FTP 110 Restart Marker Reply vs 221 Closing Control Connection
FTP 110 (Restart Marker Reply) is a 1xx Positive Preliminary response, while 221 (Closing Control Connection) 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, 221 means that service closing control connection. The server is logging out and closing the session in response to a QUIT command.
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
Service closing control connection. The server is logging out and closing the session in response to a QUIT command.
When You See It
After issuing the QUIT command to gracefully disconnect from the FTP server.
How to Fix
No fix needed — the session has ended normally. Reconnect with a new session if needed.
Key Differences
110 is a 1xx Positive Preliminary response, while 221 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 221: Service closing control connection. The server is logging out and closing the session in response to a QUIT command.
You encounter 110 when during a resumed file transfer when the server confirms the restart position in the data stream.
You encounter 221 when after issuing the QUIT command to gracefully disconnect from the FTP server.
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 221 (Closing Control Connection): No fix needed — the session has ended normally. Reconnect with a new session if needed.