FTP连接出现这种情况，什么原因

[10:00:10] [R] SIZE
[10:00:10] [R] MDTM
[10:00:10] [R] REST STREAM
[10:00:10] [R] 211 END
[10:00:10] [R] OPTS UTF8 ON
[10:00:10] [R] 200 OPTS UTF8 command successful - UTF8 encoding now ON.
[10:00:10] [R] PWD
[10:00:10] [R] 257 "/" is current directory.
[10:00:10] [R] CWD /
[10:00:10] [R] 250 CWD command successful.
[10:00:10] [R] PWD
[10:00:10] [R] 257 "/" is current directory.
[10:00:10] [R] PASV
[10:00:10] [R] 227 Entering Passive Mode (172,18,119,71,197,190).
[10:00:10] [R] 正在打开数据连接 IP: 39.108.75.47 端口: 50622
[10:00:14] [R] QUIT
[10:00:14] [R] 已注销: 39.108.75.47 (持续时间: 4 秒)
[10:00:14] [R] 连接已取消