Question 1

How do I set up an iperf3 server and client for basic bandwidth testing?

Accepted Answer

Run 'iperf3 -s' on the server to start listening, then on the client use 'iperf3 -c <server_ip>' to initiate a test. Adjust flags like -t for duration or -P for parallel streams as needed, with details in the manual page.

Question 2

iperf3 vs iperf2: which should I use for network troubleshooting?

Accepted Answer

iperf3 offers a cleaner codebase, JSON output, and library features but isn't backwards compatible. iperf2 might be better if you need legacy tool integration or broader community scripts, as both are actively developed separately.

Question 3

Does iperf3 support Windows operating systems?

Accepted Answer

iperf3 is not officially supported on Windows; primary development targets Linux, FreeBSD, and macOS. Community ports may exist, but they lack guaranteed stability or updates from the core team.

Question 4

How can I use iperf3 JSON output in a Python script?

Accepted Answer

Use the --json flag during testing to output results in JSON format, then parse the data with Python's json module for automated analysis, such as extracting throughput or loss metrics programmatically.

Question 5

What are the best iperf3 flags for testing high-speed networks?

Accepted Answer

Enable zero-copy mode with -Z for reduced CPU overhead, use -A for CPU affinity to bind processes, and adjust buffer sizes with -w to match network conditions, as recommended in the README for extreme optimizations.

Question 6

Can iperf3 be used for continuous network monitoring?

Accepted Answer

iperf3 is designed for discrete tests, not real-time monitoring. For ongoing assessment, integrate it into cron jobs or scripts with the library API, but it lacks built-in monitoring features like alerting or dashboards.

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