FTP 202 Command Superfluous vs 503 Bad Sequence
FTP 202 (Command Superfluous) is a 2xx Positive Completion response, while 503 (Bad Sequence) 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, 503 means that bad sequence of commands. The command is valid but was sent in the wrong order relative to other commands.
Mô tả
The command is not implemented but is recognized as superfluous. The server acknowledges the command but it has no effect.
Khi bạn thấy mã này
When you send a command the server recognizes but considers unnecessary, such as ALLO on a server that does not require pre-allocation.
Cách khắc phục
No fix needed — the server is telling you the command is not necessary. You can safely ignore this response and continue.
Mô tả
Bad sequence of commands. The command is valid but was sent in the wrong order relative to other commands.
Khi bạn thấy mã này
When you skip a required step, like sending PASS before USER, or RNTO without first sending RNFR.
Cách khắc phục
Follow the correct command sequence. Common sequences: USER then PASS for login, RNFR then RNTO for rename, PASV then RETR for transfer.
Sự khác biệt chính
202 is a 2xx Positive Completion response, while 503 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 503: Bad sequence of commands. The command is valid but was sent in the wrong order relative to other commands.
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 503 when when you skip a required step, like sending PASS before USER, or RNTO without first sending RNFR.
Khi nào dùng cái nào
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 503 (Bad Sequence): Follow the correct command sequence. Common sequences: USER then PASS for login, RNFR then RNTO for rename, PASV then RETR for transfer.