iperf2

Runs on:

QNX Neutrino

Options:

The general options include:

-B host

--bind host

Bind to host, an interface or multicast address.

-C

--compatibility

For use with older versions; don't send extra msgs.

-f k|m|K|M

--format k|m|K|M

The format to report: Kbits, Mbits, KBytes, MBytes.

-h

--help

Print a help synopsis.

-i n

--interval n

Pause for n seconds between periodic bandwidth reports.

-l n[K|M]

--len n[K|M]

Set the length of the read/write buffer to n (default 8 KB).

-M n

--mss n

Set the TCP maximum segment size (MTU - 40 bytes).

-m

--print_mss

Print the TCP maximum segment size (MTU - TCP/IP header).

-N

--nodelay

Set TCP no delay, disabling Nagle's Algorithm.

-o filename

--output filename

Output the report or error message to the specified file.

-p n

--port n

Set the server port to listen on/connect to to n (default 5001).

-u

--udp

Use UDP rather than TCP.

-v

--version

Print version information, and then exit.

-V

--IPv6Version

Set the domain to IPv6.

-w n[K|M]

--window n[K|M]

Set the TCP window size (socket buffer size).

-x C|D|M|S|V

--reportexclude C|D|M|S|V

Exclude C(connection), D(data), M(multicast), S(settings), or V(server) reports.

-y C|c

--reportstyle C|c

If set to C or c, report results as CSV (comma-separated values).

The server-specific options include:

-D

--daemon

Run the server as a daemon.

-s

--server

Run in server mode.

-U

--single_udp

Run in single-threaded UDP mode.

The client-specific options include:

-b n[K|M]

--bandwidth n[K|M]

Set the target bandwidth to n bits/sec (default 1 Mbit/sec). This setting requires UDP (-u).

-c host

--client host

Run in client mode, connecting to host.

-d

--dualtest

Do a bidirectional test simultaneously.

-F name

--fileinput name

Input the data to be transmitted from a file.

-I

--stdin

Input the data to be transmitted from stdin.

-L n

--listenport n

The port to receive bidirectional tests back on.

-n n[K|M]

--num n[K|M]

The number of bytes to transmit (instead of -t).

-P n

--parallel n

The number of parallel client threads to run.

-r

--tradeoff

Do a bidirectional test individually.

-T n

--ttl n

The time-to-live, for multicast (default 1).

-t n

--time n

The time in seconds to transmit for (default 10 secs).

Description:

The iperf2 tool measures network throughput. It can test either TCP or UDP throughput. To perform an iperf2 test, you must establish both a server (to discard traffic) and a client (to generate traffic).

For a different version of this tool, see iperf3.

Environment variables:

TCP_WINDOW_SIZE

Controls the size of TCP buffers.

Contributing author:

iperf2 was originally written by Mark Gates and Alex Warshavsky. Man page and maintence by Jon Dugan jdugan at x1024 dot net. Other contributions from Ajay Tirumala, Jim Ferguson, Feng Qin, Kevin Gibbs, John Estabrook jestabro at ncsa.uiuc.edu, Andrew Gallatin gallatin at gmail.com>, and Stephen Hemminger shemminger at linux-foundation.org.

See also http://iperf2.sourceforge.net/.