Table Of Contents
IP SLAs—Analyzing IP Service Levels Using the UDP Echo Operation
Prerequisites for the IP SLAs UDP Echo Operation
Restrictions for the IP SLAs UDP Echo Operation
Information About the IP SLAs UDP Echo Operation
How to Configure the IP SLAs UDP Echo Operation
Configuring the IP SLAs Responder on the Destination Device
Configuring and Scheduling a UDP Echo Operation on the Source Device
Configuring and Scheduling a Basic UDP Echo Operation on the Source Device
Configuring and Scheduling a UDP Echo Operation with Optional Parameters on the Source Device
Configuration Examples for the IP SLAs UDP Echo Operation
Configuring a UDP Echo Operation: Example
Feature Information for the IP SLAs UDP Echo Operation
IP SLAs—Analyzing IP Service Levels Using the UDP Echo Operation
First Published: August 14, 2006Last Updated: July 16, 2008This module describes how to use the Cisco IOS IP Service Level Agreements (SLAs) User Datagram Protocol (UDP) Echo operation to monitor end-to-end response time between a Cisco router and devices using IPv4 or IPv6. IP SLAs is a portfolio of technology embedded in most devices that run Cisco IOS software, which allows Cisco customers to analyze IP service levels for IP applications and services, to increase productivity, to lower operational costs, and to reduce the frequency of network outages. IP SLAs uses active traffic monitoring—the generation of traffic in a continuous, reliable, and predictable manner—for measuring network performance. UDP echo accuracy is enhanced by using the IP SLAs Responder at the destination Cisco router. This module also demonstrates how the results of the UDP echo operation can be displayed and analyzed to determine how a UDP application is performing.
Finding Feature Information
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 for the IP SLAs UDP Echo Operation" section.
Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
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Prerequisites for the IP SLAs UDP Echo Operation
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Restrictions for the IP SLAs UDP Echo Operation
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Information About the IP SLAs UDP Echo Operation
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How to Configure the IP SLAs UDP Echo Operation
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Configuration Examples for the IP SLAs UDP Echo Operation
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Feature Information for the IP SLAs UDP Echo Operation
Prerequisites for the IP SLAs UDP Echo Operation
Before configuring the IP SLAs UDP echo operation you should be familiar with the "Cisco IOS IP SLAs Overview" chapter of the Cisco IOS IP SLAs Configuration Guide.
Restrictions for the IP SLAs UDP Echo Operation
We recommend using a Cisco networking device as the destination device, although any networking device that supports RFC 862, Echo Protocol, can be used.
Information About the IP SLAs UDP Echo Operation
To perform the tasks required to monitor UDP performance using IP SLA, you should understand the following concept:
UDP Echo Operation
The UDP echo operation measures end-to-end response time between a Cisco router and devices using IP. UDP is a network layer (Layer 3) Internet protocol that is used for many IP services. UDP echo is used to measure response times and test end-to-end connectivity.
In Figure 1 Router A has been configured as an IP SLAs Responder and Router B is configured as the source IP SLAs device.
Figure 1 UDP Echo Operation
Response time (round-trip time) is computed by measuring the time taken between sending a UDP echo request message from Router B to the destination router—Router A—and receiving a UDP echo reply from Router A. UDP echo accuracy is enhanced by using the IP SLAs Responder at Router A, the destination Cisco router. If the destination router is a Cisco router, then IP SLAs sends a UDP datagram to any port number that you specified. Using the IP SLAs Responder is optional for a UDP echo operation when using Cisco devices. The IP SLAs Responder cannot be configured on non-Cisco devices.
The results of a UDP echo operation can be useful in troubleshooting issues with business-critical applications by determining the round-trip delay times and testing connectivity to both Cisco and non-Cisco devices.
How to Configure the IP SLAs UDP Echo Operation
This section contains the following procedures:
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Configuring the IP SLAs Responder on the Destination Device
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Configuring and Scheduling a UDP Echo Operation on the Source Device (required)
Configuring the IP SLAs Responder on the Destination Device
Perform this task to enable the IP SLAs Responder on the destination Cisco device of a UDP echo operation. A UDP echo operation measures round-trip delay times and tests connectivity to Cisco and non-Cisco devices.
Prerequisites
If you are using the IP SLAs Responder, ensure that the networking device to be used as the responder is a Cisco device and that you have connectivity to that device through the network.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
ip sla responder
4.
exit
DETAILED STEPS
Configuring and Scheduling a UDP Echo Operation on the Source Device
To monitor UDP performance on a device, use the IP SLAs UDP echo operation. A UDP echo operation measures round-trip delay times and tests connectivity to Cisco and non-Cisco devices.
Perform one of the following tasks in this section, depending on whether you want to configure a basic UDP echo operation or configure a UDP echo operation with optional parameters:
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Configuring and Scheduling a Basic UDP Echo Operation on the Source Device
•
Configuring and Scheduling a UDP Echo Operation with Optional Parameters on the Source Device
Prerequisites
If you are using the IP SLAs Responder, ensure that you have completed the "Configuring the IP SLAs Responder on the Destination Device" section before you start this task.
Configuring and Scheduling a Basic UDP Echo Operation on the Source Device
Perform this task to enable a UDP echo operation without any optional parameters.
For information on scheduling a group of operations, see the "IP SLAs—Multioperation Scheduling of IP SLAs Operations" chapter of the Cisco IOS IP SLAs Configuration Guide.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
ip sla operation-number
4.
udp-echo {destination-ip-address | destination-hostname} destination-port [source-ip {ip-address | hostname} source-port port-number] [control {enable | disable}]
5.
frequency seconds
6.
exit
7.
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]
8.
exit
9.
show ip sla configuration [operation-number]
DETAILED STEPS
Examples
The following example shows the configuration of an IP SLAs operation type of UDP echo that will start immediately and run indefinitely.
ip sla 5udp-echo 172.29.139.134 5000frequency 30!ip sla schedule 5 start-time now life forever.Troubleshooting Tips
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If the IP SLAs operation is not running and generating statistics, add the verify-data command to the configuration of the operation (while configuring in IP SLA configuration mode) to enable data verification. When enabled, each operation response is checked for corruption. Use the verify-data command with caution during normal operations because it generates unnecessary overhead.
•
Use the debug ip sla trace and debug ip sla error commands to help troubleshoot issues with an IP SLAs operation.
What to Do Next
To view and interpret the results of an IP SLAs operation use the show ip sla statistics command. Checking the output for fields that correspond to criteria in your service level agreement will help you determine whether the service metrics are acceptable.
Configuring and Scheduling a UDP Echo Operation with Optional Parameters on the Source Device
Perform this task to enable a UDP echo operation on the source device and configure some optional IP SLAs parameters. The source device is the location at which the measurement statistics are stored.
Note
The tos command defines the type of service (ToS) byte in the IPv4 header of an IP SLAs operation and is valid only in IPv4 networks. The traffic-class command defines the traffic class byte in the IPv6 header for a supported IP SLAs operation.
The flow-label command defines the value in the flow label field in the IPv6 header for a supported IP SLAs operation and is valid only in IPv6 networks.For information on scheduling a group of operations, see the "IP SLAs—Multioperation Scheduling of IP SLAs Operations" chapter of the Cisco IOS IP SLAs Configuration Guide.
SUMMARY STEPS
1.
enable
2.
configure terminal
3.
ip sla operation-number
4.
udp-echo {destination-ip-address | destination-hostname} destination-port [source-ip {ip-address | hostname} source-port port-number] [control {enable | disable}]
5.
history buckets-kept size
6.
data-pattern hex-pattern
7.
history distributions-of-statistics-kept size
8.
history enhanced [interval seconds] [buckets number-of-buckets]
9.
history filter {none | all | overThreshold | failures}
10.
frequency seconds
11.
history hours-of-statistics-kept hours
12.
history lives-kept lives
13.
owner owner-id
14.
request-data-size bytes
15.
history statistics-distribution-interval milliseconds
16.
tag text
17.
threshold milliseconds
18.
timeout milliseconds
19.
tos number
or
traffic-class number20.
flow-label number
21.
verify-data
22.
exit
23.
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]
24.
exit
25.
show ip sla configuration [operation-number]
DETAILED STEPS
Examples
The following sample output shows the configuration of all the IP SLAs parameters (including defaults) for the UDP echo operation number 5.
Router# show ip sla configuration 5Complete configuration Table (includes defaults)Entry number: 5Owner: jdoeTag: FLL-ROType of operation to perform: udpEchoTarget address: 172.29.139.134Source address: 0.0.0.0Target port: 5000Source port: 0Request size (ARR data portion): 160Operation timeout (milliseconds): 1000Type Of Service parameters: 128Verify data: NoData pattern:Vrf Name:Control Packets: enabledOperation frequency (seconds): 30Next Scheduled Start Time: Start Time already passedGroup Scheduled: FALSELife (seconds): ForeverEntry Ageout (seconds): neverRecurring (Starting Everyday): FALSEStatus of entry (SNMP RowStatus): ActiveThreshold (milliseconds): 5000Number of statistic hours kept: 2Number of statistic distribution buckets kept: 1Statistic distribution interval (milliseconds): 20Enhanced History:Aggregation Interval:60 Buckets:2Number of history Lives kept: 0Number of history Buckets kept: 15History Filter Type: NoneTroubleshooting Tips
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If the IP SLAs operation is not running and generating statistics, add the verify-data command to the configuration of the operation (while configuring in IP SLA configuration mode) to enable data verification. When enabled, each operation response is checked for corruption. Use the verify-data command with caution during normal operations because it generates unnecessary overhead.
•
Use the debug ip sla trace and debug ip sla error commands to help troubleshoot issues with an IP SLAs operation.
What to Do Next
To view and interpret the results of an IP SLAs operation use the show ip sla statistics command. 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 the IP SLAs UDP Echo Operation
This section contains the following example:
•
Configuring a UDP Echo Operation: Example
Configuring a UDP Echo Operation: Example
The following example configures an IP SLAs operation type of UDP echo that will start immediately and run indefinitely.
ip sla 5udp-echo 172.29.139.134 5000frequency 30request-data-size 160tos 128timeout 1000tag FLL-ROip sla schedule 5 life forever start-time nowWhere to Go Next
For information about other types of IP SLAs operations and IP SLAs features, see the Cisco IOS IP SLAs Features Roadmap.
Additional References
The following sections provide references related to monitoring UDP echo operations using IP SLA.
Related Documents
Related Topic Document TitleCisco IOS IP SLAs command-line interface enhancements
Cisco IOS IP Service Level Agreements Command Line Interface, Cisco white paper
Cisco IOS IP SLAs commands
Standards
Standards TitleNo new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.
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MIBs
MIBs MIBs LinkCISCO-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:
RFCs
Technical Assistance
Feature Information for the IP SLAs UDP Echo Operation
Table 1 lists the release history for this feature.
Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note
Table 1 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.
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