Comment 12 for bug 284377

Has anyone been able to test this on an IPv6 network so we could determine the scope of the cause to help hunting it down?

It does look like an IPv4 issue. Could you boot the kernel with "debug" mode, provoke the error, and then check the end of /var/log/kern.log for any relevant kernel errors (This will help to determine if the kernel is seeing the same thing as the userspace applications) ?