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iperf3 | Cheatsheet

Listening Server

iperf3 -s

Speedtest the listening server

iperf3 -c listening.server.ip

Run iperf3 in a daemon

iperf3 --daemon

Use udp rather then tcp

iperf3 --udp

Time in seconds to transmit

iperf3 --time 10

Number of bytes to transmit (instead of -t)

iperf3 --bytes 10K/M/G

Run test in 10 parallel threads

iperf3 -P 10 -c listening.server.ip

Run iperf3 on a custom port

iperf3 --port 9090

Report speed in prefered format

Kbits, Mbits, Gbits and TBits is available, use uppercase character for specify format, example below

iper3 --format kmgtK/M/G/T

Set seconds between periodic throughput reports

iperf3 --interval 10

Write a pidfile when using iperf3

iperf --pidfile /var/run/

xmit or recvieve the specified file

iperf3 --file foo.bin

Set CPU affinity

iperf3 --affinity n/n,m 

Bind nic interface to use

iperf3 --bind [host.on.ip__OR__interfaceNic]
iperf3 --json

Run iperf3 in verbose mode

iperf3 -V

Force flush output at every interval

Format must be set with srftime(3)

iperf3  --forceflush=format

Run with debug mode enable

  • 1 = lowest
  • 4 = max
iperf3 --debug=[1-4]
iperf3 --version

RSA private key used to decrypt authentication credentials

iperf3 --rsa-private-key-path    

Path to the configuration file containing user credentials

iperf3  --authorized-users-path   

Time skew threshold (in seconds) between the server

iperf3  --time-skew-threshold     

Set the IPv6 flow label (only supported on Linux)

iperf3 --flowlabel N         

Use a 'zero copy' method of sending data

iperf3 --zerocopy