FTP 220 Service Ready vs 451 Local Error
FTP 220 (Service Ready) is a 2xx Positive Completion response, while 451 (Local Error) is a 4xx Transient Negative response. 220 indicates that service ready for new user. This is the greeting message sent by the FTP server when a client first connects. In contrast, 451 means that requested action aborted: local error in processing. The server encountered an unexpected error while trying to complete the command.
설명
Service ready for new user. This is the greeting message sent by the FTP server when a client first connects.
이 코드를 보게 되는 경우
Immediately upon connecting to an FTP server. This is the welcome banner confirming the server is accepting connections.
해결 방법
No fix needed — the server is ready. Proceed with USER and PASS commands to authenticate.
설명
Requested action aborted: local error in processing. The server encountered an unexpected error while trying to complete the command.
이 코드를 보게 되는 경우
When the server has an internal issue like a disk I/O error, memory shortage, or filesystem problem during command processing.
해결 방법
Retry the command. If the error persists, contact the server administrator to check disk health, available memory, and server logs.
주요 차이점
220 is a 2xx Positive Completion response, while 451 is a 4xx Transient Negative response.
FTP 220: Service ready for new user. This is the greeting message sent by the FTP server when a client first connects.
FTP 451: Requested action aborted: local error in processing. The server encountered an unexpected error while trying to complete the command.
You encounter 220 when immediately upon connecting to an FTP server. This is the welcome banner confirming the server is accepting connections.
You encounter 451 when when the server has an internal issue like a disk I/O error, memory shortage, or filesystem problem during command processing.
언제 어떤 것을 사용할지
For 220 (Service Ready): No fix needed — the server is ready. Proceed with USER and PASS commands to authenticate. For 451 (Local Error): Retry the command. If the error persists, contact the server administrator to check disk health, available memory, and server logs.