.TH IP\-MONITOR 8 "13 Dec 2012" "iproute2" "Linux"

.SH "NAME"

ip-monitor, rtmon \- state monitoring

.SH "SYNOPSIS"

.sp

.ad l

.in +8

.ti -8

.BR "ip monitor" " [ " all " |"

.IR OBJECT-LIST " ] ["

.BI file " FILENAME "

] [

.BI label

] [

.BI all-nsid

] [

.BI dev " DEVICE "

]

.sp

.SH OPTIONS

.TP

.BR "\-t" , " \-timestamp"

Prints timestamp before the event message on the separated line in format:

    Timestamp: <Day> <Month> 
 <hh:mm:ss> <YYYY> <usecs> usec

    <EVENT>

.TP

.BR "\-ts" , " \-tshort"

Prints short timestamp before the event message on the same line in format:

    [<YYYY>-<MM>-
T<hh:mm:ss>.<ms>] <EVENT>

.SH DESCRIPTION

The

.B ip

utility can monitor the state of devices, addresses

and routes continuously. This option has a slightly different format.

Namely, the

.B monitor

command is the first in the command line and then the object list follows:

.BR "ip monitor" " [ " all " |"

.IR OBJECT-LIST " ] ["

.BI file " FILENAME "

] [

.BI label

] [

.BI all-nsid

] [

.BI dev " DEVICE "

]

.I OBJECT-LIST

is the list of object types that we want to monitor.

It may contain

.BR link ", " address ", " route ", " mroute ", " prefix ", "

.BR neigh ", " netconf ", "  rule " and " nsid "."

If no

.B file

argument is given,

.B ip

opens RTNETLINK, listens on it and dumps state changes in the format

described in previous sections.

.P

If the

.BI label

option is set, a prefix is displayed before each message to

show the family of the message. For example:

.sp

.in +2

[NEIGH]10.16.0.112 dev eth0 lladdr 00:04:23:df:2f:d0 REACHABLE

[LINK]3: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN group default

    link/ether 52:54:00:12:34:57 brd ff:ff:ff:ff:ff:ff

.in -2

.sp

.P

If the

.BI all-nsid

option is set, the program listens to all network namespaces that have a

nsid assigned into the network namespace were the program is running.

A prefix is displayed to show the network namespace where the message

originates. Example:

.sp

.in +2

[nsid 0]10.16.0.112 dev eth0 lladdr 00:04:23:df:2f:d0 REACHABLE

.in -2

.sp

.P

If the

.BI file

option is given, the program does not listen on RTNETLINK,

but opens the given file, and dumps its contents. The file

should contain RTNETLINK messages saved in binary format.

Such a file can be generated with the

.B rtmon

utility. This utility has a command line syntax similar to

.BR "ip monitor" .

Ideally,

.B rtmon

should be started before the first network configuration command

is issued. F.e. if you insert:

.sp

.in +8

rtmon file /var/log/rtmon.log

.in -8

.sp

in a startup script, you will be able to view the full history

later.

.P

Nevertheless, it is possible to start

.B rtmon

at any time.

It prepends the history with the state snapshot dumped at the moment

of starting.

.P

If the

.BI dev

option is given, the program prints only events related to this device.

.SH SEE ALSO

.br

.BR ip (8)

.SH AUTHOR

Original Manpage by Michail Litvak <mci@owl.openwall.com>

.br

Manpage revised by Nicolas Dichtel <nicolas.dichtel@6wind.com>