Broadband Access Aggregation and DSL Configuration Guide, Cisco IOS XE Release 2
PPPoE on Ethernet
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Contents

PPPoE on Ethernet

Last Updated: December 4, 2011

The PPPoE on Ethernet feature adds support to Point-to-Point Protocol over Ethernet (PPPoE) by adding direct connection to actual Ethernet interfaces. PPPoE provides service-provider digital subscriber line (DSL) support. This Ethernet specification can be used by multiple hosts on a shared Ethernet interface to open PPP sessions to multiple destination with one or more bridging modems.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the Feature Information Table at the end of this document.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Prerequisites for PPPoE on Ethernet

Before you can configure the PPPoE on Ethernet feature, you need to configure a virtual private dialup network (VPDN) group using the accept dialin command, enable PPPoE, and specify a virtual template for PPPoE sessions.

Restrictions for PPPoE on Ethernet

  • PPPoE is not supported on Frame Relay.
  • PPPoE is not supported on any other LAN interfaces such as FDDI and Token Ring.
  • Fast switching is supported. PPP over Ethernet over RFC 1483 fibswitching is supported for IP. All other protocols are switched over process switching.

Information About PPPoE on Ethernet

Benefits of Using PPPoE on Ethernet

Broadband Remote Access

For a bridged-Ethernet topology, the PPPoE on Ethernet feature allows access providers to maintain session abstraction associated with PPP networks.

PPPoE

PPPoE provides the ability to connect a network of hosts over a simple bridging access device to a remote access concentrator where each host utilizes its own PPP stack. It also gives users a familiar interface.

PPPoE provides service-provider DSL support. In service-provider DSL deployments, PPPoE leverages Ethernet scale curves and it uses an embedded base.

How to Enable and Configure PPPoE on Ethernet

Enabling PPPoE on Ethernet in a VPDN Group

To configure the physical interface that will carry the PPPoE session and link it to the appropriate virtual template interface, you need to complete the following steps.

SUMMARY STEPS

1.    Router(config)# vpdn enable

2.    Router(config-if)# vpdn group name

3.    Router(config-if)# accept dialin

4.    Router(config-if)# protocol pppoe

5.    Router(config-if)# virtual-template template-number


DETAILED STEPS
 Command or ActionPurpose
Step 1
Router(config)# vpdn enable 

Enables virtual private dial-up networking.

 
Step 2
Router(config-if)# vpdn group name 

Associates a VPDN group to a customer or VPDN profile.

 
Step 3
Router(config-if)# accept dialin 

Creates an accept dial-in VPDN group.

 
Step 4
Router(config-if)# protocol pppoe 

Specifies the VPDN group to be used to establish PPPoE sessions.

 
Step 5
Router(config-if)# virtual-template template-number 

Specifies which virtual template will be used to clone virtual access interfaces.

 

Limiting PPPoE Sessions from a MAC Address

To set the limit of sessions to be sourced from a MAC address, use the following command in VPDN configuration mode:

Command

Purpose

 
Router(config-if)# pppoe session-limit per-mac
 
number

Sets the limit of sessions to be sourced from a MAC address.

Creating and Configuring a Virtual Template

Other optional configuration commands can be added to the virtual template configuration. For example, you can enable the PPP authentication on the virtual template using the ppp authentication chap command. See the " Virtual Interface Template Service " chapter in the Cisco IOS Dial S>olutions Configuration Guide for more information about configuring the virtual template.

Although Cisco Express Forwarding switching is supported, flow, and optimum switching are not; these configurations are ignored on the PPPoE virtual access interface. Cisco Express Forwarding is enabled by default for IP. All other protocol traffic will be processed switched.


Note
The PPP reliable link that uses Link Access Procedure, Balanced (LAPB) is not supported.

To create and configure a virtual template, use the following commands beginning in global configuration mode:

SUMMARY STEPS

1.    Router(config)# interface virtual-template number

2.    Router(config-if)# ip unnumbered ethernet number

3.    Router(config-if)# mtu bytes


DETAILED STEPS
 Command or ActionPurpose
Step 1
Router(config)# interface virtual-template number  

Creates a virtual template, and enters interface configuration mode.

 
Step 2
Router(config-if)# ip unnumbered ethernet number  

Enables IP without assigning a specific IP address on the LAN.

 
Step 3
Router(config-if)# mtu bytes  

Sets the maximum transmission unit (MTU) size for the interface.

 

Specifying an Ethernet Interface

After you create a virtual template for PPPoE on Ethernet, specify a multipoint or point-to-point interface. To specify an Ethernet multipoint interface, use the following commands in global configuration mode:

Command

Purpose

 
Router# interface ethernet
 
interface-number

Specifies the Ethernet interface using the appropriate format of the interface ethernet command.

Enabling PPPoE on an Ethernet Interface

To enable PPPoE on Ethernet interfaces, use the following command in global configuration mode:

Command

Purpose

 
Router# pppoe enable

Specifies the VPDN group to be used for establishing PPPoE sessions.

Monitoring and Maintaining VPDN Groups

To monitor and maintain VPDN groups, use the following commands in EXEC mode:

Command

Purpose

 
Router# show vpdn

Displays information about active Level 2 Forwarding (L2F) Protocol tunnel and message identifiers in a VPDN.

 
Router# show vpdn session packet

Displays PPPoE session statistics.

 
Router# show vpdn session all

Displays PPPoE session information for each session ID.

 
Router# show vpdn tunnel

Displays PPPoE session count for the tunnel.

Configuration Examples for PPPoE on Ethernet

PPPoE on Ethernet Example

The following are examples of the vpdn enable and interface virtual-template commands:

vpdn enable
 
 vpdn-group 1
 accept dialin
 protocol pppoe
 virtual template 1
 pppoe limit per-mac <number>
 
 interface virtual-template 1
 ip address 10.100.100.100 255.255.255.0
 mtu 1492

For PPPoE virtual template interfaces, the mtu command must be configured because Ethernet has a maximum payload size of 1500 bytes, the PPPoE header is 6 bytes, and PPP Protocol ID is 2 bytes.


Note
Dial-out mode will not be supported.

Enabling PPPoE on an Ethernet Interface Example

The following example enables PPPoE on an Ethernet interface:

interface ethernet1/0 
 pppoe enable

Additional References

The following sections provide references related to the PPPoE on Ethernet feature.

Related Documents

Related Topic

Document Title

Configuring PPPoE on ATM

PPPoE over ATM

Configuring PPPoE on cable interfaces

Configuring PPPoE on IEEE 802.1Q encapsulation

PPPoE Over IEEE 802.1Q VLANs

Standards

Standard

Title

No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.

--

MIBs

MIB

MIBs Link

No new or modified MIBs are supported by this feature, and support for existing MIBs has not been modified by this feature.

To locate and download MIBs for selected platforms, Cisco IOS XE releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs

RFCs

RFC

Title

RFC 2516

A Method for Transmitting PPPoE

RFC 4813

Multiprotocol Encapsulation over ATM Adaptation Layer 5

Technical Assistance

Description

Link

The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies.

To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds.

Access to most tools on the Cisco Support website requires a Cisco.com user ID and password.

http://www.cisco.com/techsupport

Feature Information for PPPoE on Ethernet

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Table 1Feature Information for PPPoE on Ethernet

Feature Name

Releases

Feature Information

PPPoE on Ethernet

Cisco IOS XE Release 2.5

This feature was introduced on Cisco ASR 1000 Series Aggregation Services Routers.

The PPPoE on Ethernet feature adds support to Point-to-Point Protocol over Ethernet (PPPoE) by adding direct connection to actual Ethernet interfaces. PPPoE provides service-provider digital subscriber line (DSL) support. This Ethernet specification can be used by multiple hosts on a shared Ethernet interface to open PPP sessions to multiple destination with one or more bridging modems.

Cisco and the Cisco logo are trademarks or registered trademarks of Cisco and/or its affiliates in the U.S. and other countries. To view a list of Cisco trademarks, go to this URL: www.cisco.com/go/trademarks. Third-party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1110R)

Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.

© 2011 Cisco Systems, Inc. All rights reserved.