ltm monitor tcp
ltm monitor tcp(1) BIG-IP TMSH Manual ltm monitor tcp(1)
NAME
tcp - Configures a Transmission Control Protocol (TCP) monitor.
MODULE
ltm monitor
SYNTAX
Configure the tcp component within the ltm monitor module using the
syntax in the following sections.
CREATE/MODIFY
create tcp [name]
modify tcp [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][port]
interval [integer]
ip-dscp [integer]
manual-resume [enabled | disabled]
recv [none | [string] ]
recv-disable [none | [string] ]
reverse [enabled | disabled]
send [none | [string] ]
time-until-up [integer]
timeout [integer]
transparent [disabled | enabled]
up-interval [integer]
edit tcp [ [ [name] | [glob] | [regex] ] ... ]
options:
all-properties
non-default-properties
DISPLAY
list tcp
list tcp [ [ [name] | [glob] | [regex] ] ... ]
show tcp [ [ [name] | [glob] | [regex] ] ... ]
show running-config tcp
show running-config tcp [ [ [name] | [glob] | [regex] ] ... ]
options:
all-properties
non-default-properties
one-line
partition
DELETE
delete tcp [name]
Note: You cannot delete default monitors.
DESCRIPTION
You can use the tcp component to configure a custom monitor, or you can
use the default TCP monitor that the Local Traffic Manager provides.
EXAMPLES
create tcp my_tcp defaults-from tcp
Creates a monitor named my_tcp that inherits properties from the
default TCP monitor.
list tcp
Displays the properties of all of the TCP monitors.
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 tcp.
description
User defined description.
destination
Specifies the IP address and service port 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 and
port supplied by a pool member.
*:port
Specifies to perform a health check on the server with the IP
address supplied by the pool member and the port you specify.
IP address:port
Specifies to mark a pool member up or down based on the
response of the server at the IP address and port you
specify.
IP address:port (with the transparent option enabled)
Specifies to perform a health check on the server at the IP
address and port you specify, route the check through the IP
address and port supplied by the pool member, and mark the
pool member (the gateway) up or down accordingly.
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.
ip-dscp
Specifies the differentiated services code point (DSCP). DSCP is a
6-bit value in the Differentiated Services (DS) field of the IP
header. It can be used to specify the quality of service desired
for the packet. The valid range for this value is 0 to 63 (hex 0x0
to 0x3f). The default value is zero.
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, and modify.
partition
Displays the administrative partition within which the component
resides.
recv Specifies the text string that the monitor looks for in the
returned resource. The default value is none.
The most common receive expressions contain a text string that is
included in an HTML file on your site. The text string can be
regular text, HTML tags, or image names. If you do not specify a
value for both the send and recv options, the monitor performs a
simple service check and connect only.
recv-disable
Specifies a text string that the monitor looks for in the returned
resource. If the text string is matched in the returned resource,
the corresponding node or pool member is marked session disabled.
The default value is none.
You specify a recv-disable string in the same way that you specify
a recv string.
If you specify a recv-disable string, you must also specify a recv
string. You cannot specify a recv-disable string, if the reverse
option is enabled.
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.
reverse
Specifies whether the monitor operates in reverse mode. When the
monitor is in reverse mode, a successful check marks the monitored
object down instead of up. You can use the this mode only if you
configure both the send and recv options.
The default value is disabled, which specifies that the monitor
does not operate in reverse mode. The enabled value specifies that
the monitor operates in reverse mode.
send Specifies the text string that the monitor sends to the target
object. The default setting is GET /, which retrieves a default
HTML file for a web site.
To retrieve a specific page from a web site, specify a fully-
qualified path name, for example, GET /www/company/index.html.
Since the string may have special characters, the system may
require that the string be enclosed with single quotation marks.
If this value is null, then a valid connection suffices to
determine that the service is up. In this case, the system does
not need the recv option and ignores the option even if not null.
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, show, tmsh
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BIG-IP 2016-03-14 ltm monitor tcp(1)