FTP 202 Command Superfluous vs 331 Username OK, Need Password
FTP 202 (Command Superfluous) is a 2xx Positive Completion response, while 331 (Username OK, Need Password) is a 3xx Positive Intermediate 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, 331 means that user name okay, need password. The server recognized the username and is waiting for the corresponding password to complete authentication.
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
User name okay, need password. The server recognized the username and is waiting for the corresponding password to complete authentication.
何时出现
After sending the USER command with a valid username. The server is prompting for the PASS command.
如何修复
Send the PASS command with the correct password. If you get 530 after PASS, the password is wrong — verify your credentials.
主要区别
202 is a 2xx Positive Completion response, while 331 is a 3xx Positive Intermediate response.
FTP 202: The command is not implemented but is recognized as superfluous. The server acknowledges the command but it has no effect.
FTP 331: User name okay, need password. The server recognized the username and is waiting for the corresponding password to complete authentication.
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 331 when after sending the USER command with a valid username. The server is prompting for the PASS command.
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 331 (Username OK, Need Password): Send the PASS command with the correct password. If you get 530 after PASS, the password is wrong — verify your credentials.