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> usec

       -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, 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] 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

       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
       2023-12-22.  (At that time, the date of the most recent commit
       that was found in the repository was 2023-12-20.)  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)