Restrictions for IP SLAs for MPLS Pseudo Wire via VCCV
LSP discovery is not supported for IP SLAs VCCV operations.
The documentation set for this product strives to use bias-free language. For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. Exceptions may be present in the documentation due to language that is hardcoded in the user interfaces of the product software, language used based on RFP documentation, or language that is used by a referenced third-party product. Learn more about how Cisco is using Inclusive Language.
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.
LSP discovery is not supported for IP SLAs VCCV operations.
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 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.
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.
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.
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.
Command or Action | Purpose | |
---|---|---|
Step 1 |
enable Example:
|
Enables privileged EXEC mode.
|
Step 2 |
configure terminal Example:
|
Enters global configuration mode. |
Step 3 |
ip sla operation-number Example:
|
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:
|
Configures the IP SLAs operation as an LSP pseudo-wire ping and enters VCCV configuration mode. |
Step 5 |
exp exp-bits Example:
Example:
|
(Optional) Specifies the experimental field value in the header for an echo request packet of an IP SLAs operation. |
Step 6 |
frequency seconds Example:
|
(Optional) Specifies the rate at which a specified IP SLAs operation repeats. |
Step 7 |
request-data-size bytes Example:
|
(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:
|
(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:
|
(Optional) Creates a user-specified identifier for an IP SLAs operation. |
Step 10 |
threshold milliseconds Example:
Example:
|
(Optional) Sets the upper threshold value for calculating network monitoring statistics created by an IP SLAs operation. |
Step 11 |
timeout milliseconds Example:
|
(Optional) Specifies the amount of time the IP SLAs operation waits for a response from its request packet. |
Step 12 |
exit Example:
|
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:
|
(Optional) Configures certain actions to occur based on events under the control of Cisco IOS IP SLAs. |
Step 14 |
ip sla logging traps Example:
|
(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:
|
Configures the scheduling parameters for an IP SLAs operation. |
Step 16 |
exit Example:
|
Exits global configuration submode and returns to privileged EXEC mode. |
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.
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.
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
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.
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.
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.
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 IP SLAs commands |
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 |
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: |
RFC |
Title |
---|---|
No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature. |
-- |
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. |
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.
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. |