FTP 211 System Status vs 551 Page Type Unknown
FTP 211 (System Status) is a 2xx Positive Completion response, while 551 (Page Type Unknown) is a 5xx Permanent Negative response. 211 indicates that system status or system help reply. The server provides information about its current status or available features. In contrast, 551 means that requested action aborted: page type unknown. The server does not recognize the requested page structure or format.
Descrição
System status or system help reply. The server provides information about its current status or available features.
Quando você o vê
After issuing the STAT command without arguments, the server returns its system status and supported features.
Como corrigir
No fix needed — this is an informational response. Use the information to understand the server's capabilities and current state.
Descrição
Requested action aborted: page type unknown. The server does not recognize the requested page structure or format.
Quando você o vê
When attempting a transfer with a page structure type the server does not support. This is extremely rare in modern FTP usage.
Como corrigir
Switch to stream transfer mode (MODE S) and file structure (STRU F), which are universally supported by all FTP servers.
Diferenças principais
211 is a 2xx Positive Completion response, while 551 is a 5xx Permanent Negative response.
FTP 211: System status or system help reply. The server provides information about its current status or available features.
FTP 551: Requested action aborted: page type unknown. The server does not recognize the requested page structure or format.
You encounter 211 when after issuing the STAT command without arguments, the server returns its system status and supported features.
You encounter 551 when when attempting a transfer with a page structure type the server does not support. This is extremely rare in modern FTP usage.
Quando usar qual
For 211 (System Status): No fix needed — this is an informational response. Use the information to understand the server's capabilities and current state. For 551 (Page Type Unknown): Switch to stream transfer mode (MODE S) and file structure (STRU F), which are universally supported by all FTP servers.