Configuring IP SLAs ICMP Echo Operations

This module describes how to configure an IP Service Level Agreements (SLAs) Internet Control Message Protocol (ICMP) Echo operation to monitor end-to-end response time between two devices using IPv4 . ICMP Echo is useful for troubleshooting network connectivity issues. This module also demonstrates how the results of the ICMP Echo operation can be displayed and analyzed to determine how the network IP connections are performing.

This chapter includes the following sections:

ICMP Echo Operation

The Internet Control Message Protocol (ICMP) Echo operation measures the end-to-end response time between two devices that use IP. The response time is computed by measuring the time taken between sending an ICMP Echo request message to the destination and receiving an ICMP Echo reply. An ICMP Echo is useful for troubleshooting network connectivity issues. The results of the ICMP Echo operation can be displayed and analyzed to determine how the network IP connections are performing.

In the following figure, the ICMP Echo operation uses the ping test to measure the response time between the source IP SLAs device and the destination IP device. Many customers use IP SLAs ICMP-based operations, in-house ping testing, or ping-based dedicated probes for response time measurements.

Figure 1. ICMP Echo Operation



The IP SLAs ICMP Echo operation conforms to the same IETF specifications for ICMP ping testing and the two methods result in the same response times.

Guidelines and Limitations for IP SLAs ICMP Echo Operations

We recommend that you use a Cisco networking device as the destination device although you can use any networking device that supports RFC 862, the Echo protocol.

Configuring an ICMP Echo Operation


Note

You do not need to configure an IP SLAs Responder on the destination device.

Perform one of the following tasks:

  • Configuring a basic ICMP Echo operation on the source device

  • Configuring an ICMP Echo operation with optional parameters

Configuring a Basic ICMP Echo Operation on a Source Device

Procedure
 Command or ActionPurpose
Step 1 configure terminal


Example: 
switch# configure terminal
 

Enters global configuration mode.

 
Step 2 feature sla sender


Example: 
switch(config)# feature sla sender
 

Enables the IP SLAs operation feature.

 
Step 3ip sla operation-number


Example: 
switch(config)# ip sla 6
 

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

 
Step 4icmp-echo {destination-ipv4-address | destination-ipv6-address | destination-hostname} [source-ip {ipv4-address | ipv6-address | hostname} | source-interface interface-name]


Example: 
switch(config-ip-sla)# icmp-echo 192.0.2.134


Example: 
switch(config-ip-sla)# icmp-echo 2016:1:1:1::2
 

Defines an ICMP Echo operation and enters IP SLA ICMP Echo configuration mode.

Note   

IPv6 is available only from Cisco NX-OS Release 8.0 onwards.

 
Step 5end


Example: 
switch(config-ip-sla-echo)# end
 

Exits IP SLA ICMP Echo configuration mode and returns to privileged EXEC mode.

 

Configuring an ICMP Echo Operation with Optional Parameters

Before You Begin

Perform this task on the source device.

Procedure
 Command or ActionPurpose
Step 1configure terminal


Example: 
switch# configure terminal
 

Enters global configuration mode.

 
Step 2feature sla sender


Example: 
switch(config)# feature sla sender
 

Enables the IP SLAs operation feature.

 
Step 3ip sla operation-number


Example: 
switch(config)# ip sla 6
 

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

 
Step 4icmp-echo {destination-ipv4-address | destination-ipv6-address | destination-hostname} [source-ip {ipv4-address | ipv6-address | hostname} | source-interface interface-name]


Example: 
switch(config-ip-sla)# icmp-echo 192.0.2.134 source-ip 192.0.2.132


Example: 
switch(config-ip-sla)# icmp-echo 2016:1:1:1::2 source-ip 2016:1:1:1::2
 

Defines an Echo operation and enters IP SLA Echo configuration mode.

Note   

IPv6 is available only from Cisco NX-OS Release 8.0 onwards.

 
Step 5history buckets-kept size


Example: 
switch(config-ip-sla-echo)# history buckets-kept 25
  		(Optional)

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

 
Step 6history distributions-of-statistics-kept size


Example: 
switch(config-ip-sla-echo)# history distributions-of-statistics-kept 5
  		(Optional)

Sets the number of statistics distributions that are kept per hop during an IP SLAs operation.

 
Step 7history enhanced [interval seconds] [buckets number-of-buckets


Example: 
switch(config-ip-sla-echo)# history enhanced interval 900 buckets 100
  		(Optional)

Enables enhanced history gathering for an IP SLAs operation.

 
Step 8history filter {none | all | overThreshold | failures}


Example: 
switch(config-ip-sla-echo)# history filter failures
  		(Optional)

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

 
Step 9frequency seconds


Example: 
switch(config-ip-sla-echo)# frequency 30
  		(Optional)

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

 
Step 10history hours-of-statistics-kept hours


Example: 
switch(config-ip-sla-echo)# history hours-of-statistics-kept 4
  		(Optional)

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

 
Step 11history lives-kept lives


Example: 
switch(config-ip-sla-echo)# history lives-kept 5
  		(Optional)

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

 
Step 12owner owner-id


Example: 
switch(config-ip-sla-echo)# owner admin
  		(Optional)

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

 
Step 13request-data-size bytes


Example: 
switch(config-ip-sla-echo)# request-data-size 64
  		(Optional)

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

 
Step 14history statistics-distribution-interval milliseconds


Example: 
switch(config-ip-sla-echo)# history statistics-distribution-interval 10
  		(Optional)

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

 
Step 15tag text


Example: 
switch(config-ip-sla-echo)# tag TelnetPollServer1
  		(Optional)

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

 
Step 16threshold milliseconds


Example: 
switch(config-ip-sla-echo)# threshold 10000
  		(Optional)

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

 
Step 17timeout milliseconds


Example: 
switch(config-ip-sla-echo)# timeout 10000
  		(Optional)

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

 
Step 18Depending on the IP version you are using, use one of the following commands:
  • tos number
  • traffic-class number


Example: 
switch(config-ip-sla-echo)# tos 160


Example: 
switch(config-ip-sla-echo)# traffic-class 160
  		(Optional)

In an IPv4 network, defines the ToS byte in the IPv4 header of an IP SLA operation.

or

In an IPv6 network, defines the traffic class byte in the IPv6 header for a supported IP SLA operation.

Note   

IPv6 is available only from Cisco NX-OS Release 8.0 onwards.

 
Step 19verify-data


Example: 
switch(config-ip-sla-echo)# verify-data
  		(Optional)

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

 
Step 20vrf {vrf-name | default | management}


Example: 
switch(config-ip-sla-echo)# vrf vpn-A
  		(Optional)

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

 
Step 21end


Example: 
switch(config-ip-sla-echo)# end
 

Exits IP SLA Echo configuration mode and returns to privileged EXEC mode.

 

Scheduling IP SLAs Operations


Note

  • All IP SLAs operations that you want 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 is limited to a maximum of 125 characters in length, including commas (,).
Procedure
 Command or ActionPurpose
Step 1 configure terminal


Example: 
switch# configure terminal
 

Enters global configuration mode.

 
Step 2Perform one of the following tasks:
  • 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: 
switch(config)# ip sla schedule 10 life forever start-time now


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

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 3exit


Example: 
switch(config)# exit
 

Exits global configuration mode and returns to privileged EXEC mode.

 
Step 4show ip sla group schedule


Example: 
switch# show ip sla group schedule
 

Displays IP SLAs group schedule details.

 
Step 5show ip sla configuration


Example: 
switch# show ip sla configuration
 

Displays IP SLAs configuration details.

 

Troubleshooting Tips

  • If the IP SLAs operation is not running and not 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 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 to an IP Service Level Agreements (SLAs) operation for the purpose of generating traps or for starting another operation, see the “Configuring Proactive Threshold Monitoring” section in the “Configuring Proactive Threshold Monitoring for IP SLAs Operations” chapter.

Configuration Examples for IP SLA ICMP Echo Operations


Note

IPv6 is available only from Cisco NX-OS Release 8.0 onwards.

Example: Configuring a Basic ICMP Echo Operation on a Source Device

This example shows how to configure a basic ICMP Echo operation on a source device using IPv4:

switch# configure terminal
switch(config)# feature sla sender
switch(config)# ip sla 6
switch(config-ip-sla)# icmp-echo 192.0.2.134 source-ip 192.0.2.132
switch(config-ip-sla-echo)# end

This example shows how to configure a basic ICMP Echo Operation on a source device using IPv6:

switch# configure terminal
switch(config)# feature sla sender
switch(config)# ip sla 6
switch(config-ip-sla)# icmp-echo 2016:1:1:1::2 source-ip 2016:1:1:1::2
switch(config-ip-sla-echo)# end

Example: Configuring an ICMP Echo Operation with Optional Parameters

This example shows how to configure an IP SLAs operation type of ICMP Echo using IPv4 that will start immediately and run indefinitely:

switch# configure terminal
switch(config)# feature sla sender
switch(config)# ip sla 6
switch(config-ip-sla)# icmp-echo 192.0.2.134 source-ip 192.0.2.132
switch(config-ip-sla-echo)# frequency 300
switch(config-ip-sla-echo)# request-data-size 38
switch(config-ip-sla-echo)# tos 160
switch(config-ip-sla-echo)# timeout 6000
switch(config-ip-sla-echo)# tag SFO-RO
switch(config-ip-sla-echo)# end

This example shows how to configure an IP SLA operation type of ICMP Echo using IPv6 that will start immediately and run indefinitely:

switch# configure terminal
switch(config)# feature sla sender
switch(config)# ip sla 6
switch(config-ip-sla)# icmp-echo 2016:1:1:1::2 source-ip 2016:1:1:1::2
switch(config-ip-sla-echo)# frequency 300
switch(config-ip-sla-echo)# request-data-size 38
switch(config-ip-sla-echo)# traffic-class 160
switch(config-ip-sla-echo)# timeout 6000
switch(config-ip-sla-echo)# tag SFO-RO
switch(config-ip-sla-echo)# end

Example: Scheduling IP SLAs Operations

This example shows how to schedule an IP SLAs operation that is already configured:

switch# configure terminal
switch(config)# ip sla schedule 6 life forever start-time now
switch(config)# exit

Additional References for IP SLAs ICMP Echo Operations

Related Documents

Related Topic

Document Title

Cisco Nexus commands

Cisco Nexus 7000 Series Command Reference Master Index

Standards and RFCs

Standard/RFC Title

RFC 862

Echo Protocol

Technical Assistance

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Feature History for IP SLAs ICMP Echo Operations

Table 1 Feature History for IP SLAs ICMP Echo Operations

Feature Name

Releases

Feature Information

IP SLAs ICMP Echo Operation

6.2(2)

The Cisco IP SLAs ICMP echo operation allows you to measure the end-to-end network response time between two devices using IPv4.