NAME¶
iperf3 - perform network throughput tests
SYNOPSIS¶
iperf3 -s [ options ]
iperf3 -c server [ options ]
DESCRIPTION¶
iperf3 is a tool for performing network throughput measurements. It can test
either TCP or UDP throughput. To perform an iperf3 test the user must
establish both a server and a client.
GENERAL OPTIONS¶
- -p, --port n
- set server port to listen on/connect to to n (default 5201)
- -f, --format
- [kmKM] format to report: Kbits, Mbits, KBytes, MBytes
- -i, --interval n
- pause n seconds between periodic bandwidth reports; default is 1,
use 0 to disable
- -F, --file name
- client-side: read from the file and write to the network, instead of using
random data; server-side: read from the network and write to the file,
instead of throwing the data away
- -A, --affinity n/n,m
- Set the CPU affinity, if possible (linux only). On both the client and
server you can set the local affinity; in addition, on the client side you
can override the server's affinity for just that one test, using the n,m
form.
- -V, --verbose
- give more detailed output
- -J, --json
- output in JSON format
- -d, --debug
- emit debugging output. Primarily (perhaps exclusively) of use to
developers.
- -v, --version
- show version information and quit
- -h, --help
- show a help synopsis
SERVER SPECIFIC OPTIONS¶
- -s, --server
- run in server mode
- -D, --daemon
- run the server in background as a daemon
CLIENT SPECIFIC OPTIONS¶
- -c, --client host
- run in client mode, connecting to the specified server
- -u, --udp
- use UDP rather than TCP
- -b, --bandwidth n[KM]
- set target bandwidth to n bits/sec (default 1 Mbit/sec for UDP,
unlimited for TCP). If there are multiple streams (-P flag), the bandwidth
limit is applied separately to each stream. You can also add a '/' and a
number to the bandwidth specifier. This is called "burst mode".
It will send the given number of packets without pausing, even if that
temporarily exceeds the specified bandwidth limit. Setting the target
bandwidth to 0 will disable bandwidth limits (particularly useful for UDP
tests).
- -t, --time n
- time in seconds to transmit for (default 10 secs)
- -n, --bytes n[KM]
- number of bytes to transmit (instead of -t)
- -k, --blockcount n[KM]
- number of blocks (packets) to transmit (instead of -t or -n)
- -l, --length n[KM]
- length of buffer to read or write (default 128 KB for TCP, 8KB for
UDP)
- -P, --parallel n
- number of parallel client streams to run
- -R, --reverse
- run in reverse mode (server sends, client receives)
- -w, --window n[KM]
- TCP window size / socket buffer size (this gets sent to the server and
used on that side too)
- -B, --bind n[KM]
- bind to a specific interface or multicast address
- -M, --set-mss n
- set TCP maximum segment size (MTU - 40 bytes)
- -N, --no-delay
- set TCP no delay, disabling Nagle's Algorithm
- -4, --version4
- only use IPv4
- -6, --version6
- only use IPv6
- -S, --tos n
- set the IP 'type of service'
- -L, --flowlabel n
- set the IPv6 flow label (currently only supported on Linux)
- -Z, --zerocopy
- Use a "zero copy" method of sending data, such as sendfile(2),
instead of the usual write(2).
- -O, --omit n
- Omit the first n seconds of the test, to skip past the TCP slow-start
period.
- -T, --title str
- Prefix every output line with this string.
- -C, --linux-congestion algo
- Set the congestion control algorithm (linux only).
- --get-server-output
- Get the output from the server. The output format is determined by the
server (in particular, if the server was invoked with the --json
flag, the output will be in JSON format, otherwise it will be in
human-readable format). If the client is run with --json, the
server output is included in a JSON object; otherwise it is appended at
the bottom of the human-readable output.
AUTHORS¶
Iperf 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>, Stephen Hemminger <shemminger at linux-foundation.org>
SEE ALSO¶
libiperf(3),
http://software.es.net/iperf