Configuring PPP over Ethernet Session Limit Support

This module provides information on how to limit the number of PPP over Ethernet (PPPoE) sessions that can be created on a router or on a Gigabit Ethernet interface for configuration.

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.

Information About Configuring PPP over Ethernet Session Limit Support

Benefits of Configuring PPP over Ethernet Session Limit Support

  • The PPPoE Session Limit Support feature prevents the router from using too much memory for virtual access by limiting the number of PPPoE sessions that can be created on a router or on all Ethernet interfaces and subinterfaces as well as ATM interfaces and subinterfaces.

  • The SNMP Enhancements for ASR 1000 feature enhances Cisco ASR 1000 Aggregation Series Router to count the PPPoE sessions in PTA, FWDED, and TRANS state for a particular physical interface, and the total number of sessions that exist in a physical interface. Provision for using a system-wide threshold trap and per-physical threshold trap is provided through SNMP. These functionalities enable users to retrieve the total number of sessions and per-interface session-loss threshold value.

Trap Generation

In scenarios where you must deploy ASR 1000 Series Routers with one physical port mapped to one DSLAM and if the total number of sessions for the DSLAM falls below the threshold value on a physical interface, due to a loss of high number of sessions, a notification trap is generated. You can use these traps to investigate the issue and take immediate actions.

When the number of active sessions falls below the threshold value, only one trap is generated. Further traps are not sent even if the number of sessions continue to decrease. The next set of traps are sent only if the number of sessions rise above the configured threshold value and fall. This criterion is applicable to both global and per-interface traps.

When threshold values are configured in both global and per-interface configuration modes, then both the threshold values are monitored separately. Traps are sent when the session count falls below the threshold value either in global configuration mode or in per-interface configuration mode.

How to Configure PPP over Ethernet Session Limit Support

Specifying the Maximum Number of PPPoE Sessions on a Router

Perform this task to specify the maximum number of PPPoE sessions that can be created on a router.

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    bba-group pppoe {name | global}

    4.    virtual-template template-number

    5.    sessions per-mac limit per-mac-limit

    6.    sessions per-vlan limit per-vlan-limit [inner vlan-id]

    7.    sessions per-vc limit per-vc-limit [threshold threshold-value]

    8.    sessions max limit number-of-sessions [threshold threshold-value]

    9.    exit


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 bba-group pppoe {name | global}


    Example:
    Router(config)# bba-group pppoe global
     

    Configures a broadband aggregation (BBA) group to be used to establish PPPoE sessions and enters BBA group configuration mode.

    • name --Name of the BBA group. You can have multiple BBA groups.

    • global -- Specifies the PPPoE profile that serves as the default profile for any PPPoE port (Gigabit Ethernet interface or VLAN) that has not been assigned a specific PPPoE profile.

     
    Step 4 virtual-template template-number


    Example:
    Router(config-bba-group)# virtual-template 1
     

    Specifies the virtual template that will be used to clone virtual access interfaces for all PPPoE ports that use this PPPoE profile.

     
    Step 5 sessions per-mac limit per-mac-limit


    Example:
    Router(config-bba-group)# sessions per-mac limit 1000
     

    (Optional) Configures the maximum number of PPPoE sessions allowed per MAC session limit in a PPPoE profile. The default MAC session limit is 100.

     
    Step 6 sessions per-vlan limit per-vlan-limit [inner vlan-id]


    Example:
    Router(config-bba-group)# session per-vlan limit 4000 inner 3500
     

    (Optional) Sets the session limit for the inner VLAN on QinQ subinterface. The default session limit is 100.

    Note   

    The per-VLAN limit is only applicable to Gigabit Ethernet subinterfaces (802.1q VLANs).

     
    Step 7 sessions per-vc limit per-vc-limit [threshold threshold-value]


    Example:
    Router(config-bba-group)# sessions per-vc limit 2000
     

    (Optional) Sets the maximum number of PPPoE sessions allowed per VC session limit in a PPPoE profile. The default session limit is 100.

    Note   

    The per-VC limit is applicable only to ATM interfaces and subinterfaces.

     
    Step 8 sessions max limit number-of-sessions [threshold threshold-value]


    Example:
    Router(config-bba-group)# sessions max limit 32000
     

    Configures the PPPoE global profile with the maximum number of PPPoE sessions that will be permitted on a router, and sets the PPPoE session-count threshold at which a Simple Network Management Protocol (SNMP) trap will be generated.

    Note   

    This command applies only to the global profile.

     
    Step 9 exit


    Example:
    Router(config-bba-group)# exit
     

    Returns to global configuration mode.

     

    Specifying the Maximum Number of PPPoE Sessions on a Gigabit Ethernet Interface

    Perform this task to specify the maximum number of PPPoE sessions that can be created on a Gigabit Ethernet interface.

    SUMMARY STEPS

      1.    enable

      2.    configure terminal

      3.    interface {GigabitEthernet | tenGigabitEthernet} slot / subslot / port[. subinterface]

      4.    pppoe enable [group group-name]

      5.    pppoe max-sessions number

      6.    end


    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 {GigabitEthernet | tenGigabitEthernet} slot / subslot / port[. subinterface]


      Example:
      Router(config)# interface GigabitEthernet0/0/1
       

      Specifies a Gigabit Ethernet interface and enters interface configuration mode.

       
      Step 4 pppoe enable [group group-name]


      Example:
      Router(config-if)# pppoe enable group one
       

      Enables PPPoE sessions on a Gigabit Ethernet interface or subinterface.

      Note   

      If a PPPoE profile is not assigned to the interface through the use of the group group-name option, the interface will use the global PPPoE profile.

       
      Step 5 pppoe max-sessions number


      Example:
      Router(config-if)# pppoe max-sessions 10
       

      Specifies the maximum number of PPPoE sessions permitted on the interface or subinterface.

       
      Step 6 end


      Example:
      Router(config-if)# end
       

      (Optional) Exits interface configuration mode and returns to privileged EXEC mode.

       

      Configuring System-Wide Threshold Parameters

      Performthis task to configure the system-wide threshold parameters.

      SUMMARY STEPS

        1.    enable

        2.    configure terminal

        3.    bba-group ppp oe globa l

        4.    sessions threshold number

        5.    exit

        6.    interface type number

        7.    pppoe-sessions threshold number

        8.    end

        9.    show pppoe summary


      DETAILED STEPS
         Command or ActionPurpose
        Step 1 enable


        Example:
        Router> enable
         

        Enables privileged EXEC mode.

         
        Step 2 configure terminal


        Example:
        Router> configure terminal
         

        Enters global configuration mode.

         
        Step 3 bba-group ppp oe globa l


        Example:
        Router(config)# bba-group pppoe global
         

        Defines a PPPoE profile and enters BBA group configuration mode.

         
        Step 4 sessions threshold number


        Example:
        Router(config-bba-group)# sessions threshold 1000
         

        Configures the global threshold value.

         
        Step 5 exit


        Example:
        Router(config-bba-group)# exit
         

        Exits BBA group configuration mode and returns to privileged EXEC mode.

         
        Step 6 interface type number


        Example:
        Router(config-if)# interface GigabitEthernet 0/0
         

        Enters interface configuration mode.

         
        Step 7 pppoe-sessions threshold number


        Example:
        Router(config-if)# pppoe-sessions threshold 1000
         

        Configures per-session threshold value.

         
        Step 8 end


        Example:
        Router(config-if)# end
         

        Exits interface configuration mode and returns to privileged EXEC mode

         
        Step 9 show pppoe summary


        Example:
        Router# show pppoe summary
         

        Displays the count of PPPoE sessions in PTA, FWDED, and TRANS state for a particular physical interface.

         

        Configuration Examples for PPP over Ethernet Session Limit Support

        Example Specifying the Maximum Number of PPPoE Sessions on a Router

        The following example shows how to configure a limit of 1,000 PPPoE sessions for the router:

        bba-group pppoe global
  virtual-template 1
  sessions per-mac limit 1000
  sessions per-vlan limit 4000 inner 3500
  sessions per-vc limit 2000

        Example Specifying the Maximum Number of PPPoE Sessions on a Gigabit Ethernet Interface

        The following example shows how to configure a limit of ten PPPoE sessions on the Gigabit Ethernet interface: 

        interface GigabitEthernet 1/0/0
  pppoe enable
  pppoe max-sessions 10

        The following example shows how to configure a limit of ten PPPoE sessions on the Gigabit Ethernet subinterface by using the encapsulationcommand: 

        interface GigabitEthernet 0/0/0.1
  encapsulation dot1q 2 
  pppoe enable
  pppoe max-sessions 10

        Example Configuring the System-wide Threshold Parameters

        The following example shows how to configure global and per-session threshold values: 

        Router# configure terminal
Router(config)# bba-group pppoe global
 Router(config-bba-group)# sessions threshold 1000
Router(config-bba-group)# exit
Router# configure terminal

        Router(config)# interface GigabitEthernet 0/0
        Router(config-if)# pppoe-sessions threshold 90
Router(config-if)# end

        The following example shows how to use the show pppoe summary command to display the count of the PPPoE sessions: 

        Router# show pppoe summary
PTA  : Locally terminated sessions
FWDED: Forwarded sessions
TRANS: All other sessions (in transient state)
TOTAL PTA   FWDED TRANS
TOTAL 1       1       0       0
GigabitEthernet0/3/1 1       1       0       0

        Additional References

        Related Documents

        Related Topic

        Document Title

        Cisco IOS commands

        Cisco IOS Master Commands List, All Releases

        Broadband and DSL commands

        Cisco IOS Broadband and DSL Command Reference

        Broadband access aggregation of PPPoE sessions

        Providing Protocol Support for Broadband Access Aggregation of PPPoE Sessions

        Standards

        Standards

        Title

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

        --

        MIBs

        MIBs

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

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

        RFCs

        RFCs

        Title

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

        --

        Technical Assistance

        Description

        Link

        The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.

        http:/​/​www.cisco.com/​cisco/​web/​support/​index.html

        Feature Information for Configuring PPP over Ethernet Session Limit 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 Providing PPP over Ethernet Session Limit Support

        Feature Name

        Releases

        Feature Information

        PPP over Ethernet Session Limit Support

        Cisco IOS XE Release 2.1 Cisco IOS XE Release 2.4

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

        The PPPoE Session Limit Support feature enables you to limit the number of PPPoE sessions that can be created on a router or on a Gigabit Ethernet interface for configuration.

        This feature was integrated into Cisco IOS XE Release 2.4.

        SNMP Enhancements for ASR 1000

        Cisco IOS XE Release 3.2S

        The SNMP Enhancements for ASR 1000 feature enhances Cisco ASR 1000 Aggregation Series Routers to provide the count of the PPPOE sessions in PTA, Forwarded, and TRANS state for a particular physical interface, and the total count of sessions that exist in a physical interface.

        This feature was introduced in Cisco IOS XE 3.2S.

        The following commands were introduced or modified: pppoe-sessions threshold, sessions threshold.