Tools

502 FTP response code

A 502 code may be sent in response to any FTP command that the server does not support. It is a permanent negative reply, which means the client is discouraged from sending the command again since the server will respond with the same reply code. The original FTP specification dictates a minimum implementation for all FTP servers with a list of required commands. Because of this, a 502 reply code should not be sent in response to a required command.

First published date

10/25/2018 7:33 PM

Last published date

6/11/2020 4:34 PM

Overview

This article explains why the 502 FTP response code is sent.

Product section

Serv-U Managed File Transfer & Serv-U FTP Server

Resolution

A 502 code may be sent in response to any FTP command that the server does not support. It is a permanent negative reply, which means the client is discouraged from sending the command again since the server will respond with the same reply code. The original FTP specification dictates a minimum implementation for all FTP servers with a list of required commands. Because of this, a 502 reply code should not be sent in response to a required command.

Example response 

502 Command not implemented

Possible command 

A 502 response code may be sent to any FTP command that the server does not support.