windows server 2003 使用filezilla 时，安装好之后，点击“Active”可能会报下面的错
Creating listen socket on port 21...
Failed to create listen socket on port 21 for IPv4
Failed to create listen socket on port 21 for IPv6
Failed to create a listen socket on any of the specified ports. Server is not online!
Creating listen socket on port 21...
Failed to create listen socket on port 21 for IPv4
Failed to create listen socket on port 21 for IPv6
Failed to create a listen socket on any of the specified ports. Server is not online!
Creating listen socket on port 21...
Failed to create listen socket on port 21 for IPv4
Failed to create listen socket on port 21 for IPv6
具体的解决办法：
一般这种情况是因为21 端口被占用，先用这个命令查询一下
复制代码 代码如下:
netstat -abn |findstr 21
检查一下是不是你的iis 自带的ftp开启了，或者安装了什么其他ftp 软件，先停止，再启用filezilla，就可以了。