NAME

       ifpps - top-like networking and system statistics

SYNOPSIS

       ifpps { [options] | [device] }

DESCRIPTION

       ifpps  is  a  small  utility  which  periodically  provides top-like networking and system
       statistics from the kernel. ifpps gathers its data directly from procfs files and does not
       make  use of any user space monitoring libraries which would falsify statistics under high
       load.

       For instance, consider the following scenario: two directly connected Linux machines  with
       Intel  Core  2  Quad Q6600 2.40GHz CPUs, 4 GB RAM, and an Intel 82566DC-2 Gigabit Ethernet
       NIC are used for performance evaluation.  One machine generates 64 byte network packets by
       using  the  kernel  space packet generator pktgen with a maximum possible packet rate. The
       other machine displays statistics about incoming network packets by using i) iptraf(8) and
       ii) ifpps.

       iptraf which incorporates pcap(3) shows an average packet rate of 246,000 pps while on the
       other hand ifpps shows an average packet rate of  1,378,000  pps.  Hence,  due  to  packet
       copies  and  deferring  statistics  creation  into  user  space,  a  measurement  error of
       approximately 460 percent occurs. Tools like iptraf might display  much  more  information
       such  as TCP per flow statistics (hence the use of the pcap library). This is not possible
       with ifpps, because overall networking statistics are its  focus;  statistics,  which  are
       also fairly reliable under high packet load.

       ifpps  also  periodically displays CPU load, interrupt, software interrupt data per sample
       interval as well as total interrupts, all per CPU. In case the number of CPUs exceeds 5 or
       the  number  specified  by  the  user  with  the “-n” command line option, ifpps will only
       display this number top heavy hitters. The topmost heavy hitter CPU will  be  marked  with
       “+”.  The least heavy hitter will always be displayed and is marked with “-”. In addition,
       the average for all the above per-CPU data is shown. Optionally the median values  can  be
       displayed using the “-m” command line option.

       ifpps  also supports directly the gnuplot(1) data sample format. This facilitates creation
       of gnuplot figures from ifpps time series.

OPTIONS

   -d <netdev>, --dev <netdev>
       Networking device to fetch statistics from, for example eth0, wlan0.

   -n, --num-cpus
       Set maximum number of top hitter CPUs (in terms of time  spent  in  system/user  mode)  to
       display in ncurses mode, default is 10.

   -t <time>, --interval <time>
       Statistics refresh interval in milliseconds, default is 1000ms.

   -c, --csv
       Output (once) the ncurses data to the terminal as gnuplot(1)-ready data.

   -l, --loop
       Continuously  output  the  terminal  data  after  a  refresh interval. This option is only
       available if option “-c” is given. For “-l” it is  usually  recommended  to  redirect  the
       output into a file that is to be processed later with gnuplot(1).

   -m, --median
       Show  median  values  across all CPUs for CPU load, interrupts (per interval and absolute)
       and software interrupts.

   -o, --omit-header
       Omit printing the CSV header. This option is only available if “-c” is given.

   -p, --promisc
       Turn on promiscuous mode for the given networking device.

   -P, --percentage
       Show percentage of current throughput in relation to theoretical line rate.

   -W, --no-warn
       Suppress possible warnings in the ncurses output, e.g. about a too low  sampling  interval
       that could cause performance regression.

   -v, --version
       Show version information.

   -h, --help
       Show user help.

USAGE EXAMPLE

   ifpps eth0
       Default ncurses output for the eth0 device.

   ifpps -pd eth0
       Ncurses output for the eth0 device in promiscuous mode.

   ifpps -lpcd wlan0 > plot.dat
       Continuous terminal output for the wlan0 device in promiscuous mode.

NOTE

       On  10Gbit/s cards or higher, receive and transmit statistics are usually accumulated at a
       higher duration interval than 1 second. Thus, it might be advisable to alter the timing to
       a higher accumulation interval for such cards.

LEGAL

       ifpps is licensed under the GNU GPL version 2.0.

HISTORY

       ifpps  was  originally  written  for  the  netsniff-ng  toolkit  by Daniel Borkmann. It is
       currently  maintained  by  Tobias  Klauser  <tklauser@distanz.ch>  and   Daniel   Borkmann
       <dborkma@tik.ee.ethz.ch>.

SEE ALSO

       netsniff-ng(8),    trafgen(8),   mausezahn(8),   bpfc(8),   flowtop(8),   astraceroute(8),
       curvetun(8)

AUTHOR

       Manpage was written by Daniel Borkmann.

COLOPHON

       This page is part of the Linux netsniff-ng toolkit project. A description of the  project,
       and information about reporting bugs, can be found at http://netsniff-ng.org/.