FTP 125 Data Connection Open vs 220 Service Ready
FTP 125 (Data Connection Open) is a 1xx Positive Preliminary response, while 220 (Service Ready) 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, 220 means that service ready for new user. This is the greeting message sent by the FTP server when a client first connects.
Descripción
The data connection is already open and the transfer is beginning. No need to open a new data connection.
Cuándo lo verás
When the server reuses an existing data connection for a file transfer instead of opening a new one.
Cómo solucionarlo
No fix needed — the transfer is starting immediately. Your client should begin reading or writing data on the existing connection.
Descripción
Service ready for new user. This is the greeting message sent by the FTP server when a client first connects.
Cuándo lo verás
Immediately upon connecting to an FTP server. This is the welcome banner confirming the server is accepting connections.
Cómo solucionarlo
No fix needed — the server is ready. Proceed with USER and PASS commands to authenticate.
Diferencias clave
125 is a 1xx Positive Preliminary response, while 220 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 220: Service ready for new user. This is the greeting message sent by the FTP server when a client first connects.
You encounter 125 when when the server reuses an existing data connection for a file transfer instead of opening a new one.
You encounter 220 when immediately upon connecting to an FTP server. This is the welcome banner confirming the server is accepting connections.
Cuándo usar cada uno
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 220 (Service Ready): No fix needed — the server is ready. Proceed with USER and PASS commands to authenticate.