FTP 110 Restart Marker Reply vs 225 Data Connection Open
FTP 110 (Restart Marker Reply) is a 1xx Positive Preliminary response, while 225 (Data Connection Open) is a 2xx Positive Completion response. 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. In contrast, 225 means that data connection open; no transfer in progress. The data channel is established and ready but no file transfer has started yet.
Description
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.
When You See It
During a resumed file transfer when the server confirms the restart position in the data stream.
How to Fix
No fix needed — this is a normal response during transfer recovery. If restarts keep failing, verify the marker format matches what your client expects.
Description
Data connection open; no transfer in progress. The data channel is established and ready but no file transfer has started yet.
When You See It
When the data connection is established but idle, waiting for a transfer command to begin sending or receiving data.
How to Fix
No fix needed — the data connection is ready. Issue a RETR, STOR, or LIST command to start using it.
Key Differences
110 is a 1xx Positive Preliminary response, while 225 is a 2xx Positive Completion response.
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 225: Data connection open; no transfer in progress. The data channel is established and ready but no file transfer has started yet.
You encounter 110 when during a resumed file transfer when the server confirms the restart position in the data stream.
You encounter 225 when when the data connection is established but idle, waiting for a transfer command to begin sending or receiving data.
When to Use Which
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 225 (Data Connection Open): No fix needed — the data connection is ready. Issue a RETR, STOR, or LIST command to start using it.