iperf returning “bind failed: cannot assign requested address” in Windows XP and 7

Question

I am trying to set up iperf on an old HP server running Windows XP Professional to test multicast, but whenever I issue the command iperf -s -u -B <ip address>, it returns:

bind failed: Cannot assign requested address

It doesn't matter what I put as the IP address (224.0.0.1, 192.168.150.123, 10.254.1.11 were each tested unsuccessfully), it generates exactly the same error. Using different ports with the "-p" flag also has zero effect (iperf defaults to 5001; I have also tried 50, 99, 5002, 8000, 9000).

However, if I use the server's actual IP address (10.254.1.10), the iperf service starts up without any problems. The symptoms are identical on my Windows 7 x64 laptop.

I have looked online for the past few days and I see many people reporting this problem, but I don't see any applicable solutions (the bind error alone tends to be associated with people writing their own code, and it's association with iperf specifically tends to garner no useful answers), so I would really appreciate any assistance, I am tearing my hair out over this vague Windows error.

I am using the precompiled version of iperf 2.0.5-2-win32, but I at this point I don't mind downloading the source, editing it, and compiling it myself if that's the only way to solve this...I just don't have any C++ experience, so I can't go bug-hunting on my own.

Solution

Try a version built without Cygwin from the download page.

I was having the same problem and with version 2.0.8 (12 jan 2015 Windows 32 bits) worked

Comments

[Liesmith]

Unfortunately, I no longer have either server I was using to test with, so I can't verify this solution with my specific situation. Still, if it worked for you, I'll mark it as the answer for anyone else who runs into this issue in the future.

[Samir]

Version 2.0.8 is one of only a few Iperf binaries with the text "built without Cygwin" in its description on the download page. But I wonder if Cygwin is to blame at all. Because I had the same type of bind error (without using the -u option) with version 2.0.5 and it was resolved with version 2.0.6 which is not stated to be built without Cygwin. In addition, version 2.0.8 resolved the issue as well. So while it may so be that 2.0.8 resolved the issue in this case, it may not have done so for the reason you think it did (being built without Cygwin).