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Name

iperf - measure network performance

Synopsis

iperf [-s|-c host] [options]
iperf
[-h|--help] [-v|--version]

Description

Client/Server:

-f, --format
[kmKM] format to report: Kbits, Mbits, KBytes, MBytes
-i, --interval
# seconds between periodic bandwidth reports
-l, --len
#[KM] length of buffer to read or write (default 8 KB)
-m, --print_mss
print TCP maximum segment size (MTU - TCP/IP header)
-p, --port
# server port to listen on/connect to
-u, --udp
use UDP rather than TCP
-w, --window
#[KM] TCP window size (socket buffer size)
-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
# set TCP maximum segment size (MTU - 40 bytes)
-N, --nodelay
set TCP no delay, disabling Nagle’s Algorithm
-V, --IPv6Version
Set the domain to IPv6

Server specific:

-s, --server
run in server mode
-U, --single_udp
run in single threaded UDP mode
-D, --daemon
run the server as a daemon

Client specific:

-b, --bandwidth #[KM]
for UDP, bandwidth to send at in bits/sec (default 1 Mbit/sec, implies -u)
-c, --client
<host> run in client mode, connecting to <host>
-d, --dualtest
Do a bidirectional test simultaneously
-n, --num
#[KM] number of bytes to transmit (instead of -t)
-r, --tradeoff
Do a bidirectional test individually
-t, --time
# time in seconds to transmit for (default 10 secs)
-F, --fileinput <name>
input the data to be transmitted from a file
-I, --stdin
input the data to be transmitted from stdin
-L, --listenport #
port to recieve bidirectional tests back on
-P, --parallel
# number of parallel client threads to run
-T, --ttl
# time-to-live, for multicast (default 1)

Miscellaneous:

-h, --help
print this message and quit
-v, --version
print version information and quit

[KM] Indicates options that support a K or M suffix for kilo- or mega-

The TCP window size option can be set by the environment variable TCP_WINDOW_SIZE. Most other options can be set by an environment variable IPERF_<long option name>, such as IPERF_BANDWIDTH.

Reporting Bugs

Report bugs to <dast@nlanr.net>

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