FTP

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.

Descrição

The data connection is already open and the transfer is beginning. No need to open a new data connection.

Quando você o vê

When the server reuses an existing data connection for a file transfer instead of opening a new one.

Como corrigir

No fix needed — the transfer is starting immediately. Your client should begin reading or writing data on the existing connection.

Descrição

Service closing control connection. The server is logging out and closing the session in response to a QUIT command.

Quando você o vê

After issuing the QUIT command to gracefully disconnect from the FTP server.

Como corrigir

No fix needed — the session has ended normally. Reconnect with a new session if needed.

Diferenças principais

1.

125 is a 1xx Positive Preliminary response, while 221 is a 2xx Positive Completion response.

2.

FTP 125: The data connection is already open and the transfer is beginning. No need to open a new data connection.

3.

FTP 221: Service closing control connection. The server is logging out and closing the session in response to a QUIT command.

4.

You encounter 125 when when the server reuses an existing data connection for a file transfer instead of opening a new one.

5.

You encounter 221 when after issuing the QUIT command to gracefully disconnect from the FTP server.

Quando usar qual

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.

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