== iperf 3.5 2018-03-02 ==

* Notable user-visible changes

* iperf3 no longer counts data received after the end of a test in

the bytecounts. This fixes a bug that could, under some

conditions, artificially inflate the transfer size and measured

bitrate. This bug was most noticeable on reverse direction

transfers on short tests over high-latency or buffer-bloated

paths. Many thanks to @FuzzyStatic for providing access to a test

environment for diagnosing this issue (#692).

* Notable developer-visible changes

== iperf 3.4 2018-02-14 ==

* Notable user-visible changes

* The -A (set processor affinity) command-line flag is now supported

on Windows (#665).

* iperf3 now builds on systems lacking a daemon(3) library call

(#369).

* A bug in time skew checking under authentication was fixed (#674).

* IPv6 flow labels now work correctly with multiple parallel streams

(#694).

* The client no longer closes its control connection before sending

end-of-test statistics to the server (#677). This fixes a

regression introduced in iperf-3.2.

* Sending output to stdout now makes errors go to stderr, as per

UNIX convention (#695).

* A server side crash in verbose output with a client running

multiple parallel connections has been fixed (#686).

* The --cport option can now be specified without the --bind option.

Using the --cport option on Linux can eliminate a problem with

ephemeral port number allocation that can make multi-stream iperf3

tests perform very poorly on LAGG links. Also, the --cport option

now works on SCTP tests (#697).

* Notable developer-visible changes

* iperf3 now builds on (some) macOS systems older than 10.7 (#607).

* Some unused code and header inclusions were eliminated (#667,

#668). Also some code was cleaned up to eliminate (or at least

reduce) compiler warnings (#664, #671).

== iperf 3.3 2017-10-31 ==

* Notable user-visible changes

* iperf3 can now be built --without-openssl on systems where OpenSSL

is present (#624, #633).

* A bug with printing very large numbers has been fixed (#642).

* A bug where the server would, under certain circumstances, halt a

test after exactly fifteen seconds has been fixed (#645).

* The --tos parameter is no longer "sticky" between tests when doing

--reverse tests (#639).

* The authentication token on the server is properly reset between

tests (#650).

* A bug that could cause iperf3 to overwrite the PID file of an

already-existing iperf3 process has been fixed (#623).

* iperf3 will now ignore nonsensical TCP MSS values (from the TCP

control connection) when trying to determine a reasonable block

size for UDP tests. This condition primarily affected users on

Windows, but potentially improves robustness for all

platforms. (#659)

* Notable developer-visible changes

== iperf 3.2 2017-06-26 ==

* User-visible changes

* Authentication via a username/password mechanism, coupled with a

public-key pair, is now an optional way of limiting access to an

iperf3 server (#517).

* Ending statistics are less ambiguous for UDP and also now use

correct test durations for all protocols (#560, #238). Many fixes

have been made in statistics printing code, generally for

human-readable output (#562, #575, #252, #443, #236).

* Several problems with the -F/--file options have been fixed.

Documentation has been improved to note some ways in which this

feature might not behave as expected (#588).

* iperf3 now uses the correct "bitrate" phraseology rather than

"bandwidth" when describing measurement results. The --bandwidth

option has been renamed --bitrate, although --bandwidth is still

accepted for backwards compatibility (#583).

* Application-level bandwidth pacing (--bitrate option) is now

checked every millisecond by default, instead of of every tenth of

a second, to provide smoother traffic behavior when using

application pacing (#460). The pacing can be tuned via the use of

the --pacing-timer option (#563).

* A new --dscp option allows specifying the DSCP value to be used

for outgoing packets (#508). The TOS byte value is now printed in

the JSON output (#226).

* Congestion window data on FreeBSD is now computed correctly (#465,

#475, #338).

* The T/t suffixes for terabytes/terabits are now accepted for

quantities where suffixes are supported, such as --bandwidth

(#402).

* Sanity checks for UDP send sizes have been added (#390), and

existing checks on the --window option have been improved (#557).

* The TCP rttvar value is now available in the JSON output (#534), as are

the socket buffer sizes (#558).

* Error handling and documentation have been improved for the

-f/--format options (#568).

* A new --connect-timeout option on the client allows specifying a

length of time that the client will attempt to connect to the

server, in milliseconds (#216).

* The hostname and current timestamp are no longer used in the

cookie used to associate the client and server. Instead, random

data is used. Note that iperf3 now requires the /dev/urandom

device (#582).

* Prior versions of iperf3 doing UDP tests used to overcount packet

losses in the presence of packet reordering. This has been

(partially) fixed by try to not count the sequence number gaps

resulting from out-of-order packets as actual losses (#457).

* iperf3 no longer prints results from very small intervals (10% of

the statistics reporting interval) at the end of the test run if

they contain no data. This can happen due to timing difference or

network queueing on the path between the client and server. This

is primarily a cosmetic change to prevent these fairly meaningless

intervals from showing up in the output (#278).

* Compatiblity note: Users running iperf3 3.2 or newer from the

bwctl utility will need to obtain version 1.6.3 or newer of bwctl.

Note that bwctl, a component of the perfSONAR toolkit, has been

deprecated in favor of pScheduler since the release of perfSONAR

4.0.

* Developer-visible changes

* Various warnings and build fixes (#551, #564, #518, #597).

* Some improvements have been made for increased compatibility on

IRIX (#368) and with C++ (#587).

* cJSON has been updated to 1.5.2 (#573), bringing in a number of

bugfixes.

* Some dead code has been removed.

== iperf 3.1.7 2017-03-06 ==

iperf 3.1.7 is functionally identical to iperf 3.1.6. Its only

changes consist of updated documentation files and text in the RPM

spec file.

== iperf 3.1.6 2017-02-02 ==

The release notes for iperf 3.1.6 describe changes, including bug

fixes and new functionality, made since iperf 3.1.5.

* User-visible changes

* Specifying --fq-rate or --no-fq-socket-pacing on a system where

these options are not supported now generate an error instead of a

warning. This change makes diagnosing issues related to pacing

more apparent.

* Fixed a bug where two recently-added diagnostic messages spammed

the JSON output on UDP tests.

== iperf 3.1.5 2017-01-12 ==

The release notes for iperf 3.1.5 describe changes, including bug

fixes and new functionality, made since iperf 3.1.4.

Compatibility note: Fair-queueing is now specified differently in

iperf 3.1.5 than in prior versions (which include 3.1.3 and 3.1.4).

Compatibility note: UDP tests may yield different results from all

prior versions of iperf3 (through 3.1.4) due to the new default UDP

sending size.

* User-visible changes

* The fair-queueing per-socket based pacing available on recent

Linux systems has been reimplemented with a different user

interface (#325, #467, #488). The --bandwidth command-line flag

now controls only the application-level pacing, as was the case in

iperf 3.1.2 and all earlier versions. Fair-queueing per-socket

based pacing is now controlled via a new --fq-rate command-line

flag. Note that TCP and UDP tests may use --bandwidth, --fq-rate,

both flags, or neither flag. SCTP tests currently support

--bandwidth only. The --no-fq-socket-pacing flag, which was

introduced in iperf 3.1.3, has now been deprecated, and is

equivalent to --fq-rate=0. iperf3 now reacts more gracefully if

--no-fq-socket-pacing or --fq-rate are specified on platforms that

don't support these options.

For UDP tests, note that the default --bandwidth is 1 Mbps. Using

the fair-queueing-based pacing will probably require explicitly

setting both --bandwidth and --fq-rate, preferably to the same

value. (While setting different values for --bandwidth and

--fq-rate can certainly be done, the results can range from

entertaining to perplexing.)

* iperf3 now chooses a more sane default UDP send size (#496, #498).

The former default (8KB) caused IP packet fragmentation on paths

having smaller MTUs (including any Ethernet network not configured

for jumbo frames). This could have effects ranging from increased

burstiness, to packet loss, to complete failure of the test.

iperf3 now attempts to use the MSS of the control connection to

determine a default UDP send size if no sending length was

explicitly specified with --length.

* Several checks are now made when setting the socket buffer sizes

with the -w option, to verify that the settings have been applied

correctly. The results of these checks can been seen when the

--debug flag is specified. (#356)

* A --forceflush flag has been added to flush the output stream

after every statistics reporting interval.

* Developer-visible changes

* A systemd service file has been added (#340, #430).

== iperf 3.1.4 2016-10-31 ==

The release notes for iperf 3.1.4 describe changes, including bug

fixes and new functionality, made since iperf 3.1.3.

* User-visible changes

* On systems that support setting the congestion control algorithm,

iperf3 now keeps track of the congestion control algorithm and

print it in the JSON output in the members sender_tcp_congestion

and receiver_tcp_congestion (issue #461). A few bugs (probably

not user-visible) with setting the congestion control algorithm

were also fixed.

* Developer-visible changes

* Fixed a buffer overflow in the cJSON library (issue #466). It is

not believed that this bug created any security vulnerabilities in

the context of iperf3.

* Travis CI builds are now enabled on this codeline (pull request #424).

* Various bug fixes (issue #459, pull request #429, issue #388).

== iperf 3.1.3 2016-06-08 ==

The release notes for iperf 3.1.3 describe changes, including bug

fixes and new functionality, made since iperf 3.1.2.

* Security

* Fixed a buffer overflow / heap corruption issue that could occur

if a malformed JSON string was passed on the control channel. In

theory, this vulnerability could be leveraged to create a heap

exploit. This issue, present in the cJSON library, was already

fixed upstream, so was addressed in iperf3 by importing a newer

version of cJSON (plus local ESnet modifications). Discovered and

reported by Dave McDaniel, Cisco Talos. Cross-references:

TALOS-CAN-0164, ESNET-SECADV-2016-0001, CVE-2016-4303.

* User-visible changes

* On supported platforms (recent Linux), iperf3 can use

fair-queueing-based per-socket pacing instead of its own

application-level pacing for the --bandwidth option.

Application-level pacing can be forced with the

-no-fq-socket-pacing flag.

* A bug that could show negative loss counters with --udp and --omit

has been fixed (issue #412, pull request #414).

* Error handling has been made slightly more robust. Also, the

iperf3 server will no longer exit after five consecutive errors,

but will only exit for certain types of errors that prevent it

from participating in any tests at all.

* Developer-visible changes

* Fixed the build on FreeBSD 11-CURRENT (issue #413).

* Fixed various coding errors (issue #423, issue #425).

== iperf 3.1.2 2016-02-01 ==

The release notes for iperf 3.1.2 describe changes, including bug

fixes and new functionality, made since iperf 3.1.1.

* User-visible changes

* Fixed a bug that caused nan values to be emitted (incorrectly)

into JSON, particularly at the end of UDP tests (issue #278).

* Fixed a bug that caused the wrong value to be printed for

out-of-order UDP packets (issue #329).

* Added a contrib/ directory containing a few submitted graphing

scripts.

* Developer-visible changes

== iperf 3.1.1 2015-11-19 ==

The release notes for iperf 3.1.1 describe changes and new

functionality in iperf 3.1.1, but not present in 3.1.

* User-visible changes

* Some markup fixes have been made in the manpages for Debian

compatibility (issue #291).

* A bug where the -T title option was not being output correctly

in JSON output has been fixed (issue #292).

* Argument handling for some command-line options has been improved

(issue #316).

* Developer-visible changes

* A regression with C++ compatibility in one of the iperf header

files has been fixed (issue #323).

== iperf 3.1 2015-10-16 ==

The release notes for iperf 3.1 describe changes and new

functionality in iperf 3.1, but not present in 3.0.11 or any earlier

3.0.x release.

* Selected user-visible changes

* SCTP support has been added (with the --sctp flag), on Linux,

FreeBSD, and Solaris (issue #131).

* Setting CPU affinity now works on FreeBSD.

* Selection of TCP congestion now works on FreeBSD, and is now

called --congestion (the old --linux-congestion option works

but is now deprecated).

* A new -I option for the server causes it to write a PID file,

mostly useful for daemon mode (issue #120).

* A --logfile argument can now force all output to go to a file,

rather than to a file. This is especially useful when running an

iperf3 server in daemon mode (issue #119).

* Various compatibility fixes for Android (issue #184, issue #185),

iOS (issue #288), NetBSD (issue #248), Solaris (issue #175, issue

#178, issue #180, issue #211), vxWorks (issue #268).

* A --udp-counters-64bit flag has been added to support very

long-running UDP tests, which could cause a counter to overflow

(issue #191).

* A --cport option to specify the client-side port has been added

(issue #207, issue #209, issue #239).

* Some calculation errors with the -O feature have been fixed (issue

#236).

* A potential crash in the iperf3 server has been fixed (issue #257,

issue #258).

* Many miscellaneous bug fixes.

* Selected developer-visible changes

* Consumers of libiperf can now get the JSON output for a

just-completed test (issue #147).

* Detection of various optional features has been improved to check

for the presence or absence of platform functionality, not the name

of platforms.

* Out-of-tree builds now work (issue #265).

== iperf 3.0.11 2015-01-09 ==

* User-visible changes

* Added -1 / --one-off flag, which causes the iperf3 server to

process one client connection and then exit. Intended primarily

for bwctl integration (issue #230).

* Added various minor bug fixes (issues #231, #232, #233).

* Added 30-second timeout for UDP tests if unable to establish UDP

connectivity between sender and receiver (issue #222).

== iperf 3.0.10 2014-12-16 ==

* User-visible changes

* Fixed the build on MacOS X Yosemite (issue #213).

* UDP tests now honor the -w option for setting the socket buffer

sizes (issue #219).

* Developer-visible changes

* Added an RPM spec file plus functionality to fill in the version

number.

* Fixed potential filename collision with a system header (issue

#203).

== iperf 3.0.9 2014-10-14 ==

* User-visible changes

* Fixed a series of problems that came from attempting a UDP test

with a pathologically large block size. This put the server into

an odd state where it could not accept new client connections.

This in turn caused subsequent client connections to crash when

interrupted (issue #212).

* Developer-visible changes

* None.

== iperf 3.0.8 2014-09-30 ==

* User-visible changes

* Updated license and copyright verbage to confirm to LBNL Tech

Transfer requirements. No substantive changes; license remains

the 3-clause BSD license.

* Developer-visible changes

* None.

== iperf 3.0.7 2014-08-28 ==

* User-visible changes

* A server bug where new connections from clients could disrupt

running tests has been fixed (issue #202).

* Rates now consistently use 1000-based prefixes (K, M, G), where

sizes of objects now consistently use 1024-based prefixes (issue #173).

* UDP tests with unlimited bandwidth are now supported (issue #170).

* An interaction between the -w and -B options, which kept them from

working when used together, has been fixed (issue #193).

* Developer-visible changes

== iperf 3.0.6 2014-07-28 ==

* User-visible changes

* Several bugs that kept the -B option from working in various

circumstances have been fixed (issue #193).

* Various compatibility fixes for OpenBSD (issue #196) and

Solaris (issue #177).

* Developer-visible changes

* The {get,set}_test_bind_address API calls have been added to

expose the -B functionality to API consumers (issue #197).

== iperf 3.0.5 2014-06-16 ==

* User-visible changes

* Erroneous output when doing --json output has been fixed (this

problem was caused by an attempt to fix issue #158).

* The maximum test running time has been increased from one hour to

one day (issue #166).

* Project documentation has been moved to GitHub Pages at this URL:

http://software.es.net/iperf/.

* A bug that caused CPU time to be computed incorrectly on FreeBSD

has been fixed.

* A timing issue which caused measurement intervals to be wrong

with TCP tests on lossy networks has been fixed (issue #125).

* Newer versions of autoconf / automake / libtool are now used by

default (issue #161).

* JSON output now indicates whether the test was run in --reverse

mode (issue #167).

* It is now possible to get (most of) the server-side output at

the client by using the --get-server-output flag (issue #160).

* Developer-visible changes

* automake/autoconf/libtool have been updated to more recent

versions. AM_MAINTAINER_MODE is now used to avoid requiring these

tools at build-time.

== iperf 3.0.4 was not released ==

== iperf 3.0.3 2014-03-26 ==

* User-visible changes

* Due to several oversights, the source code archive for iperf 3.0.2

was distributed as an uncompressed tarball, despite having an

extension (".tar.gz") that indicated it was compressed. The

release generation procedure has been changed to avoid this

problem going forward.

* Summary structures in the JSON output are now included, even if

there is only one stream. This change makes consuming the JSON

output easier and more consistent (issue #151).

* A possible buffer overflow in iperf_error.c has been fixed (issue

#155).

* Developer-visible changes

* Example programs now build correctly, after having been broken in

the 3.0.2 release (issue #152).

== iperf 3.0.2 2014-03-10 ==

* User-visible changes

* The iperf3 project has been moved to GitHub, and various URLs in

documentation files have been changed to point there.

* iperf3 now builds on Linux systems that do not support

TCP_CONGESTION. Most notably this allows iperf3 to work on CentOS

5.

* An abort on MacOS 10.9 has been fixed (issue #135).

* Added -I flag for the server to write a PID file, mostly useful for

daemon mode (issue #120).

* A bug that could break some TCP tests on FreeBSD has been fixed.

* TCP snd_cwnd output is now printed by default on Linux (issue #99).

* In JSON output, the --title string no longer has a colon and two

spaces appended (issue #139).

* A buffer for holding formatted numeric values is now

properly-sized so that output is not truncated (issue #142).

* Developer-visible changes

* Some memory leaks have been fixed.

* A -d flag enables debugging output.

* A .gitignore file has been added.

* libtoolize is now invoked correctly from the bootstrap.sh script.

* The test unit format can now be set from the API (issue #144).

* libiperf is now built as both shared and static libraries.

* In the JSON output, the "connection" structures are now stored as

an array in the "start" block, instead of overwriting each other.

While technically an incompatible API change, the former behavior

generated unusable JSON.

== iperf 3.0.1 2014-01-10 ==

* Added the following new flags

-D, --daemon run server as a daemon

-L, --flowlabel set IPv6 flow label (Linux only)

-C, --linux-congestion set congestion control algorithm (Linux only)

-k, --blockcount #[KMG] number of blocks (packets) to transmit

(instead of -t or -n)

* Bug fixes

== iperf 3.0-RC5 2013-11-15 ==

* Added the following new flags

-F, --file name xmit/recv the specified file

-A, --affinity n/n,m set CPU affinity (Linux only)

-J, --json output in JSON format

-Z, --zerocopy use a 'zero copy' method of sending data

-O, --omit N omit the first n seconds

-T, --title str prefix every output line with this string

* more useful information in 'verbose' mode

* Many bug fixes

== iperf 3.0b4 2010-08-02 ==

* Added support for binding to a specific interface (-B)

* Added support for IPv6 mode (-6)

* Setting TCP window size (-w) is now supported

* Updates to iperf_error

* Added new errors

* Should generate more relavent messages

* Stream list now managed by queue.h macros

* Test structures are now kept intact after a test is run (for API users)

* Improved interval timer granularity

* Support for decimal values

* Many bug fixes

== iperf 3.0b3 2010-07-23 ==

* Better error handling

* All errors now handled with iperf_error()

* All functions that can return errors return NULL or -1 on error and set i_errno appropriately

* Iperf API intruduced

* Support for adding new protocols

* Added support for callback functions

* on_connect - executes after a connection is made to the server

* on_new_stream - executes after a new stream is created

* on_test_start - executes right before the test begins

* on_test_finish - executes after the test is finished

* Added early support for verbose mode (-V)

== iperf 3.0b2 2010-07-15 ==

* UDP mode now supported

* Support for setting bandwidth (-b)

* Parallel UDP stream support

* Reverse mode UDP support

* Support for setting TCP_NODELAY (-N), disabling Nagle's Algorithm

* Support for setting TCP MSS (-M)

* Note: This feature is still in development. It is still very buggy.

== iperf 3.0b1 2010-07-08 ==

* TCP control socket now manages messages between client and server

* Dynamic server (gets test parameters from client)

* Server can now set test options dynamically without having to restart.

* Currently supported options: -l, -t, -n, -P, -R

* Future options: -u, -b, -w, -M, -N, -I, -T, -Z, -6

* Results exchange

* Client can now see server results (and vice versa)

* Reverse mode (-R)

* Server sends, client receives