iperf-3.20

[swlars]

iperf-3.20 2025-11-14

NOTE: iperf-3.20 incorporates all of the changes in prior iperf3
releases, including iperf-3.19.1.

• Notable user-visible changes

  • Millisecond-resolution representations have been added to JSON
    timestamps. (PR json: add UNIX timestamp in milliseconds #1846)

  • The reorder_seen metric, where available, is now available in
    the JSON output. (PR Report number of reorder_seen #1278)

  • A division by zero error has been fixed. (PR src: Fix division by zero in UDP bandwidth calculation in iperf_api.c #1906)

  • Some command-line options were not properly restricted to the
    client or server; this problem has been fixed. (iperf3.18/3.19 udp long time test , lost packets in server report not right #1892 / PR Allow setting options only for client or server #1894)

  • The combination of --udp and --file is now explicitly
    disallowed. (PR Fix for 3 minor issues (unrelated to each other) #1909)

  • It is now possible to get both the full JSON result object as
    well as streaming intermediate JSON result objects. This
    functionality is enabled by using the new --json-stream-full
    command-line flag, in addition to the existing --json-stream
    flag (PR Add Ability To Get Full JSON Result Object With Streams Enabled #1903)

  • Sends with --zerocopy are now properly seeded with data
    instead of being all-zeroes. (PR Fix for 3 minor issues (unrelated to each other) #1909)

  • The --time flag is now allowed on the iperf3 server to impose
    a maximum duration on timed tests. (PR Add Time Flag For The Iperf Server Process #1684, PR Improve Server Max Bit Rate Violation Messaging To Client #1931)

  • The --rcv-timeout flag is now ignored for --bidir
    tests. This change prevents premature termination of
    bidirectional tests. (iperf3: error - control socket has closed unexpectedly (iperf 3.17.1 ) on Debian 12.7 #1766 / PR server: ignore rcv-timeout in BIDIRECTIONAL mode #1946)

  • Several errors in the authentication code were uncovered when
    building with OpenSSL 3.5.3 and later versions. These were
    fixed. (iperf-3.19.1 fails tests with openssl-3.5.3 (3.5.2 is fine) #1951 / PR Resolve issue with openssl 3.5.3 encrypt #1956)

  • Various issues in the iperf3 manual page were fixed up. (PR
    RELNOTES: fix Multipath-TCP flag #1887, PR docs: clarify --get-server-output needs the test to complete #1927, PR manpage updates #1936, PR Fix typo in iperf3 documentation #1941, GitHub repo and software.es.net mismatch on supported OSes #1891 / PR docs: We use Ubuntu, not CentOS, for primary Linux development. #1952)

• Notable developer-visible changes

  • A build failure with uClibc has been fixed. (Fix a compilation issue with uClibc due to a missing include file. #1888 / PR iperf 3.19: missing header #1890)

  • It is now possible to use the API to load RSA keys from a file.
    (PR Support Setting RSA Public/Private Keys from File via libiperf API #1889)

  • Some calls to sprintf() were replaced with calls to
    snprintf(). There were no hazards in the code as written, but
    this change might help silence some compiler warnings and
    potentially prevent future vulnerabilities. (PR Replace sprintf() calls in original iperf3 code #1929)

  • Proper error handling has been added to the unit_atoX()
    functions. (PR Add error handling to the unit_atoX() functions #1394)

  • Some memory handling errors in t_auth were fixed. (PR t_auth memory checks #1953)

  • Minor enhancements and fixes to GitHub Actions workflows (PR
    Github Actions Test #1919, PR Update build.yml Fix Checkout @v4 - @v5  #1928, PR fix update yml #1942).

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This discussion was created from the release iperf-3.20.