ip-monitor, rtmon - state monitoring "ip monitor" " [ " all " |" LISTofOBJECTS " ]" 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 " |" LISTofOBJECTS " ]" OBJECT-LIST is the list of object types that we want to monitor. It may contain link ", " address " and " route "." If no file argument is given, ip opens RTNETLINK, listens on it and dumps state changes in the format described in previous sections.

If a file name is given, it does not listen on RTNETLINK, but opens the file containing RTNETLINK messages saved in binary format and dumps them. Such a history 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.

Certainly, it is possible to start rtmon at any time. It prepends the history with the state snapshot dumped at the moment of starting.

ip (8)

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