FTP 125 Data Connection Open vs 225 Data Connection Open
FTP 125 (Data Connection Open) is a 1xx Positive Preliminary response, while 225 (Data Connection Open) 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, 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 data connection is already open and the transfer is beginning. No need to open a new data connection.
When You See It
When the server reuses an existing data connection for a file transfer instead of opening a new one.
How to Fix
No fix needed — the transfer is starting immediately. Your client should begin reading or writing data on the existing connection.
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
125 is a 1xx Positive Preliminary response, while 225 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 225: Data connection open; no transfer in progress. The data channel is established and ready but no file transfer has started yet.
You encounter 125 when when the server reuses an existing data connection for a file transfer instead of opening a new one.
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 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 225 (Data Connection Open): No fix needed — the data connection is ready. Issue a RETR, STOR, or LIST command to start using it.