search

esnet / iperf

iperf3: A TCP, UDP, and SCTP network bandwidth measurement tool
Other
6.93k stars 1.28k forks source link

iperf3: error - unable to connect to server: Connection refused #1092

Open SHIN-CHANG-HEE opened 3 years ago

SHIN-CHANG-HEE commented 3 years ago

NOTE: The iperf3 issue tracker is for registering bugs, enhancement requests, or submissions of code. It is not a means for asking questions about building or using iperf3. Those are best directed towards the iperf3 mailing list at iperf-dev@googlegroups.com or question sites such as Stack Overflow (http://www.stackoverflow.com/). A list of frequently-asked questions regarding iperf3 can be found at http://software.es.net/iperf/faq.html.

Context

Please note: iperf3 is supported on Linux, FreeBSD, and macOS. Support may be provided on a best-effort basis to other UNIX-like platforms. We cannot provide support for building and/or running iperf3 on Windows, iOS, or Android.

Please fill out one of the "Bug Report" or "Enhancement Request" sections, as appropriate.

Bug Report

Now I'm running iperf3 on two machine. and Two machines are running windows 10, WSL 2, Ubuntu 20.04. iPerf3 version has same both server and client machine. iperf 3.7

Two machine is possible icmp request and reply without any problem. But when I tried to start iperf3 from client I met this error.

1) iPerf3 Server screen(Server IP is 192.168.200.253) root@SHINCH01-15U560:/usr/bin# iperf3 -s

Server listening on 5201

2) iPerf Client Screen.(Client IP is 192.168.200.251) root@CHANGHEESHIN01-5501I5:/usr/bin# iperf3 -c 192.168.200.253 -i 2 iperf3: error - unable to connect to server: Connection refused

I already shutdown windows firewall and ubuntu firewall with the following command

root@CHANGHEESHIN01-5501I5:/usr/bin# ufw disable Firewall stopped and disabled on system startup root@CHANGHEESHIN01-5501I5:/usr/bin# ufw status Status: inactive

Can I know what is root cause?

Thank you.

bmah888 commented 3 years ago

It looks like you're running iperf3 correctly...at least I do not see any obvious problems. I see that you shut down the firewall system on the client host...did you do this on the server host as well?

This is not an environment that we officially support or have much experience with. The only other things I can think of would be to try switching the roles of the client and server hosts (if possible), or to try running an iperf3 server on one of the hosts and having an iperf3 client do a test to itself. These might give some other information to help solve the problem.

HugeLeaf commented 2 years ago

everything is ok when using nc, but connection error using iperf3 :( when you test a udp port, the same tcp port must be accessible or the connection will fail

zhangyashen commented 2 years ago

Any conclusion on the current issue? I got the same error, nc is working normal , iperf3 connect refused

davidBar-On commented 2 years ago

Maybe try using different server port numbers (--port), in case 5201 and some other ports are blocked for some reason.

hatrd commented 11 months ago

For your information: I have a VMware network with the IP address 192.168.12.1. The network I intend to test also has the IP address 192.168.12.1. This led iperf3 to detect the wrong host (VMware localhost). I resolved the issue by changing the subnet addresses.