Table Of Contents
Supported Standards, MIBs, and RFCs
Limiting the Number of PPPoE Sessions on the Router
Limiting the Number of PPPoE Sessions on a PVC
Limiting the Number of PPPoE Sessions in a VC Class
Limiting the Number of PPPoE Sessions in an ATM PVC Range
Limiting the Number of PPPoE Sessions on an Individual PVC Within a PVC Range
Verifying PPPoE Session Limits
Monitoring and Maintaining PPPoE Session Limits
Limiting the Number of PPPoE Sessions on the Router Example
Limiting the Number of PPPoE Sessions on a PVC Example
Limiting the Number of PPPoE Sessions in a VC Class Example
Limiting the Number of PPPoE Sessions in an ATM PVC Range Example
Limiting the Number of PPPoE Sessions on an Individual PVC Within a PVC Range Example
PPPoE Session Limit
Feature History
Release Modification12.2(1)DX
This feature was introduced.
12.2(2)DD
This feature was integrated into Cisco IOS Release 12.2(2)DD.
This document describes the PPPoE Session Limit feature in Cisco IOS Release 12.2(2)DD. It includes the following sections:
•Supported Standards, MIBs, and RFCs
•Monitoring and Maintaining PPPoE Session Limits
Feature Overview
The PPP over Ethernet (PPPoE) Session Limit feature enables you to limit the number of PPPoE sessions that can be created on a router or on an ATM permanent virtual connection (PVC), PVC range, virtual circuit (VC) class, or Ethernet subinterface.
Before the introduction of this feature, there was no way to limit the number of PPPoE sessions that could be created on a router. Not having a limit was potentially a problem because it was possible that the router could create so many PPPoE sessions that it would run out of memory.
To prevent the router from using too much memory for virtual access, the PPPoE Session Limit feature introduces a new command and a modification to an existing command that enable you to specify the maximum number of PPPoE sessions that can be created. The new pppoe limit max-sessions command limits the number of PPPoE sessions that can be created on the router. The modified pppoe max-sessions command limits the number of PPPoE sessions that can be created on an ATM PVC, PVC range, VC class, or Ethernet subinterface.
Benefits
The PPPoE Session Limit feature prevents the router from using too much memory for virtual access by enabling you to limit the number of PPPoE sessions that can be created on a router or on an ATM PVC, PVC range, VC class, or Ethernet subinterface.
Related Documents
•Cisco IOS Security Configuration Guide, Release 12.2
•Cisco IOS Security Command Reference, Release 12.2
•ATM PVC Range and Routed Bridge Encapsulation Subinterface Grouping, Cisco IOS Release 12.1(5)T feature module
•PPPoE on ATM, Cisco IOS Release 12.1(1)T feature module
•PPPoE on Ethernet, Cisco IOS Release 12.1(2)T feature module
Supported Platforms
•Cisco 7200 series
•Cisco 7401 ASR router
Platform Support Through Feature Navigator
Cisco IOS software is packaged in feature sets that support specific platforms. To get updated information regarding platform support for this feature, access Feature Navigator. Feature Navigator dynamically updates the list of supported platforms as new platform support is added for the feature.
Feature Navigator is a web-based tool that enables you to quickly determine which Cisco IOS software images support a specific set of features and which features are supported in a specific Cisco IOS image.
To access Feature Navigator, you must have an account on Cisco.com. If you have forgotten or lost your account information, send a blank e-mail to cco-locksmith@cisco.com. An automatic check will verify that your e-mail address is registered with Cisco.com. If the check is successful, account details with a new random password will be e-mailed to you. Qualified users can establish an account on Cisco.com by following the directions at http://www.cisco.com/register.
Feature Navigator is updated when major Cisco IOS software releases and technology releases occur. As of May 2001, Feature Navigator supports M, T, E, S, and ST releases. You can access Feature Navigator at the following URL:
http://www.cisco.com/go/fn
Supported Standards, MIBs, and RFCs
Standards
No new or modified standards are supported by this feature.
MIBs
No new or modified MIBs are supported by this feature.
To obtain lists of supported MIBs by platform and Cisco IOS release, and to download MIB modules, go to the Cisco MIB website on Cisco.com at the following URL:
http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml
RFCs
No new or modified RFCs are supported by this feature.
Configuration Tasks
To configure PPPoE session limits, complete one or more of the following tasks.
•Limiting the Number of PPPoE Sessions on the Router (optional)
•Limiting the Number of PPPoE Sessions on a PVC (optional)
•Limiting the Number of PPPoE Sessions in a VC Class (optional)
•Limiting the Number of PPPoE Sessions in an ATM PVC Range (optional)
•Limiting the Number of PPPoE Sessions on an Individual PVC Within a PVC Range (optional)
To verify PPPoE sessions limits, complete the following task:
•Verifying PPPoE Session Limits (optional)
Limiting the Number of PPPoE Sessions on the Router
To specify the maximum number of PPPoE sessions that can be created on a router, use the following command in VPDN group configuration mode:
PPPoE session limits configured using the pppoe limit max-sessions command take precedence over limits configured using the pppoe limit per-vlan and pppoe limit per-mac commands.
Limiting the Number of PPPoE Sessions on a PVC
To specify the maximum number of PPPoE sessions that can be created on a PVC, use the following command in interface-ATM-VC configuration mode:
PPPoE session limits created on a PVC using the pppoe max-sessions command take precedence over the limits created with the pppoe limit per-vc command.
PPPoE session limits created on a PVC take precedence over limits created in a VC class or ATM PVC range.
Limiting the Number of PPPoE Sessions in a VC Class
To specify the maximum number of PPPoE sessions that can be created in a VC class, use the following command in VC-class configuration mode:
PPPoE session limits created in a VC class using the pppoe max-sessions command take precedence over the limits created with the pppoe limit per-vc command.
PPPoE session limits created on a PVC and ATM PVC range take precedence over limits created in a VC class.
Limiting the Number of PPPoE Sessions in an ATM PVC Range
To specify the maximum number of PPPoE sessions that can be created in an ATM PVC range, use the following command in ATM PVC range configuration mode:
PPPoE session limits created in an ATM PVC range using the pppoe max-sessions command take precedence over the limits created with the pppoe limit per-vc command.
PPPoE session limits created in an ATM PVC range take precedence over limits created in a VC class.
Limiting the Number of PPPoE Sessions on an Individual PVC Within a PVC Range
To specify the maximum number of PPPoE sessions that can be created on an individual PVC within a PVC range, use the following command in ATM PVC-in-range configuration mode:
PPPoE session limits created on an individual PVC within a range using the pppoe max-sessions command take precedence over the limits created with the pppoe limit per-vc command.
PPPoE session limits created on an individual PVC within a range take precedence over limits created in a VC class or ATM PVC range.
Verifying PPPoE Session Limits
To verify that PPPoE session limits are configured correctly, use the following command in privileged EXEC mode:
Monitoring and Maintaining PPPoE Session Limits
To monitor PPPoE session limits, use the following command in EXEC mode:
Command PurposeRouter# debug vpdn pppoe-errors
Displays PPPoE protocol errors that prevent a session from being established or errors that cause an established session to be closed.
Configuration Examples
This section provides the following configuration examples:
•Limiting the Number of PPPoE Sessions on the Router Example
•Limiting the Number of PPPoE Sessions on a PVC Example
•Limiting the Number of PPPoE Sessions in a VC Class Example
•Limiting the Number of PPPoE Sessions in an ATM PVC Range Example
•Limiting the Number of PPPoE Sessions on an Individual PVC Within a PVC Range Example
Limiting the Number of PPPoE Sessions on the Router Example
The following example shows a limit of 100 PPPoE sessions configured for the router.
Router(config)# vpdn enableRouter(config-vpdn)# vpdn-group 1Router(config-vpdn)# accept dialinRouter(config-vpdn-acc-in)# protocol pppoeRouter(config-vpdn-acc-in)# virtual-template 1Router(config-vpdn-acc-in)# exitRouter(config-vpdn)# pppoe limit max-sessions 100Limiting the Number of PPPoE Sessions on a PVC Example
The following example shows a limit of 10 PPPoE sessions configured for the PVC.
Router(config)# interface ATM1/0.102 multipointRouter(config-if)# pvc 3/304Router(config-if-atm-vc)# encapsulation aal5snapRouter(config-if-atm-vc)# protocol pppoeRouter(config-if-atm-vc)# pppoe max-sessions 10Limiting the Number of PPPoE Sessions in a VC Class Example
The following example shows a limit of 20 PPPoE sessions configured for the VC class called "main."
Router(config)# vc-class atm mainRouter(config-vc-class)# pppoe max-sessions 20Limiting the Number of PPPoE Sessions in an ATM PVC Range Example
The following example shows a limit of 30 PPPoE sessions configured for the ATM PVC range called "range-1."
Router(config)# interface atm 6/0.110 multipointRouter(config-subif)# range range-1 pvc 100 4/199Router(config-if-atm-range)# encapsulation aal5snapRouter(config-if-atm-range)# protocol ppp virtual-template 2Router(config-if-atm-range)# pppoe max-sessions 30Limiting the Number of PPPoE Sessions on an Individual PVC Within a PVC Range Example
The following example shows a limit of 10 PPPoE sessions configured for "pvc1," which is part of the ATM PVC range called "range1."
Router(config)# interface atm 6/0.110 multipointRouter(config-subif)# range range1 pvc 100 4/199Router(cfg-if-atm-range-pvc)# pvc-in-range pvc1 3/104Router(cfg-if-atm-range-pvc)# pppoe max-sessions 10Command Reference
This section documents new or modified commands. All other commands used with this feature are documented in the Cisco IOS Release 12.2 command reference publications.
pppoe limit max-sessions
To specify the maximum number of PPPoE sessions that will be permitted on a router, use the pppoe limit max-sessions command in VPDN group configuration mode. To remove this specification, use the no form of this command.
pppoe limit max-sessions number-of-sessions
no pppoe limit max-sessions
Syntax Description
number-of-sessions
Maximum number of PPPoE sessions that will be permitted on the router. The range is from 0 to the maximum number of interfaces on the router.
Defaults
There is no default number-of-sessions.
Command Modes
VPDN group configuration
Command History
Release Modification12.2(1)DX
This command was introduced.
12.2(2)DD
This command was integrated into Cisco IOS Release 12.2(2)DD.
Usage Guidelines
PPPoE session limits configured using the pppoe limit per-vc, pppoe limit per-vlan, and pppoe max-sessions, pppoe max-sessions (VC), and pppoe max-sessions (subinterface) commands will take precedence over limits configured for the router using the pppoe limit max-sessions command.
Examples
The following example shows a limit of 100 PPPoE sessions configured for the router.
vpdn enablevpdn-group 1accept dialinprotocol pppoevirtual-template 1pppoe limit max-sessions 100Related Commands
pppoe max-sessions
To specify the maximum number of PPPoE sessions that will be permitted on an ATM PVC, PVC range, VC class, or Ethernet subinterface, use the pppoe max-sessions command in the appropriate command mode. To remove this specification, use the no form of this command.
pppoe max-sessions number-of-sessions
no pppoe max-sessions
Syntax Description
Defaults
100 sessions
Command Modes
Ethernet subinterface configuration
Interface-ATM-VC configuration
VC-class configuration
ATM PVC range configuration
PVC-in-range configurationCommand History
Usage Guidelines
PPPoE session limits configured on an Ethernet subinterface using the pppoe max-sessions command take precedence over limits configured by using the pppoe limit per-vlan and pppoe limit per-mac commands.
PPPoE session limits configured on a VC by using the pppoe max-sessions command take precedence over the limits created with the pppoe limit per-vc command.
PPPoE session limits created on an ATM PVC take precedence over limits created in a VC class or ATM PVC range.
PPPoE session limits created in an ATM PVC range take precedence over limits created in a VC class.
Examples
Ethernet Subinterface Example
The following example shows a limit of 200 PPPoE sessions configured for the subinterface:
interface FastEthernet 0/0.10encapsulation dot1Q 10pppoe enablepppoe max-sessions 200ATM PVC Example
The following example shows a limit of 10 PPPoE sessions configured for the PVC:
interface ATM1/0.102 multipointpvc 3/304encapsulation aal5snapprotocol pppoepppoe max-sessions 10VC Class Example
The following example shows a limit of 20 PPPoE sessions configured for the VC class called "main."
vc-class atm mainpppoe max-sessions 20ATM PVC Range Example
The following example shows a limit of 30 PPPoE sessions configured for the ATM PVC range called "range-1."
interface atm 6/0.110 multipointrange range-1 pvc 100 4/199encapsulation aal5snapprotocol ppp virtual-template 2pppoe max-sessions 30Individual PVC Within a PVC Range Example
The following example shows a limit of 10 PPPoE sessions configured for "pvc1," which is part of the ATM PVC range called "range1."
interface atm 6/0.110 multipointrange range1 pvc 100 4/199pvc-in-range pvc1 3/104pppoe max-sessions 10Related Commands