PPPoE over VLAN Enhancements Configuration Limit Removal and ATM Support

The PPPoE over VLAN Enhancements: Configuration Limit Removal and ATM Support feature provides two enhancements to PPP over Ethernet (PPPoE) over IEEE 802.1Q VLAN functionality:

  • It removes the requirement for each PPPoE VLAN to be created on a subinterface. Removal of this requirement increases the number of VLANs that can be configured on a router to 4000 VLANs per interface.

  • It adds ATM permanent virtual circuit (PVC) support for PPPoE over VLAN traffic that uses bridged RFC 1483 encapsulation.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and 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.

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.

Restrictions for PPPoE over VLAN Enhancements Configuration Limit Removal and ATM Support

PPPoE over IEEE 802.1Q VLAN support can be configured without using subinterfaces on the PPPoE server only.

ATM PVC support for PPPoE over IEEE 802.1Q VLANs can be configured only on the PPPoE server.

It is not possible to shut down traffic for individual VLANs that are configured on the main interface. Individual VLANs that are configured on subinterfaces can be shut down.

A VLAN range can be configured on a main interface at the same time that VLANs outside the range are configured on subinterfaces of the same main interface. However, you cannot configure a specific VLAN on the main interface and on a subinterface at the same time.

Information About PPPoE over VLAN Configuration Limit Removal and ATM Support

To configure PPPoE over IEEE 802.1Q VLAN support on an interface rather than a subinterface, and to configure ATM support for PPPoE over IEEE 802.1Q VLANs, you should understand the following concepts:

PPPoE over VLAN Configuration Without Using Subinterfaces

The PPPoE over VLAN Enhancements: Configuration Limit Removal and ATM Support feature removes the requirement for each PPPoE VLAN to be created on a subinterface. Allowing more than one PPPoE VLAN to be configured on a main interface increases the number of VLANs that can be configured on a router to 4000 VLANs per interface.

Individual VLANs or a range of VLANs can be configured on an interface. You can configure a VLAN range on a main interface and at the same time configure VLANs outside the range on subinterfaces of the same interface.

PPPoE over VLAN Support on ATM PVCs

The PPPoE over VLAN Enhancements: Configuration Limit Removal and ATM Support feature enables ATM PVCs to process PPPoE over VLAN packets that use bridged RFC 1483 encapsulation. This capability allows PPPoE traffic from different IEEE 802.1Q VLANs to be multiplexed over the same ATM PVC.

The figure below shows a sample network topology that implements PPPoE over VLAN on ATM PVCs. In this topology, a service provider is using an Ethernet switch to provide Ethernet service to home users and a single PVC to provide the switch with WAN access. The home users use PPPoE to access services on the network access server (NAS). Each port on the switch is assigned a separate VLAN, and the VLANs are trunked over a Fast Ethernet or Gigabit Ethernet interface that is connected to a digital subscriber line (DSL) modem acting as a bridge.

The IEEE 802.1Q VLAN-encapsulated traffic coming in from the Ethernet switch trunk is encapsulated in RFC 1483 bridged encapsulation by the DSL modem and sent across the ATM WAN to the NAS. The NAS, which is configured to support PPPoE over VLANs over ATM PVCs, will extract the PPPoE packet from the PPPoE over IEEE 802.1Q VLAN over RFC 1483 bridged encapsulation and provide PPPoE services to the user.

In the downlink, the NAS sends packets in PPPoE over IEEE 802.1Q VLAN over RFC 1483 bridged encapsulation. The DSL modem strips off the RFC 1483 encapsulation and forwards the IEEE 802.1Q VLAN packets across the trunk to the switch. The switch then sends the Ethernet packets to the port associated with the IEEE 802.1 VLAN ID.

Figure 1. Sample Network Topology for PPPoE over IEEE 802.1Q VLANs over ATM

Benefits of PPPoE over VLAN Enhancements Configuration Limit Removal and ATM Support

The PPPoE over VLAN Enhancements: Configuration Limit Removal and ATM Support feature has the following benefits:

  • Increases the number of VLANs that can be configured on a router to 4000 VLANs per interface by removing the requirement for each PPPoE VLAN to be configured on a subinterface.

  • Provides support for PPPoE over VLANs over ATM interfaces using RFC 1483 bridged encapsulation

How to Configure PPPoE over VLAN Enhancements Configuration Limit Removal and ATM Support

Configuring PPPoE over IEEE 802.1Q VLAN Support on an Ethernet Interface

Perform this task to configure PPPoE over IEEE 802.1Q VLAN support on an Ethernet interface.

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    interface type number

    4.    Do one of the following:

    • vlan-id dot1q vlan-id
    • vlan-range dot1q start-vlan-id end-vlan-id

    5.    pppoe enable [group group-name]


DETAILED STEPS
     Command or ActionPurpose
    Step 1 enable


    Example:
    Router> enable
     

    Enables privileged EXEC mode.

    • Enter your password if prompted.

     
    Step 2 configure terminal


    Example:
    Router# configure terminal
     

    Enters global configuration mode.

     
    Step 3 interface type number


    Example:
    Router(config)# interface fastethernet 0/2
     

    Specifies the interface to be configured and enters interface configuration mode.

     
    Step 4Do one of the following:
    • vlan-id dot1q vlan-id
    • vlan-range dot1q start-vlan-id end-vlan-id


    Example:
    Router(config-if)# vlan-id dot1q 0


    Example:


    Example:
    Router(config-if)# vlan-range dot1q 0 60
     

    Enables IEEE 802.1Q VLAN encapsulation for a specific VLAN on an Ethernet interface.

    or

    Enables IEEE 802.1Q VLAN encapsulation for a range of VLANs on an Ethernet interface.

     
    Step 5 pppoe enable [group group-name]


    Example:
    Router(config-if-vlan-range)# pppoe enable group pppoe1
     

    Enables PPPoE sessions over a specific VLAN or a range of VLANs.

     

    Configuring an ATM PVC to Support PPPoE over IEEE 802.1Q VLAN Traffic

    Perform this task to configure an ATM PVC to support RFC 1483 bridge encapsulated PPPoE over IEEE 802.1Q VLAN traffic.

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    interface atm number . subinterface-number {multipoint | point-to-point}

      4.    pvc [name] vpi / vci

      5.    protocol pppovlan dot1q {vlan-id | start-vlan-id end-vlan-id} [group group-name]


    DETAILED STEPS
       Command or ActionPurpose
      Step 1 enable


      Example:
      Router> enable
       

      Enables privileged EXEC mode.

      • Enter your password if prompted.

       
      Step 2 configure terminal


      Example:
      Router# configure terminal
       

      Enters global configuration mode.

       
      Step 3 interface atm number . subinterface-number {multipoint | point-to-point}


      Example:
      Router(config)# interface atm 2/0.1 multipoint
       

      Configures an ATM multipoint subinterface and enters subinterface configuration mode.

       
      Step 4 pvc [name] vpi / vci


      Example:
      Router(config-subif)# pvc 0/60
       

      Configures a PVC and enters ATM VC configuration mode.

       
      Step 5 protocol pppovlan dot1q {vlan-id | start-vlan-id end-vlan-id} [group group-name]


      Example:
      Router(config-if-atm-vc)# protocol pppovlan dot1q 0 50 group pppoe1
       

      Enables PPPoE for a specific IEEE 802.1Q VLAN or a range of VLANs on an ATM PVC.

       

      Configuring a VC Class for PPPoE over IEEE 802.1Q VLAN Support

      Perform this task to configure support for PPPoE over IEEE 802.1Q VLANs in a VC class.

      SUMMARY STEPS

        1.    enable

        2.    configure terminal

        3.    vc-class atm name

        4.    protocol pppovlan dot1q {vlan-id | start-vlan-id end-vlan-id} [group group-name]


      DETAILED STEPS
         Command or ActionPurpose
        Step 1 enable


        Example:
        Router> enable
         

        Enables privileged EXEC mode.

        • Enter your password if prompted.

         
        Step 2 configure terminal


        Example:
        Router# configure terminal
         

        Enters global configuration mode.

         
        Step 3 vc-class atm name


        Example:
        Router(config)# vc-class atm class1
         

        Configures an ATM VC class and enters VC-class configuration mode.

         
        Step 4 protocol pppovlan dot1q {vlan-id | start-vlan-id end-vlan-id} [group group-name]


        Example:
        Router(config-vc-class)# protocol pppovlan dot1q 0 50 group pppoe1
         

        Enables support for PPPoE for a specific IEEE 802.1Q VLAN or a range of VLANs in a VC class.

        Note   

        A VC class can be applied to an ATM interface, subinterface, PVC, or range of PVCs.

         

        Monitoring and Maintaining PPPoE over IEEE 802.1Q VLAN

        Perform this task to monitor and maintain PPPoE over VLAN connections.

        SUMMARY STEPS

          1.    enable

          2.    clear pppoe {interface type number [vc {[vpi/]vci | vc-name}] [vlan vlan-id] | rmac mac-address [sid session-id] | all}

          3.    debug pppoe {data | errors | events | packets} [rmac remote-mac-address | interface type number[vc {[vpi /]vci | vc-name}] [vlan vlan-id]]


        DETAILED STEPS
           Command or ActionPurpose
          Step 1 enable


          Example:
          Router> enable
           

          Enables privileged EXEC mode.

          • Enter your password if prompted.

           
          Step 2 clear pppoe {interface type number [vc {[vpi/]vci | vc-name}] [vlan vlan-id] | rmac mac-address [sid session-id] | all}


          Example:
          Router# clear pppoe interface fastethernet 0/2 vlan 1
           

          Clears PPPoE sessions.

           
          Step 3 debug pppoe {data | errors | events | packets} [rmac remote-mac-address | interface type number[vc {[vpi /]vci | vc-name}] [vlan vlan-id]]


          Example:
          Router# debug pppoe events interface atm 0/0 vc 1/16 vlan 10
           

          Displays debugging information for PPPoE sessions.

           

          Configuration Examples for PPPoE over VLAN Enhancements Configuration Limit Removal and ATM Support

          Configuring PPPoE over IEEE 802.1Q VLAN Support on an Ethernet Interface Example

          The following example shows how to configure PPPoE over a range of IEEE 802.1Q VLANs on Fast Ethernet interface 0/0. The VLAN range is configured on the main interface and therefore each VLAN will not use up a separate subinterface.

          bba-group pppoe PPPOE 
 virtual-template 1 
 sessions per-mac limit 1 
interface virtual-template 1 
 ip address 10.10.10.10 255.255.255.0 
 mtu 1492 
interface fastethernet 0/0
 no ip address 
 no ip mroute-cache 
 duplex half 
 vlan-range dot1q 20 30 
  pppoe enable group PPPOE 
  exit-vlan-config

          Configuring PPPoE over IEEE 802.1Q VLAN Support on ATM PVCs Example

          The following example shows how to configure an ATM PVC to support PPPoE over a range of IEEE 802.1Q VLANs:

          bba-group pppoe PPPOEOA
 virtual-template 1 
 sessions per-mac limit 1 
interface virtual-template 1 
 ip address 10.10.10.10 255.255.255.0 
 mtu 1492 
interface atm 4/0.10 multipoint 
 pvc 10/100 
  protocol pppovlan dot1q range 10 30 group PPPOEOA

          Additional References

          The following sections provide references related to the PPPoE Over VLAN Enhancements: Configuration Limit Removal and ATM Support feature.

          Related Documents

          Related Topic

          Document Title

          ATM PVC configuration

          ATM chapter of the Cisco IOS Wide-Area Networking Configuration Guide

          PPPoE and PPPoE over IEEE 802.1Q VLAN configuration

          Broadband Access: PPP and Routed Bridge Encapsulation chapter of the Cisco IOS Wide-Area Networking Configuration Guide

          VLAN range configuration (using subinterfaces)

          VLAN Range feature module

          ATM PVC and PPPoE configuration commands

          Cisco IOS Wide-Area Networking Command Reference

          Standards

          Standard

          Title

          IEEE Standard 802.1Q, 1998

          Virtual Bridged Local Area Networks

          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 releases, and feature sets, use Cisco MIB Locator found at the following URL:

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

          RFCs

          RFC

          Title

          RFC 1483

          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 over VLAN Enhancements Configuration Limit Removal and ATM Support

          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 1 Feature Information for PPPoE over VLAN Enhancements: Configuration Limit Removal and ATM Support

          Feature Name

          Releases

          Feature Information

          PPPoE over VLAN Enhancements: Configuration Limit Removal and ATM Support

          12.2 (31)SRC

          12.3(2)T

          12.2(33)SB

          Cisco IOS Release XE 3.9S

          The PPPoE over VLAN Enhancements: Configuration Limit Removal and ATM Support feature provides two enhancements to PPP over Ethernet (PPPoE) over IEEE 802.1Q VLAN functionality:

          • It removes the requirement for each PPPoE VLAN to be created on a subinterface. Removal of this requirement increases the number of VLANs that can be configured on a router to 4000 VLANs per interface.

          • It adds ATM permanent virtual circuit (PVC) support for PPPoE over VLAN traffic that uses bridged RFC 1483 encapsulation.

          In Cisco IOS Release 12.2(31)SRC, this feature was introduced.

          In Cisco IOS Release 12.3(2)T, this feature was integrated into the T train.

          In Cisco IOS Release 12.2(33)SB, support was added for the Cisco IOS 10000 series routers.

          The following commands were introduced or modified:

          clear pppoe , debug pppoe, pppoe enable, protocol pppovlan dot1q, vlan-id dot1q, vlan-range dot1q.