FTP 125 Data Connection Open vs 229 Entering Extended Passive Mode
FTP 125 (Data Connection Open) is a 1xx Positive Preliminary response, while 229 (Entering Extended Passive Mode) 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, 229 means that entering Extended Passive Mode. The server provides only a port number for the data connection, using the same IP as the control connection. Works with both IPv4 and IPv6.
설명
The data connection is already open and the transfer is beginning. No need to open a new data connection.
이 코드를 보게 되는 경우
When the server reuses an existing data connection for a file transfer instead of opening a new one.
해결 방법
No fix needed — the transfer is starting immediately. Your client should begin reading or writing data on the existing connection.
설명
Entering Extended Passive Mode. The server provides only a port number for the data connection, using the same IP as the control connection. Works with both IPv4 and IPv6.
이 코드를 보게 되는 경우
After issuing the EPSV command. The server responds with a port number in the format (|||port|) for the client to connect to.
해결 방법
No fix needed — connect to the server's control IP on the provided port. If it fails, try falling back to PASV (227) or check firewall rules.
주요 차이점
125 is a 1xx Positive Preliminary response, while 229 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 229: Entering Extended Passive Mode. The server provides only a port number for the data connection, using the same IP as the control connection. Works with both IPv4 and IPv6.
You encounter 125 when when the server reuses an existing data connection for a file transfer instead of opening a new one.
You encounter 229 when after issuing the EPSV command. The server responds with a port number in the format (|||port|) for the client to connect to.
언제 어떤 것을 사용할지
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 229 (Entering Extended Passive Mode): No fix needed — connect to the server's control IP on the provided port. If it fails, try falling back to PASV (227) or check firewall rules.