}

	err := fd.pfd.SetsockoptInt(syscall.IPPROTO_TCP, windows.TCP_KEEPCNT, n)
	runtime.KeepAlive(fd)
	return os.NewSyscallError("setsockopt", err)
}

// setKeepAliveIdleAndInterval serves for kernels prior to Windows 10, version 1709.
func setKeepAliveIdleAndInterval(fd *netFD, idle, interval time.Duration) error {
	// WSAIoctl with SIO_KEEPALIVE_VALS control code requires all fields in
	// `tcp_keepalive` struct to be provided.

		}
		if err := setKeepAliveInterval(c.fd, config.Interval); err != nil {
			return &OpError{Op: "set", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
		}
	} else if err := setKeepAliveIdleAndInterval(c.fd, config.Idle, config.Interval); err != nil {
		return &OpError{Op: "set", Net: c.fd.net, Source: c.fd.laddr, Addr: c.fd.raddr, Err: err}
	}
	if err := setKeepAliveCount(c.fd, config.Count); err != nil {