search

esnet / iperf

iperf3: A TCP, UDP, and SCTP network bandwidth measurement tool
Other
6.76k stars 1.27k forks source link

windows-Connection timed out error #1338

Open guangjinpan opened 2 years ago

guangjinpan commented 2 years ago

On windows, I can ping a Linux server successfully. However, if I use windows ( iperf version 3.1.3) as a client and the Linux server (iperf 3.7.0) as a server, the error "iperf3: error - unable to connect to server: Connection timed out" appears.

I use the Wireshark for testing, and find the problem is "[TCP Retransmission] [TCP Port numbers reused] 52055 → 5201 ……" image

davidBar-On commented 2 years ago

Wireshark mark the SYN transmissions with "[TCP Port numbers reused]" because it already saw such SYN (the original message), so this is not a problem. See here for more info.

The problem is that for some reason either the server does not receive the packet or its response is lost. It would help to run Wireshark also on the server side to determine this. In any case, it seems that issue is related to a firewall. E.g. port 5201 is blocked on the server side.

(By the way, you can get a newer version of iperf3 for Windows here.)