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.
Mô tả
The data connection is already open and the transfer is beginning. No need to open a new data connection.
Khi bạn thấy mã này
When the server reuses an existing data connection for a file transfer instead of opening a new one.
Cách khắc phục
No fix needed — the transfer is starting immediately. Your client should begin reading or writing data on the existing connection.
Mô tả
Service closing control connection. The server is logging out and closing the session in response to a QUIT command.
Khi bạn thấy mã này
After issuing the QUIT command to gracefully disconnect from the FTP server.
Cách khắc phục
No fix needed — the session has ended normally. Reconnect with a new session if needed.
Sự khác biệt chính
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.
Khi nào dùng cái nào
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.