ipfstat - reports on packet filter statistics and filter list
ipfstat [ -6aAdfghIilnoRsv ]
ipfstat -t [ -6C ] [ -D <addrport> ] [ -P
  <protocol> ] [ -S <addrport> ] [ -T <refresh
  time> ]
ipfstat examines /dev/kmem using the symbols _fr_flags,
  _frstats, _filterin, and _filterout. To run and work, it
  needs to be able to read both /dev/kmem and the kernel itself. The kernel name
  defaults to /vmunix.
The default behaviour of ipfstat is to retrieve and display
    the accumulated statistics which have been accumulated over time as the
    kernel has put packets through the filter.
  - -6
- Display filter lists and states for IPv6, if available.
- -a
- Display the accounting filter list and show bytes counted against each
      rule.
- -A
- Display packet authentication statistics.
- -C
- This option is only valid in combination with -t. Display
      "closed" states as well in the top. Normally, a TCP connection
      is not displayed when it reaches the CLOSE_WAIT protocol state. With this
      option enabled, all state entries are displayed.
- -d
- Produce debugging output when displaying data.
- -D <addrport>
- This option is only valid in combination with -t. Limit the state
      top display to show only state entries whose destination IP address and
      port match the addrport argument. The addrport specification is of the
      form ipaddress[,port]. The ipaddress and port should be either numerical
      or the string "any" (specifying any IP address resp. any port).
      If the -D option is not specified, it defaults to "-D
      any,any".
- -f
- Show fragment state information (statistics) and held state information
      (in the kernel) if any is present.
- -g
- Show groups currently configured (both active and inactive).
- -h
- Show per-rule the number of times each one scores a "hit". For
      use in combination with -i.
- -i
- Display the filter list used for the input side of the kernel IP
      processing.
- -I
- Swap between retrieving "inactive"/"active" filter
      list details. For use in combination with -i.
- -n
- Show the "rule number" for each rule as it is printed.
- -o
- Display the filter list used for the output side of the kernel IP
      processing.
- -P <protocol>
- This option is only valid in combination with -t. Limit the state
      top display to show only state entries that match a specific protocol. The
      argument can be a protocol name (as defined in /etc/protocols) or a
      protocol number. If this option is not specified, state entries for any
      protocol are specified.
- -R
- Don't try to resolve addresses to hostnames and ports to services while
      printing statistics.
- -s
- Show packet/flow state information (statistics only).
- -sl
- Show held state information (in the kernel) if any is present (no
      statistics).
- -S <addrport>
- This option is only valid in combination with -t. Limit the state
      top display to show only state entries whose source IP address and port
      match the addrport argument. The addrport specification is of the form
      ipaddress[,port]. The ipaddress and port should be either numerical or the
      string "any" (specifying any IP address resp. any port). If the
      -S option is not specified, it defaults to "-S
      any,any".
- -t
- Show the state table in a way similar to the way top(1) shows the
      process table. States can be sorted using a number of different ways. This
      option requires curses(3) and needs to be compiled in. It may not
      be available on all operating systems. See below, for more information on
      the keys that can be used while ipfstat is in top mode.
- -T <refreshtime>
- This option is only valid in combination with -t. Specifies how
      often the state top display should be updated. The refresh time is the
      number of seconds between an update. Any positive integer can be used. The
      default (and minimal update time) is 1.
- -v
- Turn verbose mode on. Displays more debugging information. When used with
      either -i or -o, counters associated with the rule, such as
      the number of times it has been matched and the number of bytes from such
      packets is displayed. For "keep state" rules, a count of the
      number of state sessions active against the rule is also displayed.
The role of ipfstat is to display current kernel statistics gathered as a
  result of applying the filters in place (if any) to packets going in and out
  of the kernel. This is the default operation when no command line parameters
  are present.When supplied with either -i or -o, it will retrieve
    and display the appropriate list of filter rules currently installed and in
    use by the kernel.
One of the statistics that ipfstat shows is ticks.
    This number indicates how long the filter has been enabled. The number is
    incremented every half-second.
Using the -t option ipfstat will enter the state top mode. In this
  mode the state table is displayed similar to the way top displays the
  process table. The -C, -D, -P, -S and -T
  command line options can be used to restrict the state entries that will be
  shown and to specify the frequency of display updates.
In state top mode, the following keys can be used to influence the
    displayed information:
  - b show packets/bytes from backward direction.
- f show packets/bytes from forward direction. (default)
- l redraw the screen.
- q quit the program.
- s switch between different sorting criterion.
- r reverse the sorting criterion.
States can be sorted by protocol number, by number of IP packets,
    by number of bytes and by time-to-live of the state entry. The default is to
    sort by the number of bytes. States are sorted in descending order, but you
    can use the r key to sort them in ascending order.
It is currently not possible to interactively change the source, destination and
  protocol filters or the refresh frequency. This must be done from the command
  line.
The screen must have at least 80 columns. This is however not
    checked. When running state top in IPv6 mode, the screen must be much wider
    to display the very long IPv6 addresses.
Only the first X-5 entries that match the sort and filter criteria
    are displayed (where X is the number of rows on the display. The only way to
    see more entries is to resize the screen.
/dev/kmem
/dev/ipl
/dev/ipstate
/vmunix