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Example: Configuring H-VPLS Without VLANs

This example shows how to configure the hierarchical virtual private LAN service (H-VPLS). No VLANs are configured in this example.

Requirements

No special configuration beyond device initialization is required before configuring this example.

Overview

H-VPLS uses LDP-based VPLS to signal and establish pseudowires. LDP-based VPLS is defined in RFC 4762, Virtual Private LAN Service (VPLS) Using Label Distribution Protocol (LDP) Signaling. RFC 4762 also defines a hierarchical mode of operation for LDP VPLS called H-VPLS.

VPLS and H-VPLS are different with respect to scaling. VPLS requires a full mesh of tunnel label-switched paths (LSPs) among all of the provider edge (PE) routers that participate in the VPLS service. For each VPLS service, n*(n-1)/2 pseudowires must be set up between the PE routers. In contrast, H-VPLS partitions the network into several edge domains that are interconnected using an MPLS core. Each edge device only needs to learn of one local PE device and therefore needs less routing table support. This has the potential to allow service providers to use relatively less costly devices (such as EX Series switches) at the customer edge.

Note:

As alternatives to H-VPLS, Juniper Networks offers other ways to address VPLS scalability. For more information, see Application Note: Demystifying H-VPLS.

H-VPLS defines two roles or functionalities:

  • PE-r—PE device that runs VPLS with other PE-r devices, but which also has pseudowires (it can be based on QinQ access) with another device called a multi-tenant unit (MTU), which provides the access layer.

  • MTU—PE device that represents the access layer on the H-VPLS architecture and establishes pseudowires to one or more PE-r devices through which VPLS traffic is forwarded.

Figure 1 shows the topology used in this example.

Figure 1: Basic H-VPLS With One MTU and Two PE-r DevicesBasic H-VPLS With One MTU and Two PE-r Devices

The example shows one MTU (Device PE1) connected to two PE-r devices (Device PE2 and Device PE3).

The pseudowire between Device PE1 and Device PE3 is the primary or working path. The pseudowire between Device PE1 and Device PE2 is the backup path.

CLI Quick Configuration shows the configuration for all of the devices in Figure 1. The section #configuration956__hvpls-simple-step-by-step describes the steps on Device PE1 and Device PE2.

Configuration

Procedure

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.

Device PE1

Device PE2

Device PE3

Device CE1

Device CE2

Device CE3

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode in the CLI User Guide.

To configure H-VPLS on the MTU device:

  1. Configure the interfaces.

    On the MTU device interface that connects to the customer edge, configure one of the circuit cross-connect (CCC) encapsulation types and the CCC address family. This enables Layer 2 circuits.

    On the core-facing interfaces, enable MPLS labels. The ISO address is needed as well on the core-facing interfaces because IS-IS is used in the core.

  2. Enable MPLS and LDP on the interfaces.

    On the MTU device interfaces that connect to other PE devices, configure MPLS and LDP.

  3. Enable routing on the interfaces.

    On the MTU device interfaces that connect to other PE devices, configure an interior gateway protocol (IGP), such as OSPF or IS-IS.

  4. Configure the Layer 2 circuit.

    The neighbor 10.255.14.225 is Device PE3’s loopback interface address. This sets up the working path.

    The neighbor 10.255.14.216 is Device PE2’s loopback interface address. This sets up the backup path.

    The virtual circuit ID must match the VPLS ID that is configured on Device PE2 and Device PE3.

  5. Configure the router ID.

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode in the CLI User Guide.

To configure H-VPLS on the MTU device:

  1. Configure the interfaces.

    On the PE-r device interface that connects to the customer edge, configure one of the VPLS encapsulation types and the VPLS address family. This enables VPLS.

    On the core-facing interfaces, enable MPLS labels. The ISO address is needed as well on the core-facing interfaces because IS-IS is used in the core.

  2. Enable MPLS and LDP on the interfaces.

    On the MTU device interfaces that connect to other PE devices, configure MPLS and LDP.

  3. Enable routing on the interfaces.

    On the MTU device interfaces that connect to other PE devices, configure an interior gateway protocol (IGP), such as OSPF or IS-IS.

  4. Configure VPLS.

    The neighbor 10.255.14.217 statement points to Device PE1’s loopback interface address.

    The VPLS ID must match the virtual circuit ID that is configured on the MTU (Device PE1).

  5. Configure the router ID.

Results

From configuration mode, confirm your configuration by entering the show interfaces, show protocols, show routing-instances, and show routing-options commands. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.

Device PE1

Device PE2

If you are done configuring the devices, enter commit from configuration mode.

Verification

Confirm that the configuration is working properly.

Verifying the Layer 2 Circuit

Purpose

Verify that the Layer 2 circuit is operational on the MTU device.

Action

From operational mode, enter the show l2circuit connections command.

Meaning

As expected, the Layer 2 circuit connection to Device PE3 is operational, and the connection to Device PE2 is in standby mode.

Checking the VPLS Connections

Purpose

Verify that the VPLS connections are operational on the PE-r devices.

Action

From operational mode, enter the show vpls connections command.

Meaning

As expected, the VPLS connections are operational on both PE-r devices.

Checking Connectivity

Purpose

Verify that Device CE1 can ping Device CE3.

Action

Meaning

The output shows that H-VPLS is operational.

Manually Triggering a Switch from the Active Pseudowire to the Redundant Pseudowire

Purpose

Make sure that the pseudowire between Device PE1 and Device PE2 becomes operational.

Action

Meaning

The successful ping from Device CE1 to Device CE2 shows that the pseudowire between Device PE1 and PE2 is operational. Now, if you ping Device CE3 from Device CE1, the ping should fail.