until the Virtual Chassis port connection is configured.

  3. Log in to the console on member 1 (trefoil).
  4. Set the member ID on member 1.

    After the reboot, all MPCs remain powered off until the Virtual Chassis port connection is configured.

Results

Display the results of the configuration on each router. At this point in the procedure, all line cards are offline, and the routers are each designated with the Master role because they are not yet interconnected as a fully formed Virtual Chassis. In addition, member 1 (trefoil) remains in Amnesiac state (has no defined configuration) until the Virtual Chassis forms and you commit the configuration.

For member 0 (gladius):

user@gladius> show virtual-chassis status

For member 1 (trefoil):

user@trefoil> show virtual-chassis status

Configuring Virtual Chassis Ports to Interconnect Member Routers

Step-by-Step Procedure

To interconnect the member routers in an MX Series Virtual Chassis, use the request virtual-chassis vc-port set command to configure (set) Virtual Chassis ports on Modular Port Concentrator/Modular Interface Card (MPC/MIC) interfaces.

Note

If you issue the request virtual-chassis vc-port set command without first installing an MX Virtual Chassis Redundancy Feature Pack license on both member routers, the software displays a warning message that you are operating without a valid Virtual Chassis software license.

To configure Virtual Chassis ports on MPC/MIC interfaces to connect the member routers in the Virtual Chassis:

  1. Configure the Virtual Chassis ports on member 0 (gladius).
    1. Log in to the console on member 0.

    2. Configure the first Virtual Chassis port that connects to member 1 (trefoil).

      user@gladius> request virtual-chassis vc-port set fpc-slot 2 pic-slot 2 port 0

      After the Virtual Chassis port is created, it is renamed vcp-slot/pic/port (for example, vcp-2/2/0), and the line card associated with that port comes online. The line cards in the other member router remain offline until the Virtual Chassis forms. Each Virtual Chassis port is dedicated to the task of interconnecting member routers in a Virtual Chassis, and is no longer available for configuration as a standard network port.

    3. When vcp-2/2/0 is up, configure the second Virtual Chassis port that connects to member 1.

      user@gladius> request virtual-chassis vc-port set fpc-slot 2 pic-slot 3 port 0
  2. Configure the Virtual Chassis ports on member 1 (trefoil).
    1. Log in to the console on member 1.

    2. Configure the first Virtual Chassis port that connects to member 0 (gladius).

      user@trefoil> request virtual-chassis vc-port set fpc-slot 2 pic-slot 0 port 0
    3. When vcp-2/0/0 is up, configure the second Virtual Chassis port that connects to member 0.

      user@trefoil> request virtual-chassis vc-port set fpc-slot 5 pic-slot 2 port 0

    When all of the line cards in all of the member routers are online and the Virtual Chassis forms, you can issue Virtual Chassis commands from the terminal window of the primary router (gladius).

  3. Verify that the Virtual Chassis is properly configured and operational.
    user@gladius> show virtual-chassis status




    user@gladius> show virtual-chassis vc-port all-members

    See the Verification section for information about interpreting the output of these commands.

  4. Commit the configuration on the primary router.

    The commit step is required to ensure that the configuration groups and Virtual Chassis configuration are propagated to both members of the Virtual Chassis.

Verification

Confirm that the configuration is working properly.





Verifying the Member IDs and Roles of the Virtual Chassis Members

Purpose

Verify that the member IDs and roles of the routers belonging to the Virtual Chassis are properly configured.

Action

Display the status of the members of the Virtual Chassis configuration.

user@gladius> show virtual-chassis status

Meaning

The value Prsnt in the Status column of the output confirms that the member routers specified in the preprovisioned configuration are currently connected to the Virtual Chassis. The display shows that member 0 (gladius) and member 1 (trefoil), which were both configured with the routing-engine role, are functioning as the primary router and backup router of the Virtual Chassis, respectively. The Neighbor List displays the interconnections between the member routers by means of the Virtual Chassis ports. For example, member 0 is connected to member 1 through vcp-2/2/0 and vcp-2/3/0. The asterisk (*) following Master denotes the router on which the command was issued. The Mastership priority value is assigned by the software and is not configurable.

Verifying the Enhanced IP Network Services Configuration

Purpose

Verify that enhanced IP network services have been properly configured for the Virtual Chassis.

Action

Display the setting of the network services configuration for the primary Routing Engine in the Virtual Chassis primary router (member0-re0), and for the primary Routing Engine in the Virtual Chassis backup router (member1-re0).

user@gladius> show chassis network services
user@trefoil> show chassis network services

Meaning

The output of the show chassis network services command confirms that enhanced IP network services are properly configured on both member routers in the Virtual Chassis.

Verifying the Operation of the Virtual Chassis Ports

Purpose

Verify that the Virtual Chassis ports are properly configured and operational.

Action

Display the status of the Virtual Chassis ports for both members of the Virtual Chassis.

user@gladius> show virtual-chassis vc-port all-members

Meaning

The output confirms that the Virtual Chassis ports you configured are operational. For each member router, the Interface or Slot/PIC/Port column shows the location of the Virtual Chassis ports configured on that router. For example, the Virtual Chassis ports on member0-re0 (gladius) are vcp-2/2/0 and vcp-2/3/0. In the Trunk ID column, the value 3 indicates that a trunk has formed; if a trunk is not present, this field displays the value -1 . In the Status column, the value Up confirms that the interfaces associated with the Virtual Chassis ports are operational. The Speed column displays the speed of the Virtual Chassis port interface. The Neighbor ID/Interface column displays the member IDs and Virtual Chassis port interfaces that connect to this router. For example, the connections to member 0 (gladius) are through vcp-2/0/0 and vcp-5/2/0 on member 1 (trefoil).

Verifying Neighbor Reachability

Purpose

Verify that each member router in the Virtual Chassis can reach the neighbor routers to which it is connected.

Action

Display the neighbor reachability information for both member routers in the Virtual Chassis.

user@gladius> show virtual-chassis active-topology all-members

Meaning

The output confirms that each member router in the Virtual Chassis has a path to reach the neighbors to which it is connected. For each member router, the Destination ID specifies the member ID of the destination (neighbor) router. The Next-hop column displays the member ID and Virtual Chassis port interface of the next hop to which packets for the destination ID are forwarded. For example, the next hop from member 0 (gladius) to member 1 (trefoil) is through Virtual Chassis port interface vcp-2/2/0.32768.