Troubleshooting ISG with Session Monitoring and Distributed Conditional Debugging

Intelligent Services Gateway (ISG) is a software feature set that provides a structured framework in which edge devices can deliver flexible and scalable services to subscribers.This document describes ISG session monitoring and distributed conditional debugging. Conditional debugging facilitates debug filtering for ISG and is available as distributed conditional debugging.

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.

Prerequisites for ISG Session Monitoring and Distributed Conditional Debugging

Before using the information in this module, it is recommended that you be familiar with the use of Cisco IOS debug commands and conditional debugging. See the "Additional References" section to find information about these topics.

Restrictions for Distributed Conditional Debugging

Conditions that are set for an active session take effect only when the session is terminated and reestablished.


Caution

Because debugging output is assigned high priority in the CPU process, it can render the system unusable. For this reason, use the Cisco IOS debugcommands only to troubleshoot specific problems or during troubleshooting sessions with Cisco technical support staff. Moreover, it is best to use debug commands during periods of lower network traffic and fewer users, or on a debug chassis with a single active session. Debugging during these periods decreases the likelihood that increased debug command processing overhead will affect system use.

Information About ISG Session Monitoring and Distributed Conditional Debugging

ISG Session and Flow Monitoring

ISG introduces a mechanism that allows an administrator to monitor ISG sessions and flows continuously. The show interface monitor command, which displays interface statistics, and the show process cpu monitor command, which displays information about CPU usage, both update the information in their displays at specified intervals. These commands also provide the ability to freeze or clear the information in the display.

ISG Distributed Conditional Debugging

Benefits of Enhanced Conditional Debugging for the ISG Platforms

Because thousands of user sessions run on the ISG platforms, it is not practical to troubleshoot a problem with a session by enabling the various component debug commands that are available and trace through the messages for a single session or user. Instead, it is more practical to filter debugging messages for a single session or call across the various components that a session traverses. For this reason, the conditional debugging previously offered in the software has been enhanced to facilitate debug filtering for ISG and is available as distributed conditional debugging.

Cisco IOS XE Software Components Supported by Distributed Conditional Debugging

The following components are supported for ISG distributed conditional debugging:

  • Authentication, authorization, and accounting (AAA) and RADIUS

  • Feature Manager

  • Policy Manager

  • PPP

  • PPP over Ethernet (PPPoE)

  • Session Manager

  • Virtual Private Dialup Network (VPDN)

See Table 1 and Table 2 for specific commands that are supported for distributed conditional debugging.

How to Enable ISG Session Monitoring and Distributed Conditional Debugging

Monitoring ISG Sessions and Flows

Perform this task to monitor interface and CPU statistics. The show commands are not required and may be entered in any order.

SUMMARY STEPS

    1.    enable

    2.    show interface type number monitor [interval seconds]

    3.    show processes cpu monitor [interval seconds]


DETAILED STEPS
     Command or ActionPurpose
    Step 1 enable


    Example:
    Router> enable
     

    Enables privileged EXEC mode.

    • Enter your password if prompted.

     
    Step 2 show interface type number monitor [interval seconds]


    Example:
    Router# show interface gigabitethernet 3/0/0 monitor interval 10
     

    Displays interface statistics that are updated at specified intervals.

     
    Step 3 show processes cpu monitor [interval seconds]


    Example:
    Router# show processes cpu monitor
     

    Displays detailed CPU utilization statistics that are updated at specified intervals.

     

    Configuring Distributed Conditional Debugging

    Two main tasks are required for configuring distributed conditional debugging: enabling conditional debugging, and issuing one or more supported debug commands. These required tasks are described in the following sections:

    ISG Debug Condition Commands

    The table below lists the debug condition commands that you can issue at the EXEC prompt to enable distributed conditional debugging. You can set more than one condition.

    Table 1 Supported Conditional Debug Commands

    Command

    Purpose

    debug condition domain domain-name

    Filters messages on the specified domain name.

    debug condition interface {Fast Ethernet | Gigabit Ethernet | TenGigabit Ethernet} vlan-id ID

    Filters messages on the specified VLAN identifier.

    debug condition mac-address hexadecimal-MAC-address

    Filters messages on the specified MAC address.

    debug condition portbundle ip IP-address bundle bundle-number

    Filters messages on the specified Port-Bundle Host Key (PBHK).

    debug condition session-id session-ID

    Filters messages on the specified session identifier.

    Note   

    The session identifier can be obtained by entering the show subscriber session command.

    debug condition username email-address

    Filters messages on the specified Internet username.

    Debug Commands That Are Supported by ISG Conditional Debug

    The table below lists the Cisco IOS debugging commands that are supported for distributed conditional debugging. The commands are listed by component. One or more of these commands can be issued after enabling one of the debug condition commands listed in Debug Commands That Are Supported by ISG Conditional Debug.

    Table 2 Debug Commands Supported by ISG Distributed Conditional Debugging

    AAA Debug Commands

    debug aaa accounting

    debug aaa authentication

    debug aaa authorization

    debug aaa id

    PPP Debug Commands

    debug ppp authentication

    debug ppp bap error

    debug ppp bap events

    debug ppp bap negotiation

    debug ppp cbcp

    debug ppp error

    debug ppp mppe detailed

    debug ppp mppe events

    debug ppp mppe pack

    debug ppp multi data

    debug ppp multi events

    debug ppp multi frag

    debug ppp negotiation

    debug ppp pack

    debug ppp subscriber

    PPPoE Debug Commands

    debug pppoe data

    debug pppoe error

    debug pppoe event

    debug pppoe packet

    Session Manager Debug Commands

    debug subscriber aaa authorization event

    debug subscriber aaa authorization fsm

    debug subscriber error

    debug subscriber event

    Feature Manager Debug Commands

    debug subscriber feature access-list error

    debug subscriber feature access-list event

    debug subscriber feature compression detail

    debug subscriber feature compression error

    debug subscriber feature compression event

    debug subscriber feature detail

    debug subscriber feature error

    debug subscriber feature event

    debug subscriber feature interface-config error

    debug subscriber feature interface-config event

    debug subscriber feature modem-on-hold detail

    debug subscriber feature modem-on-hold error

    debug subscriber feature modem-on-hold event

    debug subscriber feature portbundle error

    debug subscriber feature portbundle event

    debug subscriber feature portbundle packet

    debug subscriber feature qos-policy error

    debug subscriber feature qos-policy event

    debug subscriber feature static-routes error

    debug subscriber feature static-routes event

    debug subscriber feature traffic-classification detail

    debug subscriber feature traffic-classification error

    debug subscriber feature traffic-classification event

    Policy Manager Debug Commands

    debug subscriber fsm

    debug subscriber policy condition

    debug subscriber policy detail

    debug subscriber policy error

    debug subscriber policy event

    debug subscriber policy fsm

    debug subscriber policy rule

    debug subscriber session error

    debug subscriber session event

    VPDN Debug Commands

    debug vpdn call event

    debug vpdn call fsm

    debug vpdn error

    debug vpdn event

    debug vpdn event disconnect

    Restrictions

    The debug condition session-id command filters a session only after the session has been established. The session identifier is a unique dynamic number generated internally by the Cisco IOS software and assigned to each session when the session is established.

    In VPDN, the debug commands and messages associated with tunnels cannot be filtered because they are not associated with a session, but are displayed during the tunnel-establishment phase. The debugging messages will be displayed even if filtering is enabled by one of the conditions.

    If multiple conditions are set, the debugging messages corresponding to all the sessions that meet any of the conditions will be displayed. Some conditions, such as domain name, will trigger debugging messages for all the sessions that belong to the particular domain.

    Enabling Distributed Conditional Debugging

    Perform this task to enable distributed conditional debugging for ISG.

    SUMMARY STEPS

      1.    enable

      2.    debug condition command

      3.    debug command


    DETAILED STEPS
       Command or ActionPurpose
      Step 1 enable


      Example:
      Router> enable
       

      Enables privileged EXEC mode.

      • Enter your password if prompted.

       
      Step 2 debug condition command


      Example:
      Router# debug condition username user@cisco.com
       

      Enter one or more of the debug condition commands listed in Enabling Distributed Conditional Debugging to enable distributed conditional debugging.

       
      Step 3 debug command


      Example:
      Router# debug subscriber aaa authorization fsm
       

      Enter one or more of the supported debug commands from Enabling Distributed Conditional Debugging.

       

      Displaying Debugging Conditions

      To display the debugging conditions that have been set, perform the following task:

      SUMMARY STEPS

        1.    enable

        2.    show debug condition


      DETAILED STEPS
         Command or ActionPurpose
        Step 1 enable


        Example:
        Router> enable
         

        Enables privileged EXEC mode.

        • Enter your password if prompted.

         
        Step 2 show debug condition


        Example:
        Router# show debug condition
         

        Displays conditions that have been set for debugging.

         

        Troubleshooting Tips

        The Cisco IOS software displays messages as you set the conditions for filtering the debugging.

        When a condition is set, it is assigned a number, as follows:

        Condition 1 set

        If a condition has already been set, the following message is displayed:

        % Condition already set

        The following messages and prompt are displayed when you attempt to disable the last condition using the no form of a debug condition command:

        This condition is the last interface condition set.
Removing all conditions may cause a flood of debugging messages
to result, unless specific debugging flags are first removed.
Proceed with removal? [yes/no]: yes
Condition 1 has been removed

        Tip

        Use the no form of the commands to disable all debug commands before disabling all of the debugging conditions that have been set.

        Configuration Examples for ISG Distributed Conditional Debugging

        Monitoring Interface Statistics Example

        The following example shows sample output for the show interface monitor command. The display will be updated every 10 seconds.

        Router> show interface gigabitethernet 0/0/0 monitor interval 10
Router Name:  Scale3-Router8       Update Secs: 10
Interface Name:   GigabitEthernet 0/0/0 Interface Status: UP, line is up 
Line Statistics:          Total:        Rate(/s)    Delta
Input Bytes:              123456        123         7890
Input Packets:              3456         56          560
Broadcast:                  1333          6           60
OutputBytes:               75717        123         1230
Output Packets:              733         44          440
Error Statistics:         Total:        Delta:
Input Errors:              0               0
CRC  Errors:               0               0
Frame Errors:              0               0
Ignored:                   0               0
Output Errors:             0               0
Collisions:                0               0
No. Interface Resets:  2
End = e       Clear = c      Freeze = f

        Enter Command:

        Monitoring CPU Statistics Example

        The following example shows sample output for the show processes cpu monitor command:

        Router> show processes cpu monitor
 
CPU utilization for five seconds: 0%/0%; one minute: 0%; five minutes: 0%
 PID Runtime(ms)   Invoked      uSecs    5Sec   1Min     5Min    TTY Process 
   3      772          712       1084    0.08%  0.04%    0.02%    0    Exec             
  67      276         4151         66    0.08%  0.03%    0.01%    0 L2TP mgmt daemon 
 116      604         2263        266    0.16%  0.05%    0.01%    0 IDMGR CORE       
 
End = e    Freeze = f

        Enter Command:

        Enabling ISG Distributed Conditional Debugging Example

        The following example shows how to filter PPP, PPPoE, and Session Manager debugs for a PPPoE session with username “user@cisco.com”. Only debugging messages for the defined user are displayed on the console. Any other debugging messages associated with other users will not be displayed.

        Router# debug condition username user@cisco.com
Condition 1 set
 
Router# debug ppp negotiation
Router# debug pppoe event
Router# debug subscriber session event

        Displaying Debugging Conditions Example

        The following example shows how to display debugging conditions that have been set.

        Router# show debug condition

Condition 1: domain cisco.com (0 flags triggered)
Condition 2: username user@cisco.com (0 flags triggered)
Condition 3: ip 172.19.200.10 (0 flags triggered)

        Filtering Debug Output Example

        In the following example, the output of the debug subscriber packet detail command is filtered on the basis of the username “cpe6_1@isp.com”: 

        Router# debug condition username cpe6_1@isp.com
Condition 1 set
Router# show debug
 
Condition 1: username cpe6_1@isp.com (0 flags triggered)
 
Router# debug subscriber packet detail
SSS packet detail debugging is on

Router# show debug
SSS:
  SSS packet detail debugging is on
 
Condition 1: username cpe6_1@isp.com (0 flags triggered)

        Additional References

        Related Documents

        Related Topic

        Document Title

        ISG commands

        Cisco IOS Intelligent Services Gateway Command Reference

        Debug commands

        Cisco IOS Debug Command Reference

        Conditional debugging

        "Conditionally Triggered Debugging" chapter in the Cisco IOS Debug Command Reference

        Technical Assistance

        Description

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        Feature Information for Distributed Conditional Debugging

        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 3 Feature Information for ISG Session Monitoring and Distributed Conditional Debugging

        Feature Name

        Releases

        Feature Configuration Information

        ISG: Instrumentation: Session and Flow Monitoring

        Cisco IOS XE Release 2.2

        ISG provides a mechanism for continuously monitoring interface and CPU statistics. This feature introduces the show interface monitor and show processes cpu monitorcommands, which display statistics that are updated at specified intervals.

        ISG: Instrumentation: Advanced Conditional Debugging

        Cisco IOS XE Release 2.2

        ISG provides the ability to define various conditions for filtering debug output. Conditional debugging generates very specific and relevant information that can be used for session, flow, subscriber, and service diagnostics.