Commands Supported by FtpWebRequest and IIS FTP

FTP 7.5 accepts the following FTP commands.

214-The following commands are recognized (* ==>'s unimplemented).

    ABOR

    ACCT

    ADAT *

    ALLO

    APPE

    AUTH

    CCC

    CDUP

    CWD

    DELE

    ENC *

    EPRT

    EPSV

    FEAT

    HELP

    HOST

    LANG

    LIST

    MDTM

    MIC *

    MKD

    MODE

    NLST

    NOOP

    OPTS

    PASS

    PASV

    PBSZ

    PORT

    PROT

    PWD

    QUIT

    REIN

    REST

    RETR

    RMD

    RNFR

    RNTO

    SITE

    SIZE

    SMNT

    STAT

    STOR

    STOU

    STRU

    SYST

    TYPE

    USER

    XCUP

    XCWD

    XMKD

    XPWD

    XRMD

214 HELP command successful.

FTP shipped for IIS 6 supports a shorter list of commands,

214-The following  commands are recognized(* ==>'s unimplemented).

   ABOR

   ACCT

   ALLO

   APPE

   CDUP

   CWD

   DELE

   FEAT

   HELP

   LIST

   MDTM

   MKD

   MODE

   NLST

   NOOP

   OPTS

   PASS

   PASV

   PORT

   PWD

   QUIT

   REIN

   REST

   RETR

   RMD

   RNFR

   RNTO

   SITE

   SIZE

   SMNT

   STAT

   STOR

   STOU

   STRU

   SYST

   TYPE

   USER

   XCUP

   XCWD

   XMKD

   XPWD

   XRMD

214  HELP command successful.

Client Side Commands

FtpWebRequest.Method accepts the following commands based on WebRequestMethods.Ftp documentation.

RETR  

NLST  

LIST  

STOR  

STOU  

APPE  

DELE  

MDTM  

SIZE  

RENAME

MKD   

RMD   

PWD   

(in fact if you use FtpWebRequest/FtpWebResponse to develop an FTP application, you will see other commands from the conversation. That’s because they are embedded in the underlying code).

How To Check Which Command Supported By Server

To see what commands are supported by an FTP server, you can

1. Open a command prompt.
2. Type “ftp server_name” to launch ftp utility shipped with Windows.
3. Log in by providing user name and password.
4. Type “remotehelp” in ftp context.

Actually when we use remotehelp here, ftp utility translates that to a HELP command and send to the server.

You can try to use “literal HELP” in ftp context. Of course, the same information is printed out.

FTPS Support

FTP 7.5 introduces full support to FTP over SSL (FTPS). However, FtpWebRequest class available in .NET Framework does not (though it covers some scenarios).

If you need to develop a full FTPS capable client software with .NET, I suggest you visit this open source project.