FTP 202 Command Superfluous vs 550 File Unavailable
FTP 202 (Command Superfluous) is a 2xx Positive Completion response, while 550 (File Unavailable) is a 5xx Permanent Negative response. 202 indicates that the command is not implemented but is recognized as superfluous. The server acknowledges the command but it has no effect. In contrast, 550 means that requested action not taken. File unavailable — the file does not exist, the path is wrong, or you do not have permission to access it.
描述
The command is not implemented but is recognized as superfluous. The server acknowledges the command but it has no effect.
何时出现
When you send a command the server recognizes but considers unnecessary, such as ALLO on a server that does not require pre-allocation.
如何修复
No fix needed — the server is telling you the command is not necessary. You can safely ignore this response and continue.
描述
Requested action not taken. File unavailable — the file does not exist, the path is wrong, or you do not have permission to access it.
何时出现
When you try to download, delete, or navigate to a file or directory that does not exist or is restricted by server permissions.
如何修复
Verify the file path and name are correct (FTP paths are case-sensitive on most servers). Check your user permissions with the server administrator.
主要区别
202 is a 2xx Positive Completion response, while 550 is a 5xx Permanent Negative response.
FTP 202: The command is not implemented but is recognized as superfluous. The server acknowledges the command but it has no effect.
FTP 550: Requested action not taken. File unavailable — the file does not exist, the path is wrong, or you do not have permission to access it.
You encounter 202 when when you send a command the server recognizes but considers unnecessary, such as ALLO on a server that does not require pre-allocation.
You encounter 550 when when you try to download, delete, or navigate to a file or directory that does not exist or is restricted by server permissions.
何时使用哪个
For 202 (Command Superfluous): No fix needed — the server is telling you the command is not necessary. You can safely ignore this response and continue. For 550 (File Unavailable): Verify the file path and name are correct (FTP paths are case-sensitive on most servers). Check your user permissions with the server administrator.