Configuring IP SLAs ICMP Path Echo Operations

This module describes how to configure an IP Service Level Agreements (SLAs) Internet Control Message Protocol (ICMP) Path Echo operation to monitor end-to-end and hop-by-hop response time between a Cisco device and other devices using IP. ICMP Path Echo is useful for determining network availability and for troubleshooting network connectivity issues. The results of the ICMP Path Echo operation can be displayed and analyzed to determine how ICMP is performing.

Restrictions for IP SLAs ICMP Path Echo Operations

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 IP SLAs ICMP Path Echo Operations

ICMP Path Echo Operation

To monitor ICMP Path Echo performance on a device, use the IP SLAs ICMP Path Echo operation. An ICMP Path Echo operation measures end-to-end and hop-by-hop response time between a Cisco device and other devices using IP. ICMP Path Echo is useful for determining network availability and for troubleshooting network connectivity issues.

The IP SLAs ICMP Path Echo operation records statistics for each hop along the path that the IP SLAs operation takes to reach its destination. The ICMP Path Echo operation determines this hop-by-hop response time between a Cisco device and any IP device on the network by discovering the path using the traceroute facility.

In the figure below the source IP SLAs device uses traceroute to discover the path to the destination IP device. A ping is then used to measure the response time between the source IP SLAs device and each subsequent hop in the path to the destination IP device.

Figure 1. ICMP Path Echo Operation

Using the statistics recorded for the response times and availability, the ICMP Path Echo operation can identify a hop in the path that is causing a bottleneck.

How to Configure IP SLAs ICMP Path Echo Operations

Configuring an ICMP Path Echo Operation on the Source Device


Note

This operation does not require an IP SLAs Responder on the destination device.

Perform only one of the following tasks:

Configuring a Basic ICMP Path Echo Operation on the Source Device

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. ip sla operation-id
  4. path-echo {destination-ip-address | destination-hostname } [source-ip {ip-address | hostname }]
  5. frequency seconds
  6. end

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

ip sla operation-id

Example:

Device(config)# ip sla 7

Specifies an ID number for the operation being configured, and enters IP SLA configuration mode.

Step 4

path-echo {destination-ip-address | destination-hostname } [source-ip {ip-address | hostname }]

Example:

Device(config-ip-sla)# path-echo 172.29.139.134

Defines a Path Echo operation and enters IP SLA Path Echo configuration mode.

Step 5

frequency seconds

Example:

Device(config-ip-sla-pathEcho)# frequency 30

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

Step 6

end

Example:

Device(config-ip-sla-pathEcho)# end

Exits to privileged EXEC mode.

Example

The following example shows the configuration of the IP SLAs ICMP Path Echo operation number 7 that will start in 30 seconds and run for 5 minutes. 


ip sla 7
 path-echo 172.29.139.134
 frequency 30
!
ip sla schedule 7 start-time after 00:00:30 life 300

Configuring an ICMP Path Echo Operation with Optional Parameters on the Source Device

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. ip sla operation-number
  4. path-echo {destination-ip-address | destination-hostname } [source-ip {ip-address | hostname }]
  5. history buckets-kept size
  6. history distributions-of-statistics-kept size
  7. history filter {none | all | overThreshold | failures }
  8. frequency seconds
  9. history hours-of-statistics-kept hours
  10. history lives-kept lives
  11. owner owner-id
  12. paths-of-statistics-kept size
  13. request-data-size bytes
  14. samples-of-history-kept samples
  15. history statistics-distribution-interval milliseconds
  16. tag text
  17. threshold milliseconds
  18. timeout milliseconds
  19. tos number
  20. verify-data
  21. vrf vrf-name
  22. end

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:

Device> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

ip sla operation-number

Example:

Device(config)# ip sla 10

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

Step 4

path-echo {destination-ip-address | destination-hostname } [source-ip {ip-address | hostname }]

Example:

Device(config-ip-sla)# path-echo 172.29.139.134

Defines a Path Echo operation and enters IP SLA Path Echo configuration mode.

Step 5

history buckets-kept size

Example:

Device(config-ip-sla-pathEcho)# history buckets-kept 25

(Optional) Sets the number of history buckets that are kept during the lifetime of an IP SLAs operation.

Step 6

history distributions-of-statistics-kept size

Example:

Device(config-ip-sla-pathEcho)# history distributions-of-statistics-kept 5

(Optional) Sets the number of statistics distributions kept per hop during an IP SLAs operation.

Step 7

history filter {none | all | overThreshold | failures }

Example:

Device(config-ip-sla-pathEcho)# history filter failures

(Optional) Defines the type of information kept in the history table for an IP SLAs operation.

Step 8

frequency seconds

Example:

Device(config-ip-sla-pathEcho)# frequency 30

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

Step 9

history hours-of-statistics-kept hours

Example:

Device(config-ip-sla-pathEcho)# history hours-of-statistics-kept 4

(Optional) Sets the number of hours for which statistics are maintained for an IP SLAs operation.

Step 10

history lives-kept lives

Example:

Device(config-ip-sla-pathEcho)# history lives-kept 5

(Optional) Sets the number of lives maintained in the history table for an IP SLAs operation.

Step 11

owner owner-id

Example:

Device(config-ip-sla-pathEcho)# owner admin

(Optional) Configures the Simple Network Management Protocol (SNMP) owner of an IP SLAs operation.

Step 12

paths-of-statistics-kept size

Example:

Device(config-ip-sla-pathEcho)# paths-of-statistics-kept 3

(Optional) Sets the number of paths for which statistics are maintained per hour for an IP SLAs operation.

Step 13

request-data-size bytes

Example:

Device(config-ip-sla-pathEcho)# request-data-size 64

(Optional) Sets the protocol data size in the payload of an IP SLAs operation's request packet.

Step 14

samples-of-history-kept samples

Example:

Device(config-ip-sla-pathEcho)# samples-of-history-kept 10

(Optional) Sets the number of entries kept in the history table per bucket for an IP SLAs operation.

Step 15

history statistics-distribution-interval milliseconds

Example:

Device(config-ip-sla-pathEcho)# history statistics-distribution-interval 10

(Optional) Sets the time interval for each statistics distribution kept for an IP SLAs operation.

Step 16

tag text

Example:

Device(config-ip-sla-pathEcho)# tag TelnetPollServer1

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

Step 17

threshold milliseconds

Example:

Device(config-ip-sla-pathEcho)# threshold 10000

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

Step 18

timeout milliseconds

Example:

Device(config-ip-sla-pathEcho)# timeout 10000

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

Step 19

tos number

Example:

Device(config-ip-sla-pathEcho)# tos 160

(Optional) Defines a type of service (ToS) byte in the IP header of an IP SLAs operation.

Step 20

verify-data

Example:

Device(config-ip-sla-pathEcho)# verify-data

(Optional) Causes an IP SLAs operation to check each reply packet for data corruption.

Step 21

vrf vrf-name

Example:

Device(config-ip-sla-pathEcho)# vrf vpn-A

(Optional) Allows monitoring within Multiprotocol Label Switching (MPLS) Virtual Private Networks (VPNs) using IP SLAs operations.

Step 22

end

Example:

Device(config-ip-sla-pathEcho)# end

Exits to privileged EXEC mode.

Scheduling IP SLAs Operations

Before you begin

  • All IP Service Level Agreements (SLAs) operations to be scheduled must be already configured.
  • The frequency of all operations scheduled in a multioperation group must be the same.
  • The list of one or more operation ID numbers to be added to a multioperation group must be limited to a maximum of 125 characters in length, including commas (,).

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. Enter one of the following commands:
    • 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 ]
    • ip sla group schedule group-operation-number operation-id-numbers {schedule-period schedule-period-range | schedule-together } [ageout seconds ] frequency group-operation-frequency [life {forever | seconds }] [start-time {hh:mm [:ss ] [month day | day month ] | pending | now | after hh:mm [:ss] }]
  4. end
  5. show ip sla group schedule
  6. show ip sla configuration

DETAILED STEPS

  Command or Action Purpose

Step 1

enable

Example:


Device> enable

Enables privileged EXEC mode.

  • Enter your password if prompted.

Step 2

configure terminal

Example:


Device# configure terminal

Enters global configuration mode.

Step 3

Enter one of the following commands:

  • 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 ]
  • ip sla group schedule group-operation-number operation-id-numbers {schedule-period schedule-period-range | schedule-together } [ageout seconds ] frequency group-operation-frequency [life {forever | seconds }] [start-time {hh:mm [:ss ] [month day | day month ] | pending | now | after hh:mm [:ss] }]

Example:


Device(config)# ip sla schedule 10 life forever start-time now

Device(config)# ip sla group schedule 10 schedule-period frequency

Device(config)# ip sla group schedule 1 3,4,6-9 life forever start-time now 

Device(config)# ip sla schedule 1 3,4,6-9 schedule-period 50 frequency range 80-100

  • Configures the scheduling parameters for an individual IP SLAs operation.

  • Specifies an IP SLAs operation group number and the range of operation numbers for a multioperation scheduler.

Step 4

end

Example:


Device(config)# end

Exits global configuration mode and returns to privileged EXEC mode.

Step 5

show ip sla group schedule

Example:


Device# show ip sla group schedule

(Optional) Displays IP SLAs group schedule details.

Step 6

show ip sla configuration

Example:


Device# show ip sla configuration

(Optional) Displays IP SLAs configuration details.

Troubleshooting Tips

  • If the IP Service Level Agreements (SLAs) operation is not running and not generating statistics, add the verify-data command to the configuration (while configuring in IP SLA configuration mode) to enable data verification. When data verification is 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 add proactive threshold conditions and reactive triggering for generating traps (or for starting another operation) to an IP Service Level Agreements (SLAs) operation, see the “Configuring Proactive Threshold Monitoring” section.

Configuration Examples for IP SLAs ICMP Path Echo Operations

Example Configuring an ICMP Path Echo Operation

The following example shows how to configure an IP SLAs operation type of ICMP Path Echo that will start after 30 seconds and run for 5 minutes. The figure below depicts the ICMP Path Echo operation.

Figure 2. ICMP Path Echo Operation

This example sets a Path Echo operation (ip sla 3) from Device B to Device A using IP/ICMP. The operation attempts to execute three times in 25 seconds (first attempt at 0 seconds).

Device B Configuration


ip sla 3
 path-echo 172.29.139.134
 frequency 10
 tag SGN-RO
 timeout 1000
ip sla schedule 3 life 25

Additional References for IP SLAs ICMP Echo Operations

Related Documents

Related Topic

Document Title

Cisco IOS commands

Cisco IOS Master Commands List, All Releases

IP SLAs commands

Cisco IOS IP SLAs Command Reference

Information about Cisco IP SLAs

“Cisco IOS IP SLAs Overview” module of the IP SLAs Configuration Guide

Standards and RFCs

Standard/RFC

Title

RFC 862

Echo Protocol

MIBs

MIBs

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

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

Feature Information for IP SLAs ICMP Path Echo Operations

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 1. Feature Information for IP SLAs ICMP Path Echo Operations

Feature Name

Releases

Feature Information

IP SLAs ICMP Path Echo Operation

12.2(31)SB2

12.2(33)SRB1

12.2(33)SXH

12.3(14)T

Cisco IOS XE Release 2.1

15.0(1)S

Cisco IOS XE 3.1.0SG

The Cisco IOS IP SLAs Internet Control Message Protocol (ICMP) path echo operation allows you to measure end-to-end and hop-by-hop network response time between a Cisco device and other devices using IP.

IP SLA 4.0 - IP v6 phase2

15.2(3)T

Cisco IOS XE Release 3.7S

15.1(2)SG

Cisco IOS XE Release 3.4SG

Support was added for operability in IPv6 networks.

The following commands are introduced or modified: path-echo (IP SLA), show ip sla configuration , show ip sla summary .