FTP 125 Data Connection Open vs 221 Closing Control Connection
FTP 125 (Data Connection Open) is a 1xx Positive Preliminary response, while 221 (Closing Control Connection) is a 2xx Positive Completion response. 125 indicates that the data connection is already open and the transfer is beginning. No need to open a new data connection. In contrast, 221 means that service closing control connection. The server is logging out and closing the session in response to a QUIT command.
描述
The data connection is already open and the transfer is beginning. No need to open a new data connection.
何时出现
When the server reuses an existing data connection for a file transfer instead of opening a new one.
如何修复
No fix needed — the transfer is starting immediately. Your client should begin reading or writing data on the existing connection.
描述
Service closing control connection. The server is logging out and closing the session in response to a QUIT command.
何时出现
After issuing the QUIT command to gracefully disconnect from the FTP server.
如何修复
No fix needed — the session has ended normally. Reconnect with a new session if needed.
主要区别
125 is a 1xx Positive Preliminary response, while 221 is a 2xx Positive Completion response.
FTP 125: The data connection is already open and the transfer is beginning. No need to open a new data connection.
FTP 221: Service closing control connection. The server is logging out and closing the session in response to a QUIT command.
You encounter 125 when when the server reuses an existing data connection for a file transfer instead of opening a new one.
You encounter 221 when after issuing the QUIT command to gracefully disconnect from the FTP server.
何时使用哪个
For 125 (Data Connection Open): No fix needed — the transfer is starting immediately. Your client should begin reading or writing data on the existing connection. For 221 (Closing Control Connection): No fix needed — the session has ended normally. Reconnect with a new session if needed.