FTP 212 Directory Status vs 421 Service Not Available
FTP 212 (Directory Status) is a 2xx Positive Completion response, while 421 (Service Not Available) is a 4xx Transient Negative response. 212 indicates that directory status reply. The server provides information about the current directory or a specified directory. 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.
คำอธิบาย
Directory status reply. The server provides information about the current directory or a specified directory.
เมื่อคุณพบเห็น
After issuing the STAT command on a directory, the server returns the directory listing or status information.
วิธีแก้ไข
No fix needed — this is an informational response showing directory contents or status.
คำอธิบาย
Service not available, closing control connection. The server is shutting down or has reached its connection limit and cannot serve this request.
เมื่อคุณพบเห็น
When the FTP server is overloaded, shutting down for maintenance, or has reached its maximum number of concurrent connections.
วิธีแก้ไข
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.
ความแตกต่างหลัก
212 is a 2xx Positive Completion response, while 421 is a 4xx Transient Negative response.
FTP 212: Directory status reply. The server provides information about the current directory or a specified directory.
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 212 when after issuing the STAT command on a directory, the server returns the directory listing or status information.
You encounter 421 when when the FTP server is overloaded, shutting down for maintenance, or has reached its maximum number of concurrent connections.
ควรใช้อันไหนเมื่อไร
For 212 (Directory Status): No fix needed — this is an informational response showing directory contents or status. 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.