FTP 120 Service Ready Soon vs 421 Service Not Available
FTP 120 (Service Ready Soon) is a 1xx Positive Preliminary response, while 421 (Service Not Available) is a 4xx Transient Negative response. 120 indicates that the service will be ready in a certain number of minutes. The server is not yet available but expects to be shortly. 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.
Description
The service will be ready in a certain number of minutes. The server is not yet available but expects to be shortly.
Quand vous le voyez
When connecting to an FTP server that is starting up or temporarily busy with maintenance tasks.
Comment résoudre
Wait the indicated number of minutes and try connecting again. If the server never becomes ready, contact the server administrator.
Description
Service not available, closing control connection. The server is shutting down or has reached its connection limit and cannot serve this request.
Quand vous le voyez
When the FTP server is overloaded, shutting down for maintenance, or has reached its maximum number of concurrent connections.
Comment résoudre
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.
Différences clés
120 is a 1xx Positive Preliminary response, while 421 is a 4xx Transient Negative response.
FTP 120: The service will be ready in a certain number of minutes. The server is not yet available but expects to be shortly.
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 120 when when connecting to an FTP server that is starting up or temporarily busy with maintenance tasks.
You encounter 421 when when the FTP server is overloaded, shutting down for maintenance, or has reached its maximum number of concurrent connections.
Quand utiliser lequel
For 120 (Service Ready Soon): Wait the indicated number of minutes and try connecting again. If the server never becomes ready, contact the server administrator. 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.