The PPPoE Session Count Management Information Base feature provides the ability to use Simple Network Management Protocol (SNMP) to monitor in real time the number of PPP over Ethernet (PPPoE) sessions configured on permanent virtual circuits (PVCs) and on a router.
This MIB also supports two SNMP traps that generate notification messages when a PPPoE session-count threshold is reached on any PVC or on the router. The PPPoE session-count thresholds can be configured using the
sessionsmaxlimitand
pppoemax-sessionscommands.
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 Monitoring PPPoE Sessions with SNMP
You must understand the
concepts described in the "Preparing for Broadband Access Aggregation" module.
PPPoE sessions must be
established using the procedures in the "Providing Protocol Support for
Broadband Access Aggregation of PPPoE Sessions" module.
Restrictions for Monitoring PPPoE Sessions with SNMP
The snmp-serverenabletrapspppoe command enables SNMP traps only. It does not support inform requests.
Information About Monitoring PPPoE Sessions with SNMP
SNMP is a network management protocol used almost exclusively in TCP/IP networks. SNMP provides a means to monitor and control network devices and to manage configurations, statistics collection, performance, and security. SNMP version 2 supports centralized and distributed network management strategies and includes improvements in the Structure of Management Information (SMI), protocol operations, management architecture, and security.
PPPoE Session Count MIB
Note
Effective with Cisco IOS Release 12.2(28)SB, the
pppoelimitmax-sessionscommand is replaced by the
sessionsmaxlimitcommand in BBA group configuration mode. See the
sessionsmaxlimitcommand for more information.
A MIB is a database of network management information that is used and
maintained by a network management protocol, such as SNMP. The value of a MIB
object can be changed or retrieved using SNMP commands, usually through a
network management system.
The PPPoE Session Count MIB uses two SNMP traps that generate
notification messages when a PPPoE session-count threshold is reached on any
PVC or on the router. The PPPoE session-count thresholds can be configured
using the
pppoelimitmax-sessions and
pppoemax-sessions commands.
The table below describes the objects and tables supported by the PPPoE
Session-Count MIB. For a complete description of the MIB, see the PPPoE
Sessions Management MIB file CISCO-PPPOE-MIB.my, available through Cisco.com at
the following URL:
http://www.cisco.com/go/mibs .
Table 1
PPPoE Session Count MIB Objects and Tables
Object or Table
Description
cPppoeSystemCurrSessions
Number of PPPoE sessions active on the router.
cPppoeSystemHighWaterSessions
Total number of PPPoE sessions configured on the router since
the system was initialized.
cPppoeSystemMaxAllowedSessions
Number of PPPoE sessions that can be configured on the router.
cPppoeSystemThresholdSessions
Threshold value of PPPoE sessions that can be configured on the
router.
cPppoeSystemExceededSessionErrors
Accumulated number of errors on the router that have occurred
because the cPppoeSystemCurrSessions value exceeded the
cPppoeSystemMaxAllowedSessions value.
cPppoeVcCfgTable
PPPoE protocol-related configuration information about the
virtual channel links (VCLs).
cPppoeVcSessionsTable
Configuration information and statistics about the number of
PPPoE sessions on the VCLs.
cPppoeSystemSessionThresholdTrap
Generates a notification message when the number of PPPoE
sessions on the router reaches the configured threshold value.
cPppoeVcSessionThresholdTrap
Generates a notification message when the number of PPPoE
sessions on the PVC reaches the configured threshold value.
Benefits of Monitoring PPPoE Sessions with SNMP
The monitoring of PPPoE sessions with SNMP provides the following benefits:
It helps manage the number of PPPoE sessions configured on a router or PVC by sending notification messages when the PPPoE session threshold has been reached.
It provides a way of tracking PPPoE session information over time.
How to Configure SNMP Monitoring of PPPoE Sessions
Perform this task to enable SNMP traps that send notification messages when PPPoE session thresholds have been reached.
SUMMARY STEPS
1.enable
2.configureterminal
3.snmp-serverenabletrapspppoe
4.exit
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
snmp-serverenabletrapspppoe
Example:
Router(config)# snmp-server enable traps pppoe
Enables PPPoE session count SNMP notifications.
Step 4
exit
Example:
Router(config)# exit
Exits global configuration mode and returns to privileged EXEC mode.
Configuring the PPPoE Session-Count Threshold for the Router Using VPDN Groups
Note
Effective with Cisco IOS Release 12.2(28)SB, the pppoelimitmax-sessionscommand is replaced by the sessionsmaxlimitcommand in BBA group configuration mode. See the sessionsmaxlimit command for more information.
Perform this task to configure the PPPoE session-count threshold for the router using VPDN groups.
Sets the maximum number of PPPoE sessions that will be permitted on a router, and sets the PPPoE session-count threshold at which an SNMP trap will be generated.
Step 8
exit
Example:
Router(config-vpdn-acc-in)# exit
Exits VPDN dialin access configuration mode and returns to VPDN group configuration mode.
Configuring the PPPoE Session-Count Threshold for the Router Using BBA Groups
Perform this task to configure the PPPoE session-count threshold for the router using BBA groups.
Router(config-bba-group)# sessions max limit 4000 threshold 3000
Sets the maximum number of PPPoE sessions that will be permitted on a router, and sets the PPPoE session-count threshold at which an SNMP trap will be generated.
Step 6
exit
Example:
Router(config-bba-group)# exit
Exits BBA group configuration mode and returns to global configuration mode.
Configuring the PPPoE Session-Count Threshold for a PVC
Perform this task to configure the PPPoE session-count threshold for
a PVC.
Sets the maximum number of PPPoE sessions that will be permitted
on an ATM PVC, PVC range, VC class, or VLAN, and sets the PPPoE session-count
threshold at which an SNMP trap will be generated.
Step 6
exit
Example:
Router(config-if-atm-vc)# exit
Exits ATM virtual circuit configuration mode and returns to
interface configuration mode.
Configuring the PPPoE Session-Count Threshold for a VC Class
Perform this task to configure the PPPoE session-count threshold for
a VC class.
Sets the maximum number of PPPoE sessions that will be permitted
on an ATM PVC, PVC range, VC class, or VLAN, and sets the PPPoE session-count
threshold at which an SNMP trap will be generated.
Step 5
exit
Example:
Router(config-vc-class)# exit
Exits ATM VC class configuration mode and returns to global
configuration mode.
Configuring the PPPoE Session-Count Threshold for an ATM PVC Range
Sets the maximum number of PPPoE sessions that will be permitted
on an ATM PVC, PVC range, VC class, or VLAN, and sets the PPPoE session-count
threshold at which an SNMP trap will be generated.
Step 6
exit
Example:
Router(config-if-atm-range)# exit
Exits ATM PVC range configuration mode and returns to global
configuration mode.
Configuring the PPPoE Session-Count Threshold for an Individual PVC Within a Range
Perform this task to configure the PPPoE session-count threshold for
an individual PVC within an ATM PVC range.
Sets the maximum number of PPPoE sessions that will be permitted
on an ATM PVC, PVC range, VC class, or VLAN, and sets the PPPoE session-count
threshold at which an SNMP trap will be generated.
Step 7
exit
Example:
Router(config-if-atm-range-pvc)# exit
Exits ATM PVC in-range configuration mode and returns to ATM PVC
range configuration mode.
Verifying PPPoE Session-Count Thresholds
Use the following task to verify PPPoE session-count thresholds:
SUMMARY STEPS
1.enable
2.moresystem:runningconfig
DETAILED STEPS
Step 1
enable
Use this command to enable privileged EXEC mode. Enter your password when prompted.
Example:
Router> enable
Step 2
moresystem:runningconfig
Use this command to display the running configuration.
Example:
Router# more system:running config
Building configuration...
Current configuration:
!
version 12.3
no service udp-small-servers
no service tcp-small-servers
!
hostname Router2
!
.
.
.
!
end
Monitoring and Maintaining PPPoE Session Counts and SNMP Notifications
Perform the following task to monitor PPPoE sessions counts and SNMP notifications:
Use this command to enable privileged EXEC mode. Enter your password when prompted.
Example:
Router> enable
Step 2
debugsnmppackets
Use this command to display information about every SNMP packet sent or received by the router:
Example:
Router# debug snmp packets
SNMP: Packet received via UDP from 172.16.63.17 on Ethernet0
SNMP: Get-next request, reqid 23584, errstat 0, erridx 0
sysUpTime = NULL TYPE/VALUE
system.1 = NULL TYPE/VALUE
system.6 = NULL TYPE/VALUE
SNMP: Response, reqid 23584, errstat 0, erridx 0
sysUpTime.0 = 2217027
system.1.0 = Cisco Internetwork Operating System Software
system.6.0 =
SNMP: Packet sent via UDP to 172.16.63.17
Step 3
debugpppoeerrorsinterfaceatminterface-number
Use this command to display PPPoE protocol errors that prevent a session from being established or errors that cause an established session to be closed:
Example:
Router# debug pppoe errors interface atm 1/0.10
PPPoE protocol errors debugging is on
Router#
00:44:30:PPPoE 0:Max session count(1) on mac(00b0.c2e9.c470) reached.
00:44:30:PPPoE 0:Over limit or Resource low. R:00b0.c2e9.c470 L:ffff.ffff.ffff 0/101
ATM1/0.10
Configuring PPPoE Session-Count SNMP Traps Example
The following example shows how to enable the router to send PPPoE session-count SNMP notifications to the host at the address 10.64.131.20:
snmp-server community public RW
snmp-server enable traps pppoe
snmp-server host 10.64.131.20 version 2c public udp-port 1717
PPPoE Session-Count Threshold for the Router Example
Note
Effective with Cisco IOS Release 12.2(28)SB, the
pppoelimitmax-sessionscommand is replaced by the
sessionsmaxlimitcommand in BBA group configuration mode. See the
sessionsmaxlimit command for more information.
The following example shows a limit of 4000 PPPoE sessions configured
for the router through VPDN groups. The PPPoE session-count threshold is set at
3000 sessions, so when the number of PPPoE sessions on the router reaches 3000,
an SNMP trap will be generated.
The following example shows a limit of 4000 PPPoE sessions configured
for the router through BBA groups. The PPPoE session-count threshold is set at
3000 sessions, so when the number of PPPoE sessions on the router reaches 3000,
an SNMP trap will be generated.
bba-group pppoe global
virtual-template 1
sessions max limit 4000 threshold 3000
PPPoE Session-Count Threshold for a PVC Example
The following example shows a limit of five PPPoE sessions configured for the PVC. The PPPoE session-count threshold is set at three sessions, so when the number of PPPoE sessions on the PVC reaches three, an SNMP trap will be generated.
interface ATM 0/0/0
ip address 10.0.0.1 255.255.255.0
no atm ilmi-keepalive
pvc 5/120
protocol ip 10.0.0.2 broadcast
pppoe max-sessions 5 threshold-sessions 3
protocol pppoe
PPPoE Session-Count Threshold for a VC Class Example
The following example shows a limit of seven PPPoE sessions configured for a VC class called "main." The PPPoE session-count threshold is set at three sessions, so when the number of PPPoE sessions for the VC class reaches three, an SNMP trap will be generated.
vc-class atm main
pppoe max-sessions 7 threshold-sessions 3
PPPoE Session-Count Threshold for a PVC Range Example
The following example shows a limit of 20 PPPoE sessions configured for
the PVC range. The PPPoE session-count threshold will also be 20 sessions
because when the session-count threshold has not been explicitly configured, it
defaults to the PPPoE session limit. An SNMP trap will be generated when the
number of PPPoE sessions for the range reaches 20.
PPPoE Session-Count Threshold for an Individual PVC Within a PVC Range Example
The following example shows a limit of ten PPPoE sessions configured for pvc1. The PPPoE session-count threshold is set at three sessions, so when the number of PPPoE sessions for the PVC reaches three, an SNMP trap will be generated.
If you want to establish PPPoE session limits for sessions on a specific PVC or VLAN configured on an L2TP access concentrator, refer to the "Establishing PPPoE Session Limits per NAS Port" module.
If you want to use service tags to enable a PPPoE server to offer PPPoE clients a selection of service during call setup, refer to the "Offering PPPoE Clients a Selection of Services During Call Setup" module.
If you want to enable an L2TP access concentrator to relay active discovery and service selection functionality for PPPoE over an L2TP control channel to a LNS or tunnel switch, refer to the "Enabling PPPoE Relay Discovery and Service Selection Functionality" module.
If you want to configure the transfer upstream of the PPPoX session speed value, refer to the "Configuring Upstream Connection Speed Transfer" module.
If you want to identify a physical subscriber line for RADIUS communication with a RADIUS server, refer to the "Identifying the Physical Subscriber Line for RADIUS Access and Accounting" module.
If you want to configure a Cisco Subscriber Service Switch, refer to the "Configuring Cisco Subscriber Service Switch Policies" module.
Additional References
The following sections provide references related to monitoring PPPoE sessions with SNMP.
Related Documents
Related Topic
Document Title
Broadband access aggregation concepts
Understanding Broadband Access Aggregation
Tasks for preparing for broadband access aggregation
Preparing for Broadband Access Aggregation
Configuring PPPoE sessions
Providing Protocol Support for Broadband Access Aggregation of PPPoE Sessions
Establishing PPPoE session limits for sessions on a specific PVC or VLAN configured on an L2TP access concentrator
Establishing PPPoE Session Limits per NAS Port
Using service tags to enable a PPPoE server to offer PPPoE clients a selection of service during call setup
Offering PPPoE Clients a Selection of Services During Call Setup
Enabling an L2TP access concentrator to relay active discovery and service selection functionality for PPPoE over an L2TP control channel to a LNS or tunnel switch
Enabling PPPoE Relay Discovery and Service Selection Functionality
Configuring the transfer upstream of the PPPoX session speed value
Configuring Upstream Connection Speed Transfer
Identifying a physical subscriber line for RADIUS communication with a RADIUS server
Identifying the Physical Subscriber Line for RADIUS Access and Accounting
Configuring a Cisco Subscriber Service Switch
Configuring Cisco Subscriber Service Switch Policies
Standards
Standards
Title
None
--
MIBs
MIBs
MIBs Link
PPPoE Session Count MIB
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Feature Information for Monitoring PPPoE Sessions with SNMP
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 2
Feature Information for Monitoring PPPoE Sessions with SNMP
Feature Name
Releases
Feature Configuration Information
PPPoE Session Count MIB
12.2(1)DC 12.2(8)T 12.2(33)SRC
This feature provides the ability to use Simple Network Management Protocol (SNMP) to monitor in real time the number of PPP over Ethernet sessions configured on permanent virtual circuits (PVCs) and on a router.
The following commands were introduced or modified:
pppoelimitmax-sessions,
pppoemax-sessions,
sessionsmaxlimit.
Glossary
ATM--Asynchronous Transfer Mode. The international standard for cell relay in which multiple service types (such as voice, video, or data) are conveyed in fixed-length (53-byte) cells. Fixed-length cells allow cell processing to occur in hardware, thereby reducing transit delays. ATM is designed to take advantage of high-speed transmission media, such as E3, SONET, and T3.
MIB--Management Information Base. Database of network management information that is used and maintained by a network management protocol such as SNMP. The value of a MIB object can be changed or retrieved using SNMP commands, usually through a network management system (NMS). MIB objects are organized in a tree structure that includes public (standard) and private (proprietary) branches.
PVC--Permanent Virtual Circuit. Virtual circuit that is permanently established. PVCs save bandwidth associated with circuit establishment and teardown in situations where certain virtual circuits must exist all the time. In ATM terminology, PVC also stands for permanent virtual connection.
SNMP--Simple Network Management Protocol. An application-layer protocol that provides a message format for communication between SNMP managers and agents and is exclusively used in TCP/IP networks. SNMP provides a means to monitor and control network devices and to manage configurations, statistics collection, performance, and security.
trap--A message from an SNMP agent alerting the SNMP manager to a condition on the network.
VCI--Virtual Channel Identifier. 16-bit field in the header of an ATM cell. The VCI, together with the VPI, is used to identify the next destination of a cell as it passes through a series of ATM switches on its way to its destination. ATM switches use the VPI/VCI fields to identify the next network VCL that a cell needs to transit on its way to its final destination.
VCL--Virtual Channel Link. Connection between two ATM devices.
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