FTP 202 Command Superfluous vs 421 Service Not Available
FTP 202 (Command Superfluous) is a 2xx Positive Completion response, while 421 (Service Not Available) is a 4xx Transient 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, 421 means that service not available, closing control connection. The server is shutting down or has reached its connection limit and cannot serve this request.
Descripción
The command is not implemented but is recognized as superfluous. The server acknowledges the command but it has no effect.
Cuándo lo verás
When you send a command the server recognizes but considers unnecessary, such as ALLO on a server that does not require pre-allocation.
Cómo solucionarlo
No fix needed — the server is telling you the command is not necessary. You can safely ignore this response and continue.
Descripción
Service not available, closing control connection. The server is shutting down or has reached its connection limit and cannot serve this request.
Cuándo lo verás
When the FTP server is overloaded, shutting down for maintenance, or has reached its maximum number of concurrent connections.
Cómo solucionarlo
Wait a few minutes and try reconnecting. If persistent, check if the server has a connection limit and whether your IP is being rate-limited.
Diferencias clave
202 is a 2xx Positive Completion response, while 421 is a 4xx Transient 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 421: Service not available, closing control connection. The server is shutting down or has reached its connection limit and cannot serve this request.
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 421 when when the FTP server is overloaded, shutting down for maintenance, or has reached its maximum number of concurrent connections.
Cuándo usar cada uno
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 421 (Service Not Available): Wait a few minutes and try reconnecting. If persistent, check if the server has a connection limit and whether your IP is being rate-limited.