FTP 110 Restart Marker Reply vs 125 Data Connection Open
Both FTP 110 (Restart Marker Reply) and 125 (Data Connection Open) belong to the 1xx Positive Preliminary category. 110 indicates that the server is sending a restart marker reply. The text is exact and not left to interpretation. This marker is used to indicate the point at which a file transfer should be restarted. Meanwhile, 125 means that the data connection is already open and the transfer is beginning. No need to open a new data connection.
Descripción
The server is sending a restart marker reply. The text is exact and not left to interpretation. This marker is used to indicate the point at which a file transfer should be restarted.
Cuándo lo verás
During a resumed file transfer when the server confirms the restart position in the data stream.
Cómo solucionarlo
No fix needed — this is a normal response during transfer recovery. If restarts keep failing, verify the marker format matches what your client expects.
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.
Diferencias clave
FTP 110: The server is sending a restart marker reply. The text is exact and not left to interpretation. This marker is used to indicate the point at which a file transfer should be restarted.
FTP 125: The data connection is already open and the transfer is beginning. No need to open a new data connection.
You encounter 110 when during a resumed file transfer when the server confirms the restart position in the data stream.
You encounter 125 when when the server reuses an existing data connection for a file transfer instead of opening a new one.
Cuándo usar cada uno
For 110 (Restart Marker Reply): No fix needed — this is a normal response during transfer recovery. If restarts keep failing, verify the marker format matches what your client expects. 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.