man > ip-monitor(8)

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 op‐
       tion has a slightly different format.  Namely, the monitor command is the first in  the  com‐
       mand 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, ad‐
       dress, route, mroute, prefix, neigh, netconf, rule, stats, nsid and nexthop.  If no file  ar‐
       gument  is given, ip opens RTNETLINK, listens on it and dumps state changes in the format de‐
       scribed 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: <BROAD‐
         CAST,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 for‐
       mat.  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 con‐
       figuration 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 AT owl.com>
       Manpage revised by Nicolas Dichtel <nicolas.dichtel AT 6wind.com>

iproute2                                     13 Dec 2012                               IP-MONITOR(8)