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Example: Configuring a Dynamic PPPoE Subscriber Interface on a Static Underlying VLAN Demux Interface over Aggregated Ethernet

 

This example shows how you can configure dynamic PPPoE subscriber interfaces over aggregated Ethernet bundles to provide subscriber link redundancy.

Requirements

PPPoE over VLAN demux interfaces over aggregated Ethernet requires the following hardware and software:

  • MX Series 5G Universal Routing Platforms

  • MPCs

  • Junos OS Release 11.2 or later

No special configuration beyond device initialization is required before you can configure this feature.

Overview

Aggregated Ethernet bundles enable link redundancy between the router and networking devices connected by Ethernet links. This example describes how to configure link redundancy for dynamic PPPoE subscribers over aggregated Ethernet interface, ae0, with an intermediate static VLAN demux interface, demux0.100. Sample tasks include configuring a two-member aggregated Ethernet bundle, configuring a static VLAN demux interface that underlies the PPPoE subscriber interface, and configuring the dynamic profile that establishes the dynamic PPPoE subscriber interfaces.

The dynamic PPPoE profile (pppoe-profile) creates the PPPoE subscriber interface. It also configures the router to act as a PPPoE server and enables the local address to be derived from the specified address without assigning an explicit IP address to the interface. The pppoe-profile dynamic profile is assigned to the static, intermediate VLAN demux interface (demux0.100), which is configured with the PPPoE family (family pppoe) attributes. This dynamic profile includes the following predefined variables:

  • $junos-interface-unit—Represents the logical unit number of the dynamic PPPoE logical interface. This predefined variable is dynamically replaced with the unit number supplied by the router when the subscriber logs in.

  • $junos-underlying-interface—Represents the name of the underlying Ethernet interface. This predefined variable is dynamically replaced with the interface name supplied by the router when the subscriber logs in.

This example does not show all possible configuration choices.

Configuration

CLI Quick Configuration

To quickly configure link redundancy for dynamic PPPoE subscribers over a static VLAN demux interface over aggregated Ethernet, copy the following commands, paste them in a text file, remove any line breaks, and then copy and paste the commands into the CLI.

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For instructions on how to do that, see Using the CLI Editor in Configuration Mode.

To configure link redundancy for dynamic PPPoE subscribers over a static VLAN demux interface over aggregated Ethernet:

  1. Define the number of aggregated Ethernet devices on the router.
  2. Configure a two-link aggregated Ethernet logical interface to serve as the underlying interface for the static VLAN demux subscriber interface. In this example, the LAG bundle is configured for one-to-one active/backup link redundancy. To support link redundancy at the MPC level, the LAG bundle attaches to ports from two different MPCs.
  3. Enable link protection on the aggregated Ethernet logical interface and configure support for single and dual (stacked) VLAN tags.
  4. Configure the VLAN demux interface over the aggregated Ethernet logical interface.
  5. Configure the PPPoE family attributes on the VLAN demux interface, including the dynamic profile.
  6. Configure the dynamic profile that creates the PPPoE subscriber interfaces.

Results

From configuration mode, confirm the aggregated device configuration by entering the show chassis command. Confirm the interface configuration by entering the show interfaces command. Confirm the dynamic profile configuration by entering the show dynamic-profiles command. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

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

Verification

To confirm that the configuration is working properly, perform these tasks:

Verifying the Aggregated Ethernet Interface Configuration

Purpose

Verify that the interface values match your configuration, the link is up, and traffic is flowing.

Action

From operational mode, enter the show interfaces redundancy command.

user@host> show interfaces redundancy

From operational mode, enter the show interfaces ae0 command.

user@host> show interfaces ae0

Meaning

The show interfaces redundancy output shows the redundant link configuration and that both link interfaces are up. The show interfaces ae0 output shows that the aggregated Ethernet interface is up and that traffic is being received on the logical interface.

Verifying the demux0 Interface Configuration

Purpose

Verify that the VLAN demux interface displays the configured PPPoE family attributes and the member links in the aggregated Ethernet bundle.

Action

From operational mode, enter the show interfaces demux0 command.

user@host> show interfaces demux0.100

Alternatively, you can enter show pppoe underlying-interfaces detail to display the state and PPPoE family configuration for all configured underlying interfaces. The output also provides information about PPPoE negotiation on a per-VLAN basis.

Meaning

The output shows the name of the underlying interface, the member links of the aggregated bundle, and the PPPoE family configuration. The output shows packet counts when traffic is present on the logical interface.