NAME

       iperf - perform network throughput tests

SYNOPSIS

       iperf -s [ options ]

       iperf -c server [ options ]

       iperf -u -s [ options ]

       iperf -u -c server [ options ]

DESCRIPTION

       iperf  is  a  tool  for  performing  network  throughput  measurements.   It  can  test either TCP or UDP
       throughput.  To perform an iperf test the user must establish both a server (to discard  traffic)  and  a
       client (to generate traffic).

GENERAL OPTIONS

       -e, --enhanced
              Display enhanced output in reports

       -f, --format
              [kmgKMG]   format to report: Kbits, Mbits, KBytes, MBytes (see NOTES for more)

       -h, --help
              print a help synopsis

       -i, --interval n
              pause n seconds between periodic bandwidth reports

       -l, --len n[kmKM]
              set read/write buffer size (TCP) or length (UDP) to n (TCP default 128K, UDP default 1470)

       -m, --print_mss
              print TCP maximum segment size (MTU - TCP/IP header)

       -o, --output filename
              output the report or error message to this specified file

       -p, --port n
              set server port to listen on/connect to to n (default 5001)

       -u, --udp
              use UDP rather than TCP

           --udp-counters-64bit
              use 64 bit UDP sequence numbers

       -w, --window n[kmKM]
              TCP window size (socket buffer size)

       -z, --realtime
              Request realtime scheduler, if supported.

       -B, --bind host
              bind to host, an interface or multicast address

       -C, --compatibility
              for use with older versions does not sent extra msgs

       -M, --mss n
              set TCP maximum segment size (MTU - 40 bytes)

       -N, --nodelay
              set TCP no delay, disabling Nagle's Algorithm

       -S, --tos
              set the socket's IP_TOS (byte) field

       -v, --version
              print version information and quit

       -x, --reportexclude [CDMSV]
              exclude C(connection) D(data) M(multicast) S(settings) V(server) reports

       -y, --reportstyle C|c
              if set to C or c report results as CSV (comma separated values)

SERVER SPECIFIC OPTIONS

       -s, --server
              run in server mode

       -D, --daemon
              run the server as a daemon.  On Windows this will also install the IPerfService.

       -R, --remove
              remove the IPerfService (Windows only).

       -U, --single_udp
              run in single threaded UDP mode

       -V, --ipv6_domain
              Enable  IPv6  reception by setting the domain and socket to AF_INET6 (Can receive on both IPv4 and
              IPv6)

CLIENT SPECIFIC OPTIONS

       -b, --bandwidth n[kmgKMG] | npps
              set target bandwidth to n bits/sec (default 1 Mbit/sec) or n packets per sec.  This  may  be  used
              with TCP or UDP.

       -c, --client host
              run in client mode, connecting to host

       -d, --dualtest
              Do a bidirectional test simultaneously

       -n, --num n[kmKM]
              number of bytes to transmit (instead of -t)

       -r, --tradeoff
              Do a bidirectional test individually

       -t, --time n
              time  in  seconds  to  listen  for  new  traffic  connections, receive traffic or transmit traffic
              (Defaults: transmit is 10 secs while listen and receive are indefinite)

       -B, --bind ip | ip:port | ipv6 -V | [ipv6]:port -V
              bind src addr(s) and ports from which to originate traffic (Note: -V option required for ipv6)

       -F, --fileinput name
              input the data to be transmitted from a file

       -I, --stdin
              input the data to be transmitted from stdin

       -L, --listenport n
              port to receive bidirectional tests back on

       -P, --parallel n
              number of parallel client threads to run

       -R, --reverse
              reverse the traffic flow after header exchange, useful for testing through firewalls

       -T, --ttl n
              time-to-live, for multicast (default 1)

       -V, --ipv6_domain
              Set the domain to IPv6 (send packets over IPv6)

       -X, --peerdetect
              run server version detection prior to traffic.

       -Z, --linux-congestion algo
              set TCP congestion control algorithm (Linux only)

ENVIRONMENT

       TCP_WINDOW_SIZE
              Controls the size of TCP buffers.

NOTES

       Some numeric options support format characters per '<value>c' (e.g. 10M) where the  c  format  characters
       are k,m,g,K,M,G.  Lowercase format characters are 10^3 based and uppercase are 2^n based, e.g. 1k = 1000,
       1K = 1024, 1m = 1,000,000 and 1M = 1,048,576

DIAGNOSTICS

       This section needs to be filled in.

BUGS

       See https://sourceforge.net/p/iperf2/tickets/

AUTHORS

       Iperf2,  based  from  iperf  (originally  written  by  Mark  Gates  and  Alex  Warshavsky), has a goal of
       maintenance with some feature enhancement.  Other contributions from Ajay  Tirumala,  Jim  Ferguson,  Jon
       Dugan  <jdugan  at  x1024  dot  net>,  Feng Qin, Kevin Gibbs, John Estabrook <jestabro at ncsa.uiuc.edu>,
       Andrew Gallatin <gallatin at gmail.com>, Stephen  Hemminger  <shemminger  at  linux-foundation.org>,  Tim
       Auckland, Robert J. McMahon <rjmcmahon at rjmcmahon.com>

SEE ALSO

       http://sourceforge.net/projects/iperf2/

NLANR/DAST                                         APRIL 2008                                           IPERF(1)