IP SLAs Configuration Guide, Cisco IOS XE Release 3S (Cisco ASR 1000)
IP SLAs for MPLS Psuedo Wire via VCCV
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IP SLAs for MPLS Psuedo Wire via VCCV

IP SLAs for MPLS Psuedo Wire via VCCV

This module describes how to configure IP Service Level Agreements (SLAs) for MPLS Pseudo Wire (PWE3) via Virtual Circuit Connectivity Verification (VCCV) to schedule pseudo-wire ping operations and provide monitoring and alerts for round trip time (RTT), failure, and connection threshold violations via SNMP Traps.

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 at the end of this module.

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 IP SLAs for MPLS Pseudo Wire via VCCV

LSP discovery is not supported for IP SLAs VCCV operations.

Information About IP SLAs for MPLS Pseudo Wire via VCCV

IP SLAs VCCV Operation

The IP SLAs VCCV operation supports Virtual Circuit Connectivity Verification (VCCV) for Pseudo-Wire Emulation Edge-to-Edge (PWE3) services across MPLS networks. The IP SLAs VCCV operation type is based on the ping mpls pseudowire command, which checks MPLS LSP connectivity across an Any Transport over MPLS (AToM) virtual circuit (VC) by sending a series of pseudo-wire ping operations to the specified destination PE router.

When MPLS LSP connectivity checking is performed through an IP SLAs VCCV operation (rather than through the ping mpls command with the pseudowire keyword), you can use the IP SLA proactive threshold monitoring and multioperation scheduling capabilities:

The LSP discovery option does not support the IP SLAs VCCV operation.

Proactive Threshold Monitoring for the LSP Health Monitor

Proactive threshold monitoring support for the LSP Health Monitor feature provides the capability for triggering SNMP trap notifications and syslog messages when user-defined reaction conditions (such as a connection loss or timeout) are met. Configuring threshold monitoring for an LSP Health Monitor operation is similar to configuring threshold monitoring for a standard IP SLAs operation.

LSP Discovery Option Enabled

If the LSP discovery option for an LSP Health Monitor operation is enabled, SNMP trap notifications can be generated when one of the following events occurs:

  • LSP discovery for a particular BGP next hop neighbor fails.
  • Operational status of an LSP discovery group changes.

Possible reasons for which LSP discovery can fail for a particular BGP next hop neighbor are as follows:

  • Expiration of time allowed for a BGP next hop neighbor to respond to an LSP discovery request.
  • Return code is “Broken” or “Unexplorable” for all paths leading to the BGP next hop neighbor.

The table below describes the conditions for which the operational status of an LSP discovery group can change. Whenever an individual IP SLAs LSP ping operation of an LSP discovery group is executed, a return code is generated. Depending on the value of the return code and the current status of the LSP discovery group, the group status can change.

Table 1 Conditions for Which an LSP Discovery Group Status Changes

Individual IP SLAs Operation Return Code

Current Group Status = UP

Current Group Status = PARTIAL

Current Group Status = DOWN

OK

No group status change.

If return codes for all paths in the group are OK, then the group status changes to UP.

Group status changes to PARTIAL.

Broken or Unexplorable

Group status changes to PARTIAL.

If return codes for all paths in the group are Broken or Unexplorable, then the group status changes to DOWN.

No group status change.

The return code for an individual IP SLAs LSP ping operation can be one of the following:

  • OK--Indicates that the LSP is working properly. The customer VPN traffic will be sent across this path.
  • Broken--Indicates that the LSP is broken. Customer VPN traffic will not be sent across this path and may be discarded.
  • Unexplorable--Indicates that not all the paths to this PE neighbor have been discovered. This may be due to a disruption along the LSP or because the number of 127/8 IP addresses used for LSP selection has been exhausted.

The status of an LSP discovery group can be one of the following:

  • UNKNOWN--Indicates that group status has not yet been determined and that the paths belonging to the group are in the process of being tested for the first time. Once this initial test is complete, the group status will change to UP, PARTIAL, or DOWN.
  • UP--Indicates that all the paths within the group are active and no operation failures have been detected.
  • PARTIAL--Indicates that an operation failure has been detected for one or more, but not all, of the paths within the group.
  • DOWN--Indicates that an operation failure has been detected for all the paths within the group.

Secondary Frequency Option

With the introduction of the LSP Health Monitor feature, a new threshold monitoring parameter has been added that allows you to specify a secondary frequency. If the secondary frequency option is configured and a failure (such as a connection loss or timeout) is detected for a particular path, the frequency at which the path is remeasured will increase to the secondary frequency value (testing at a faster rate). When the configured reaction condition is met (such as N consecutive connection losses or N consecutive timeouts), an SNMP trap and syslog message can be sent and the measurement frequency will return to its original frequency value.

How to Configure IP SLAs for MPLS Pseudo Wire via VCCM

Manually Configuring and Scheduling an IP SLAs VCCV Operation

SUMMARY STEPS

    1.    enable

    2.    configure terminal

    3.    ip sla operation-number

    4.    mpls lsp ping pseudowire peer-ipaddr vc-id [source-ipaddr source-ipaddr]

    5.    exp exp-bits

    6.    frequency seconds

    7.    request-data-size bytes

    8.    secondary-frequency {both | connection-loss | timeout} frequency

    9.    tag text

    10.    threshold milliseconds

    11.    timeout milliseconds

    12.    exit

    13.    ip sla reaction-configuration operation-number [react monitored-element] [threshold-type {never | immediate | consecutive [consecutive-occurrences] | xofy [x-value y-value] | average [number-of-probes]}] [threshold-value upper-threshold lower-threshold] [action-type {none | trapOnly | triggerOnly | trapAndTrigger}]

    14.    ip sla logging traps

    15.    ip sla schedule operation-number [life {forever | seconds}] [start-time {hh : mm[: ss] [month day | day month] | pending | now | after hh : mm : ss}] [ageout seconds] [recurring]

    16.    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 ip sla operation-number


    Example:
    Router(config)# ip sla 777 
     

    Begins configuring an IP SLAs operation and enters IP SLA configuration mode.

     
    Step 4 mpls lsp ping pseudowire peer-ipaddr vc-id [source-ipaddr source-ipaddr]


    Example:
    Router(config-ip-sla)# mpls lsp ping 
    pseudowire 192.168.1.103 123 source-ipaddr 192.168.1.102
     

    Configures the IP SLAs operation as an LSP pseudo-wire ping and enters VCCV configuration mode.

     
    Step 5 exp exp-bits


    Example:
    
    
            


    Example:
    Router(config-sla-vccv)# exp 5
     

    (Optional) Specifies the experimental field value in the header for an echo request packet of an IP SLAs operation.

     
    Step 6 frequency seconds


    Example:
    Router(config-sla-vccv)# frequency 120 
     

    (Optional) Specifies the rate at which a specified IP SLAs operation repeats.

     
    Step 7 request-data-size bytes


    Example:
    Router(config-sla-vccv)# request-data-size 200
     

    (Optional) Specifies the protocol data size for a request packet of an IP SLAs operation.

     
    Step 8 secondary-frequency {both | connection-loss | timeout} frequency


    Example:
    Router(config-sla-vccv)# secondary-frequency connection-loss 10
     

    (Optional) Sets the faster measurement frequency (secondary frequency) to which an IP SLAs operation should change when a reaction condition occurs.

     
    Step 9 tag text


    Example:
    Router(config-sla-vccv)# tag testgroup
     

    (Optional) Creates a user-specified identifier for an IP SLAs operation.

     
    Step 10 threshold milliseconds


    Example:
    
    
            


    Example:
    Router(config-sla-vccv)# threshold 6000
     

    (Optional) Sets the upper threshold value for calculating network monitoring statistics created by an IP SLAs operation.

     
    Step 11 timeout milliseconds


    Example:
    Router(config-sla-vccv)# timeout 7000
     

    (Optional) Specifies the amount of time the IP SLAs operation waits for a response from its request packet.

     
    Step 12 exit


    Example:
    Router(config-sla-vccv)# exit
     

    Exits VCCV configuration mode and returns to global configuration mode.

     
    Step 13 ip sla reaction-configuration operation-number [react monitored-element] [threshold-type {never | immediate | consecutive [consecutive-occurrences] | xofy [x-value y-value] | average [number-of-probes]}] [threshold-value upper-threshold lower-threshold] [action-type {none | trapOnly | triggerOnly | trapAndTrigger}]


    Example:
    Router(config)# ip sla reaction-configuration 777 react connectionLoss threshold-type consecutive 3 action-type traponly
     

    (Optional) Configures certain actions to occur based on events under the control of Cisco IOS IP SLAs.

     
    Step 14 ip sla logging traps


    Example:
    Router(config)# ip sla logging traps
     

    (Optional) Enables the generation of SNMP system logging messages specific to IP SLAs trap notifications.

     
    Step 15 ip sla schedule operation-number [life {forever | seconds}] [start-time {hh : mm[: ss] [month day | day month] | pending | now | after hh : mm : ss}] [ageout seconds] [recurring]


    Example:
    Router(config)# ip sla schedule 777 life forever start-time now
     

    Configures the scheduling parameters for an IP SLAs operation.

     
    Step 16 exit


    Example:
    Router(config)# exit
     

    Exits global configuration submode and returns to privileged EXEC mode.

     

    Troubleshooting Tips

    Use the debug ip sla trace and debug ip sla error commands to help troubleshoot issues with an individual IP SLAs PWE3 service via VCCV operation.

    What to Do Next

    To display the results of an individual IP SLAs operation use the show ip sla statistics and show ip sla statistics aggregated commands. Checking the output for fields that correspond to criteria in your service level agreement will help you determine whether the service metrics are acceptable.

    Configuration Examples for IP SLAs for MPLS Pseudo Wire via VCCM

    Example Manually Configuring an IP SLAs VCCV Operation

    The following example shows how to manually configure an IP SLAs VCCV operation in conjunction with the proactive threshold monitoring and multioperation scheduling capabilities of the LSP Health Monitor.

    In this example, a VC with the identifier 123 has already been established between the PE device and its peer at IP address 192.168.1.103.

    IP SLAs VCCV operation 777 is configured with operation parameters and reaction conditions, and it is scheduled to begin immediately and run indefinitely.

    ip sla 777
     mpls lsp ping pseudowire 192.168.1.103 123 
      exp 5
      frequency 120
      secondary-frequency timeout 30
      tag testgroup
      threshold 6000
      timeout 7000
      exit
    !
     ip sla reaction-configuration 777 react rtt threshold-value 6000 3000 threshold-type immediate 3 action-type traponly 
     ip sla reaction-configuration 777 react connectionLoss threshold-type immediate action-type traponly
     ip sla reaction-configuration 777 react timeout threshold-type consecutive 3 action-type traponly
     ip sla logging traps
    !
     ip sla schedule 777 life forever start-time now
     exit

    RTT Thresholds

    The threshold command configures 6000 milliseconds as the amount of time for a rising threshold to be declared on the monitored pseudo-wire. The first ip sla reaction-configuration command specifies that an SNMP logging trap is to be sent immediately if the round-trip time violates the upper threshold of 6000 milliseconds or the lower threshold of 3000 milliseconds.

    Connection Loss

    The second ip sla reaction-configuration command specifies that an SNMP logging trap is to be sent immediately if a connection loss occurs for the monitored pseudo-wire.

    Response Timeout

    The timeout command configures 7000 seconds as the amount of time that VCCV operation 777 waits for a response from its request packet before a timeout is declared. The secondary-frequency command specifies that, if a timeout occurs, the measurement frequency of the operation repeats is to be increased from 120 seconds (the initial measurement frequency specified using the frequency command) to a faster rate of 30 seconds. The third ip sla reaction-configuration command specifies that an SNMP logging trap is to be sent if three consecutive timeouts occur.

    Additional References

    Related Documents

    Related Topic

    Document Title

    MPLS LSP discovery management tool

    "MPLS EM-MPLS LSP Multipath Tree Trace" chapter of the Multiprotocol Label Switching Configuration Guide

    Configuring standard IP access lists

    "Access Control Lists" chapter of the Security Configuration Guide: Securing the Data Plane guide

    Multioperation scheduling for IP SLAs

    "Configuring Multioperation Scheduling of IP SLAs Operations" chapter of the Cisco IOS P SLAs Configuration Guide

    Proactive threshold monitoring for IP SLAs

    " Configuring Proactive Threshold Monitoring of IP SLAs Operations" chapter of the Cisco IOS IP SLAs Configuration Guide

    Cisco IOS commands

    Cisco IOS Master Commands List, All Releases

    Cisco IOS IP SLAs commands

    Cisco IOS IP SLAs Command Reference

    Standards

    Standard

    Title

    draft-ietf-mpls-lsp-ping-09.txt

    Detecting MPLS Data Plane Failures

    draft-ietf-mpls-oam-frmwk-03.txt

    A Framework for MPLS Operations and Management (OAM)

    draft-ietf-mpls-oam-requirements-06.txt

    OAM Requirements for MPLS Networks

    MIBs

    MIB

    MIBs Link

    CISCO-RTTMON-MIB

    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

    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

    Related Information

    Feature Information for IP SLAs for MPLS PWE3 via VCCM

    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 IP SLAs for MPLS PWE3 via VCCM

    Feature Name

    Releases

    Feature Information

    IP SLAs for MPLS Pseudo Wire (PWE3) via VCCM

    12(33)SB

    12.2(33)SRC

    15.0(1)S

    Cisco IOS XE 3.1.0SG

    The IP SLAs VCCV operation was added to support Virtual Circuit Connectivity Verification (VCCV) for Pseudo-Wire Emulation Edge-to-Edge (PWE3) services across MPLS networks.