Ubuntu Manpage: ifpps - top-like networking and system statistics

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>.

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/.

Linux                                             03 March 2013                                         IFPPS(8)