iperf - perform network throughput tests
iperf -s [ options ]
iperf -c server [ options ]
iperf -u -s [ options ]
iperf -u -c server [ options
]
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).
- -b, --bandwidth
- set the target bandwidth (and optional standard devation where
supported)
- -e, --enhanced
- Display enhanced output in reports otherwise use legacy report (ver 2.0.5)
formatting (see notes)
- -f, --format
- [abkmgBKMG] format to report: adaptive, bits, Bytes, Kbits, Mbits, Gbits,
KBytes, MBytes, GBytes (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)
- --l2checks
- perform layer 2 length checks on received UDP packets (requires systems
that support packet sockets, e.g. Linux)
- -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, ip address or multicast address and optional port
(see notes)
- -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
- -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)
- -b, --bandwidth
n[kmgKMG]
- set target read rate to n bits/sec. TCP only for the server.
- -s, --server
- run in server mode
-
--udp-histogram[=binwidth[u],bincount,[lowerci],[upperci]]
- output UDP latency histograms, bin width (default 1 millisecond, append u
for microseconds,) bincount is total bins (default 1000), ci is confidence
interval between 0-100% (default lower 5%, upper 95%)
- -B, --bind
ip | ip%device
- bind src ip addr and optional src device for receiving
- -D, --daemon
- run the server as a daemon. On Windows this will also install the
IPerfService.
- -H, --ssm-host
host
- Set the source host (ip addr) per SSM multicast, i.e. the S of the
S,G
- -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)
- -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. For variable loads use
format mean,standard deviation
- -c, --client
host
- run in client mode, connecting to host
- -d, --dualtest
- Do a bidirectional test simultaneously
-
--incr-dstip
- increment the destination ip address when using the parallel (-P)
option
- --ipg n
- set the interpacket gap to n (units of milliseconds) for packets
within an isochronous frame (burst), requires --isochronous
-
--isochronous[=fps:mean,stdev]
- send isochronous traffic with frequency frames per second and load defined
by mean and standard deviation using a log normal distribution, defaults
to 60:20m,0
- -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)
- --tx-sync
n
- set the tx-sync interval to n (units of seconds) for synchronized
packet writes
- -B, --bind
ip | ip:port | ipv6 -V | [ipv6]:port
-V
- bind src ip addr and optional port as the source of traffic (see
notes)
- -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
- -S, --tos
- set the socket's IP_TOS (byte) field
- -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)
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
- The -b option supports variable
offered loads through the <mean>,<standard deviation> format,
e.g. -b 100m,10m on the client. The distribution used is log normal. Similar
for the isochronous option.
- The -e or --enhanced latency
output on the UDP servers assumes the clients' and servers' system clocks
are synchronized. Network Time Protocol (NTP) or Precision Time Protocol
(PTP) are commonly used for this. The reference clock(s) or oscillator's
error will also affect the accuracy of UDP latency measurements.
- The -B option affects the
bind() system call. This is typically used to bind to a particular IP
address. Only packets destined to that IP address will be received while any
transmitted packets will carry that IP address as their source. The bind()
does not control anything about the routing of transmitted packets. So, for
example, if the IP address of eth0 is used for -B and the routing table for
the destination IP address (per -c) resolves the output interface to be
eth1, then the host will send the packet out device eth1 with the source IP
address of eth0. To affect the physical output interface (e.g. dual homed
systems) the host's routing table(s) need to be configured, e.g. configure
policy routing per each -B source address.
This section needs to be filled in.
See https://sourceforge.net/p/iperf2/tickets/
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>
http://sourceforge.net/projects/iperf2/