ip-monitor(8) — Linux manual page


IP-MONITOR(8)                       Linux                      IP-MONITOR(8)

NAME         top

       ip-monitor, rtmon - state monitoring

SYNOPSIS         top

       ip monitor [ all | OBJECT-LIST ] [ file FILENAME ] [ label ] [ all-
               nsid ] [ dev DEVICE ]

OPTIONS         top

       -t, -timestamp
              Prints timestamp before the event message on the separated
              line in format:
                  Timestamp: <Day> <Month> <DD> <hh:mm:ss> <YYYY> <usecs>

       -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         top

       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 and nsid.  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] 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] 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         top


AUTHOR         top

       Original Manpage by Michail Litvak <mci@owl.openwall.com>
       Manpage revised by Nicolas Dichtel <nicolas.dichtel@6wind.com>

COLOPHON         top

       This page is part of the iproute2 (utilities for controlling TCP/IP
       networking and traffic) project.  Information about the project can
       be found at 
       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
       2020-08-13.  (At that time, the date of the most recent commit that
       was found in the repository was 2020-06-24.)  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

iproute2                         13 Dec 2012                   IP-MONITOR(8)

Pages that refer to this page: ip(8)