FTP 220 Service Ready vs 502 Command Not Implemented
FTP 220 (Service Ready) is a 2xx Positive Completion response, while 502 (Command Not Implemented) is a 5xx Permanent Negative response. 220 indicates that service ready for new user. This is the greeting message sent by the FTP server when a client first connects. In contrast, 502 means that command not implemented. The server recognizes the command but does not support it in its current configuration.
説明
Service ready for new user. This is the greeting message sent by the FTP server when a client first connects.
このコードが表示される場合
Immediately upon connecting to an FTP server. This is the welcome banner confirming the server is accepting connections.
解決方法
No fix needed — the server is ready. Proceed with USER and PASS commands to authenticate.
説明
Command not implemented. The server recognizes the command but does not support it in its current configuration.
このコードが表示される場合
When you use a valid FTP command that this particular server has not implemented, such as SITE or SMNT.
解決方法
Use an alternative command or approach. Check the server's FEAT response or HELP output to see which commands are actually supported.
主な違い
220 is a 2xx Positive Completion response, while 502 is a 5xx Permanent Negative response.
FTP 220: Service ready for new user. This is the greeting message sent by the FTP server when a client first connects.
FTP 502: Command not implemented. The server recognizes the command but does not support it in its current configuration.
You encounter 220 when immediately upon connecting to an FTP server. This is the welcome banner confirming the server is accepting connections.
You encounter 502 when when you use a valid FTP command that this particular server has not implemented, such as SITE or SMNT.
どちらをいつ使うか
For 220 (Service Ready): No fix needed — the server is ready. Proceed with USER and PASS commands to authenticate. For 502 (Command Not Implemented): Use an alternative command or approach. Check the server's FEAT response or HELP output to see which commands are actually supported.