bionic (8) ifpps.8.gz

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/.