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This cheat sheet provides a quick reference for some common iperf commands and concepts. iperf is a command-line utility used to measure network bandwidth and performance by generating and analyzing network traffic.

iperf Concepts

Server and Client

iperf operates in two modes: server and client.

  • Server Mode: Start iperf in server mode to listen for incoming connections.

    iperf -s
  • Client Mode: Start iperf in client mode to connect to a remote server for testing.

    iperf -c server_ip

TCP and UDP Tests

iperf can perform tests using TCP or UDP protocols.

  • TCP Test (Default): Measure TCP bandwidth.

    iperf -s        # Server
    iperf -c server_ip # Client
  • UDP Test: Measure UDP bandwidth.

    iperf -u -s        # Server
    iperf -u -c server_ip # Client

Test Duration

Specify the test duration using the -t option (in seconds).

  • Run a test for 10 seconds:
    iperf -t 10 -c server_ip

Bandwidth Units

You can control the display units for bandwidth results.

  • Display results in Kbps (Kilobits per second):
    iperf -u -b 1M -c server_ip

Parallel Streams

iperf can use multiple parallel streams for testing.

  • Use 4 parallel streams:
    iperf -P 4 -c server_ip

Reverse Test

Perform a reverse test (server sends data to client).

  • Reverse test with TCP:
    iperf -c server_ip -R

Interval Display

Display intermediate results at specified intervals.

  • Display results every 5 seconds:
    iperf -i 5 -c server_ip

iperf Command-Line

  • Start iperf in server mode:

    iperf -s
  • Start a TCP bandwidth test (client mode):

    iperf -c server_ip
  • Start a UDP bandwidth test (client mode):

    iperf -u -c server_ip
  • Set the test duration to 30 seconds (client mode):

    iperf -t 30 -c server_ip
  • Use 4 parallel streams (client mode):

    iperf -P 4 -c server_ip
  • Display results every 10 seconds (client mode):

    iperf -i 10 -c server_ip


This cheat sheet covers some common iperf commands and concepts. iperf is a powerful tool for measuring network bandwidth and performance, making it useful for network diagnostics, tuning, and testing; refer to the official iperf documentation for more in-depth information and advanced usage.