How to issue ftp raw commands

Abstract

This article explains how to issue ftp commands using the telnet protocol. This allow access to a lower layer of the protocol useful for troubleshooting or to determine if specific ftp command are implemented on the FTP server.

Procedure

The telnet command can be use to test a FTP server. Note that the plain telnet client itself would be unable to handle the data stream to send or receive files without the usage of a ftp client.

Example

telnet delta.cri.hp.com 21
Trying 16.90.48.75...
Connected to delta.cri.hp.com.
Escape character is '^]'.
220 delta.cri.hp.com FTP server (Revision 3.0 Version wuftpd-2.6.1 Wed Dec 19 08:27:34 GMT 2007) ready.
USER test
331 Password required for test.
PASS testpasswd
230 User root logged in.
PASV
227 Entering Passive Mode (16,90,48,75,20,107)
RETR /var/tmp/rootcrontab4969.bak
...

Reference

• List of FTP commands for the Microsoft command-line FTP client
• FTP Explorer FAQ

Authors

• Alejandro Marin Badilla