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503 FTP response code

Updated May 3, 2017


This article provides information on 503 FTP response code.


All Serv-U versions


A 503 response code may be sent in response to any command that requires the successful processing of previous commands first. It is a permanent negative reply, which means the client is discouraged from immediately sending the command again since the server will respond with the same reply code. For example, a file rename requires a successful RNFR command before the RNTO command can be sent. Sending the RNTO command first will result in a 503 response code.

Example response

503 Bad sequence of commands.

Possible commands


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