ltm monitor icmp¶

ltm monitor icmp(1) BIG-IP TMSH Manual ltm monitor icmp(1)

NAME
icmp - Configures an Internet Control Message Protocol (ICMP) monitor.

MODULE
ltm monitor

SYNTAX
Configure the icmp component within the ltm monitor module using the syntax shown in the following sections.

CREATE/MODIFY
create icmp [name]
modify icmp [name]
options:
adaptive [enabled | disabled]
adaptive-divergence-type [relative | absolute]
adaptive-divergence-value [integer]
adaptive-limit [integer]
adaptive-sampling-timespan [integer]
app-service [[string] | none]
defaults-from [name]
description [string]
destination [ip address]
interval [integer]
manual-resume [enabled | disabled]
time-until-up [integer]
timeout [integer]
transparent [enabled | disabled]
up-interval [integer]

edit icmp [ [ [name] | [glob] | [regex] ] ... ]
options:
all-properties
non-default-properties

DELETE
delete icmp [name]

Note: You cannot delete default monitors.

RUN
run icmp [name] [destination [ip address]]

STOP
stop icmp [name]

DESCRIPTION
You can use the icmp component to configure a custom monitor, or you can use the default ICMP monitor that the
Local Traffic Manager provides.

You can test a custom monitor configuration against a specified target destination by using the run command,
and view the results of such a test by using the show command with the test-result option.

The following user roles (in addition to the root user) have permissions to run and stop an ltm monitor test:

admin, application-editor, manager, operator, resource-admin

EXAMPLES
create icmp my_icmp defaults-from icmp

Creates a monitor named my_icmp that inherits properties from the default ICMP monitor.

list icmp

Displays the properties of all of the ICMP monitors.

run icmp my_icmp destination 10.10.10.10

Runs a one-shot test of the custom monitor my_icmp against a target node at IP address 10.10.10.10.

stop icmp my_icmp

Cancels a one-shot test of the custom monitor my_icmp in progress.

show icmp my_icmp test-result

Displays the result of the most recent one-shot test of the custom monitor my_icmp.

OPTIONS
adaptive
Specifies whether the adaptive feature is enabled for this monitor. Not all monitors support the adaptive
feature.

adaptive-divergence-type
Specifies whether the adaptive-divergence-value is relative or absolute.

adaptive-divergence-value
Specifies how far from mean latency each monitor probe is allowed to be. If adaptive-divergence-type is
relative, this value is a percentage deviation from mean (e.g. 50 would indicate the probe is allowed to
exceed the mean latency by 50%.) If adaptive-divergence-type is absolute, this value is an offset from
mean in milliseconds (e.g. 250 would indicate the probe is allowed allowed to exceed the mean latency by
250 ms.) A probe that exceeds latency is counted the same as a probe that is not received, so in the
typical scenario, it will require three missed latencies in a row to mark a pool member or node down
(i.e. a 15-second interval with a 46-second timeout, would require three missed probes before the pool
member or node would be marked down.)

adaptive-limit
Specifies the hard limit, in milliseconds, which the probe is not allowed to exceed, regardless of the
divergence value. For example, if this value is 500, then the probe latency may not exceed 500 ms even if
that would still fall within the divergence value.

adaptive-sampling-timespan
Specifies the size of the sliding window, in seconds, which records probe history. For example, if this
value is 300, then a sliding window of the last five minutes' probe history will be used for calculating
probe mean latency and standard deviation.

app-service
Specifies the name of the application service to which the monitor belongs. The default value is none.
Note: If the strict-updates option is enabled on the application service that owns the object, you cannot
modify or delete the monitor. Only the application service can modify or delete the monitor.

defaults-from
Specifies the name of the monitor from which you want your custom monitor to inherit settings. The
default value is icmp.

description
User defined description.

destination
Specifies the IP address of the resource that is the destination of this monitor. The default value is *.

Possible values are:

* Specifies to perform a health check on the IP address of the node.

IP address
Specifies to perform a health check on the IP address that you specify, and mark the associated node
up or down accordingly.

IP address (with the transparent option enabled)
Specifies to perform a health check on the IP address that you specify, route the check through the
IP address of the associated node, and mark the IP address of the associated node up or down
accordingly.

This option is required for the command run, unless an IP address is specified in the destination option
for the custom monitor.

glob Displays the items that match the glob expression. See help glob for a description of glob expression
syntax.

interval
Specifies, in seconds, the frequency at which the system issues the monitor check when either the
resource is down or the status of the resource is unknown. The default value is 5 seconds.

Important: F5 Networks recommends that when you configure this option and the up-interval option,
whichever value is greater be a multiple of the lesser value to allow for an even distribution of monitor
checks among all monitors.

manual-resume
Specifies whether the system automatically changes the status of a resource to up at the next successful
monitor check. The default value of the manual-resume option is disabled.

Note that if you set the manual-resume option to enabled, you must manually mark the resource as up
before the system can use it for load balancing connections.

name Specifies a unique name for the component. This option is required for the commands create, delete,
modify, run and stop.

partition
Displays the administrative partition within which the component resides.

regex
Displays the items that match the regular expression. The regular expression must be preceded by an at
sign (@[regular expression]) to indicate that the identifier is a regular expression. See help regex for
a description of regular expression syntax.

test-result
Displays the result of the most recent one-shot test of the specified monitor(s), if any such test has
been performed since BIG-IP was started.

time-until-up
Specifies the amount of time, in seconds, after the first successful response before a node is marked up.
A value of 0 (zero) causes a node to be marked up immediately after a valid response is received from the
node. The default value is 0 (zero).

timeout
Specifies the number of seconds the target has in which to respond to the monitor request. The default
value is 16 seconds.

If the target responds within the set time period, it is considered up. If the target does not respond
within the set time period, it is considered down. Also, if the target responds with a RESET packet, the
system immediately flags the target as down without waiting for the timeout interval to expire.

transparent
Specifies whether the monitor operates in transparent mode. Monitors in transparent mode can monitor pool
members through firewalls. The default value is disabled.

up-interval
Specifies, in seconds, the frequency at which the system issues the monitor check when the resource is
up. The default value is 0 (zero), which specifies that the system uses the value of the interval option
whether the resource is up or down.

Important: F5 Networks recommends that when you configure this option and the interval option, whichever
value is greater be a multiple of the lesser value to allow for an even distribution of monitor checks
among all monitors.

SEE ALSO
create, delete, edit, glob, list, modify, regex, run, show, stop, tmsh

COPYRIGHT
No part of this program may be reproduced or transmitted in any form or by any means, electronic or
mechanical, including photocopying, recording, or information storage and retrieval systems, for any purpose
other than the purchaser's personal use, without the express written permission of F5 Networks, Inc.

BIG-IP 2017-04-05 ltm monitor icmp(1)