PPPoE on Ethernet
First Published: March 31, 2000
Last Updated: November 25, 2009
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
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 for PPPoE on Ethernet" section.
Use Cisco Feature Navigator to find information about platform support and Cisco IOS XE software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
•Prerequisites for PPPoE on Ethernet
•Restrictions for PPPoE on Ethernet
•Information About PPPoE on Ethernet
•How to Enable and Configure PPPoE on Ethernet
•Configuration Examples for PPPoE on Ethernet
•Additional References
•Feature Information for PPPoE on Ethernet
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
The following restrictions apply when the PPPoE on Ethernet feature is used:
•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
The following section has information about PPPoE on Ethernet:
•Benefits of Using 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
The following sections contain configuration tasks for the PPPoE on Ethernet feature.
•Enabling PPPoE on Ethernet in a VPDN Group (required)
•Limiting PPPoE Sessions from a MAC Address (optional)
•Creating and Configuring a Virtual Template (optional)
•Specifying an Ethernet Interface (optional)
•Enabling PPPoE on an Ethernet Interface (required)
•Monitoring and Maintaining VPDN Groups (optional)
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. vpdn enable
2. vpdn group name
3. accept dialin
4. protocol pppoe
5. virtual-template template-number
DETAILED STEPS
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Step 1 |
Router(config)# vpdn enable
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Enables virtual private dial-up networking. |
Step 2 |
Router(config-if)# vpdn group name
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Associates a VPDN group to a customer or VPDN profile. |
Step 3 |
Router(config-if)# accept dialin
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Creates an accept dial-in VPDN group. |
Step 4 |
Router(config-if)# protocol pppoe
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Specifies the VPDN group to be used to establish PPPoE sessions. |
Step 5 |
Router(config-if)# virtual-template template-number
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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:
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Router(config-if)# pppoe session-limit per-mac number
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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 Solutions 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:
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Step 1 |
Router(config)# interface virtual-template number
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Creates a virtual template, and enters interface configuration mode. |
Step 2 |
Router(config-if)# ip unnumbered ethernet number
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Enables IP without assigning a specific IP address on the LAN. |
Step 3 |
Router(config-if)# mtu bytes
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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:
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Router# interface ethernet interface-number
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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:
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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:
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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
This section provides the following configuration examples:
•PPPoE on Ethernet: Example
•Enabling PPPoE on an Ethernet Interface: Example
PPPoE on Ethernet: Example
The following are examples of the vpdn enable and interface virtual-template commands:
pppoe limit per-mac <number>
interface virtual-template 1
ip address 10.100.100.100 255.255.255.0
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:
Additional References
The following sections provide references related to the PPPoE on Ethernet feature.
Related Documents
Standards
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No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature. |
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MIBs
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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
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RFC 2516 |
A Method for Transmitting PPPoE |
RFC 4813 |
Multiprotocol Encapsulation over ATM Adaptation Layer 5 |
Technical Assistance
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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
Table 1 lists the features in this module and provides links to specific configuration information.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS XE software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note Table 1 lists only the Cisco IOS XE software release that introduced support for a given feature in a given Cisco IOS XE software release train. Unless noted otherwise, subsequent releases of that Cisco IOS XE software release train also support that feature.
Table 1 Feature Information for PPPoE on Ethernet
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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. |
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