IPMON(8)                                                              IPMON(8)

       ipmon - monitors /dev/ipl for logged packets

       ipmon [ -abBDFhnpstvxX ] [ -N <device> ] [ -L <facility> ] [ -o [NSI] ]
       [ -O [NSI] ] [ -P <pidfile> ] [ -S <device> ] [ -f <device> ] [  <file-
       name> ]

       ipmon  opens  /dev/ipl for reading and awaits data to be saved from the
       packet filter.  The binary data read from the device  is  reprinted  in
       human  readable  for,  however, IP#'s are not mapped back to hostnames,
       nor are ports mapped back to service names.  The output goes  to  stan-
       dard  output  by  default  or a filename, if given on the command line.
       Should the -s option be used, output is  instead  sent  to  syslogd(8).
       Messages  sent via syslog have the day, month and year removed from the
       message, but the time (including microseconds), as recorded in the log,
       is still included.

       Messages  generated  by  ipmon  consist of whitespace separated fields.
       Fields common to all messages are:

       1. The date of packet receipt. This is suppressed when the  message  is
       sent to syslog.

       2.  The  time  of  packet  receipt. This is in the form HH:MM:SS.F, for
       hours, minutes seconds, and fractions of a second (which can be several
       digits long).

       3. The name of the interface the packet was processed on, e.g., we1.

       4.  The  group  and  rule number of the rule, e.g., @0:17. These can be
       viewed with ipfstat -n.

       5. The action: p for passed, b for blocked,  for a short packet, n  did
       not match any rules or L for a log rule.

       6.  The  addresses.   This is actually three fields: the source address
       and port (separated by a comma), the ->  symbol,  and  the  destination
       address and port. E.g.:,80 ->,1722.

       7. PR followed by the protocol name or number, e.g., PR tcp.

       8.  len  followed  by the header length and total length of the packet,
       e.g., len 20 40.

       If the packet is a TCP packet, there will be an additional field start-
       ing  with  a hyphen followed by letters corresponding to any flags that
       were set.  See the ipf.conf manual page for a list of letters and their

       If  the  packet is an ICMP packet, there will be two fields at the end,
       the first always being `icmp', and the next being the ICMP message  and
       submessage  type,  separated  by  a  slash,  e.g.,  icmp 3/3 for a port
       unreachable message.

       In order for ipmon to properly work,  the  kernel  option  IPFILTER_LOG
       must  be  turned  on  in  your  kernel.  Please see options(4) for more

       ipmon reopens its log file(s) and rereads its configuration  file  when
       it receives a SIGHUP signal.

       -a     Open  all  of  the device logfiles for reading log entries from.
              All entries are displayed to the same output 'device' (stderr or

       -b     For  rules  which  log the body of a packet, generate hex output
              representing the packet contents after the headers.

       -B <binarylogfilename>
              Enable logging of the raw, unformatted binary data to the speci-
              fied  <binarylogfilename>  file.  This can be read, later, using
              ipmon with the -f option.

       -D     Cause ipmon to turn itself into a daemon.   Using  subshells  or
              backgrounding of ipmon is not required to turn it into an orphan
              so it can run indefinitely.

       -f <device>
              specify an alternative device/file from which to  read  the  log
              information for normal IP Filter log records.

       -F     Flush  the  current  packet  log  buffer.   The  number of bytes
              flushed is displayed, even should the result be zero.

       -L <facility>
              Using this option allows you to change the default syslog facil-
              ity that ipmon uses for syslog messages.  The default is local0.

       -n     IP addresses and port numbers will be  mapped,  where  possible,
              back into hostnames and service names.

       -N <device>
              Set the logfile to be opened for reading NAT log records from to

       -o     Specify which log files to actually read data  from.   N  -  NAT
              logfile,  S  - State logfile, I - normal IP Filter logfile.  The
              -a option is equivalent to using -o NSI.

       -O     Specify which log files you do not wish to read from.   This  is
              most sensibly used with the -a.  Letters available as parameters
              to this are the same as for -o.

       -p     Cause the port number in log messages to always be printed as  a
              number  and  never  attempt to look it up as from /etc/services,

       -P <pidfile>
              Write the pid of the ipmon process to a file.  By  default  this
              is  //etc/opt/ipf/ipmon.pid (Solaris), /var/run/ipmon.pid (44BSD
              or later) or /etc/ipmon.pid for all others.

       -s     Packet information read in will be sent through  syslogd  rather
              than  saved  to  a file.  The default facility when compiled and
              installed is local0.  The following levels are used:

              LOG_INFO - packets logged using the "log" keyword as the  action
              rather than pass or block.

              LOG_NOTICE - packets logged which are also passed

              LOG_WARNING - packets logged which are also blocked

              LOG_ERR  -  packets which have been logged and which can be con-
              sidered "short".

       -S <device>
              Set the logfile to be opened for reading state log records  from
              to <device>.

       -t     read the input file/device in a manner akin to tail(1).

       -v     show tcp window, ack and sequence fields.

       -x     show the packet data in hex.

       -X     show the log header record data in hex.

       ipmon expects data that it reads to be consistent with how it should be
       saved and will abort if it fails an assertion which detects an  anomaly
       in the recorded data.


       ipl(4), ipf(8), ipfstat(8), ipnat(8)

       If you find any, please send email to me at darrenr@pobox.com