FTP 200 Command OK vs 503 Bad Sequence
FTP 200 (Command OK) is a 2xx Positive Completion response, while 503 (Bad Sequence) is a 5xx Permanent Negative response. 200 indicates that the command has been successfully executed. This is a general acknowledgment that the command was understood and carried out. In contrast, 503 means that bad sequence of commands. The command is valid but was sent in the wrong order relative to other commands.
คำอธิบาย
The command has been successfully executed. This is a general acknowledgment that the command was understood and carried out.
เมื่อคุณพบเห็น
After issuing any command that completes successfully, such as TYPE, MODE, or NOOP.
วิธีแก้ไข
No fix needed — the command succeeded. This is the standard positive response for commands that don't return data.
คำอธิบาย
Bad sequence of commands. The command is valid but was sent in the wrong order relative to other commands.
เมื่อคุณพบเห็น
When you skip a required step, like sending PASS before USER, or RNTO without first sending RNFR.
วิธีแก้ไข
Follow the correct command sequence. Common sequences: USER then PASS for login, RNFR then RNTO for rename, PASV then RETR for transfer.
ความแตกต่างหลัก
200 is a 2xx Positive Completion response, while 503 is a 5xx Permanent Negative response.
FTP 200: The command has been successfully executed. This is a general acknowledgment that the command was understood and carried out.
FTP 503: Bad sequence of commands. The command is valid but was sent in the wrong order relative to other commands.
You encounter 200 when after issuing any command that completes successfully, such as TYPE, MODE, or NOOP.
You encounter 503 when when you skip a required step, like sending PASS before USER, or RNTO without first sending RNFR.
ควรใช้อันไหนเมื่อไร
For 200 (Command OK): No fix needed — the command succeeded. This is the standard positive response for commands that don't return data. 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.