iperf3: error - unable to send control message: Bad file descriptor ...

github.com/esnet/iperf/issues/1233
In my case I had been staring at "bad file descriptor" for some time thinking "but this worked a few moments ago, why won't it work now?". I kept re-trying the commands at each end, without ever realising I had omitted the "3" at the server end.

iperf3: error - unable to send control message: Bad file descriptor ...

github.com/esnet/iperf/issues/1150
iperf3 -c 192.168.189.167 -t 3 -p 5201 -l 16K -f M -P 3 I also have this problem on Arch Linux: iperf 3.9 (cJSON 1.7.13) Linux hostname 5.12.6-arch1-1 #1 SMP PREEMPT Sun, 23 May 2021 00:45:50 +0000 x86_64 Optional features available: CPU affinity setting, IPv6 flow label, TCP congestion algorithm setting, sendfile / zerocopy, socket pacing, authentication However, I have built an AUR git ...

iperf3: error - unable to send control message: Bad file descriptor

community.nxp.com/t5/i-MX-Processors/iperf3-error-unable-to-send-control-message-Bad-file-descriptor/m-p/1419454
A user reports an error when using iperf3 to measure Wi-Fi throughput with i.MX8M Plus EVK. A solution is provided by NXP TechSupport to check and open firewall settings on both client and server.

Why iperf3 Says Bad File Descriptor and What to Check First

www.webnuz.com/article/2026-08-07/Why iperf3 Says Bad File Descriptor and What to Check First     2026-08-07T13:58:00.0000000
Keep the whole line. Bad file descriptor comes from your operating system. It does not identify the operation that failed. The text before it names the iperf3 stage. In this case, iperf3 tried to write to its control socket. The operating system rejected the descriptor passed to that write with EBADF.

iperf3 stop running after 300 sec with error - unable to send control ...

stackoverflow.com/questions/75937817/iperf3-stop-running-after-300-sec-with-error-unable-to-send-control-message
The error said iperf3: error - unable to send control message: Broken pipe I use IPerf3 version 3.9 on ubuntu of windows 10 wsl for client, and the server side is the public domain that I don't have access to.

iperf connection not being made between two server 10Gb cards

www.reddit.com/r/networking/comments/zsc5s6/iperf_connection_not_being_made_between_two/
A user asks why iperf cannot connect between two servers with 10Gb NICs and gets an error message. Other users reply with possible solutions related to IP addresses, ports, and firewall settings.

Re: iperf3: error - unable to send control message: Bad file descriptor

community.nxp.com/t5/i-MX-Processors/iperf3-error-unable-to-send-control-message-Bad-file-descriptor/m-p/1422519?profile.language=ja
Hi, Sorry, I don't have any information about firewall setting. Please let me know how to open firewall on i.MX8M Plus EVK? If possible, also on Ubuntu. Best Regards ...

Unable to send control message: Bad file descriptor #1105

github.com/esnet/iperf/issues/1105
Hrm, first report of using iperf3 on Apple Silicon! The :9991 probably doesn't do what you want, however. Perhaps you mean something like iperf3 -c 192.168.6.17 -p 9991? Works great, Thanks for reply.

[sles 12 sp5] iperf3 error: iperf3: error - unable to send control ...

github.com/esnet/iperf/issues/1786     2024-10-17T00:00:00.0000000
Build iperf3 from master branch. Run iperf3 -s -D on machine A. Run iperf3 -t 30 -c 10.0.0.5 -P 128 on machine B. It is related with the parameter P When the parallel value is 50, it works, when it is 55, it starts to show this failure. ...

iperf3: error - select failed: Bad file descriptor #653 - GitHub

github.com/esnet/iperf/issues/653
iperf-3.1.7 does not contain this bug. iperf-3.2 has this bug. Below I've interleaved the client and server console outputs. Doing a low latency (veth, localhost) iperf on the same system results i...
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