ip-monitor(8) — Linux manual page
IP-MONITOR(8) Linux IP-MONITOR(8)
NAME
ip-monitor, rtmon - state monitoring
SYNOPSIS
ip monitor [ all | OBJECT-LIST ] [ file FILENAME ] [ label ] [
all-nsid ] [ dev DEVICE ]
OPTIONS
-t, -timestamp
Prints timestamp before the event message on the separated
line in format:
Timestamp: <Day> <Month> <DD> <hh:mm:ss> <YYYY>
<usecs> usec
<EVENT>
-ts, -tshort
Prints short timestamp before the event message on the
same line in format:
[<YYYY>-<MM>-<DD>T<hh:mm:ss>.<ms>] <EVENT>
DESCRIPTION
The ip utility can monitor the state of devices, addresses and
routes continuously. This option has a slightly different format.
Namely, the monitor command is the first in the command line and
then the object list follows:
ip monitor [ all | OBJECT-LIST ] [ file FILENAME ] [ label ] [
all-nsid ] [ dev DEVICE ]
OBJECT-LIST is the list of object types that we want to monitor.
It may contain link, address, route, mroute, prefix, neigh,
netconf, rule, stats, nsid and nexthop. If no file argument is
given, ip opens RTNETLINK, listens on it and dumps state changes
in the format described in previous sections.
If the label option is set, a prefix is displayed before each
message to show the family of the message. For example:
[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
If the 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:
[nsid 0]10.16.0.112 dev eth0 lladdr 00:04:23:df:2f:d0 REACHABLE
If the 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 rtmon utility. This utility
has a command line syntax similar to ip monitor. Ideally, rtmon
should be started before the first network configuration command
is issued. F.e. if you insert:
rtmon file /var/log/rtmon.log
in a startup script, you will be able to view the full history
later.
Nevertheless, it is possible to start rtmon at any time. It
prepends the history with the state snapshot dumped at the moment
of starting.
If the dev option is given, the program prints only events
related to this device.
SEE ALSO
ip(8)
AUTHOR
Original Manpage by Michail Litvak <mci@owl.openwall.com>
Manpage revised by Nicolas Dichtel <nicolas.dichtel@6wind.com>
COLOPHON
This page is part of the iproute2 (utilities for controlling
TCP/IP networking and traffic) project. Information about the
project can be found at
⟨http://www.linuxfoundation.org/collaborate/workgroups/networking/iproute2⟩.
If you have a bug report for this manual page, send it to
netdev@vger.kernel.org, shemminger@osdl.org. This page was
obtained from the project's upstream Git repository
⟨https://git.kernel.org/pub/scm/network/iproute2/iproute2.git⟩ on
2024-06-14. (At that time, the date of the most recent commit
that was found in the repository was 2024-06-11.) If you
discover any rendering problems in this HTML version of the page,
or you believe there is a better or more up-to-date source for
the page, or you have corrections or improvements to the
information in this COLOPHON (which is not part of the original
manual page), send a mail to man-pages@man7.org
iproute2 13 Dec 2012 IP-MONITOR(8)
Pages that refer to this page: ip(8), rtmon(8)