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Note that this documentation is for the deprecated version 1 software image of the WLAN Pi

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 receive traffic) and a client (to generate traffic).

The WLAN Pi has iperf2 and iperf3 servers running upon start-up, these servers are using the default options for each version.

For reference, iperf uses the following ports:

iperf2 - 5001
iperf3 - 5201

Iperf3 is a rewrite of iperf from scratch to create a smaller, simpler code base. Iperf3 is not backwards compatible with iperf2.


To view all iperf options, take a look the manual pages for the software using the following CLI command in your SSH session (hit 'q' to quit the man pages) or use the -h or --help flag for listing of the commands:

man iperf
iperf -h

man iperf3
iperf3 -h


Basic throughput test

(Note that by default, iperf tests using TCP. To use UDP, see later examples.)

iperf -c <server_ip>
iperf3 -c <server_ip>


Displaying data formatted in different units.

The units that in which results are displayed (i.e. Kilobits per sec, Megabits per sec etc.) may be modified using the following command attributes:

iperf -c <server_ip>  -f (b, B, k, K, m, M, g, G, t, T)
iperf3 -c <server_ip>  -f (b, B, k, K, m, M, g, G, t, T)


iperf from server to client (reverse direction test) or bi-directional test

iperf -c <server_ip>  -r -d


iperf3 -c <server_ip>  -R or iperf3 -c <server_ip>  --bidir


iperf using udp

iperf -c <server_ip> -u
iperf3 -c <server_ip> -u



The following references may be useful for further information about iperf:

(Contributed by Ian Stout)

Last update: October 4, 2020