how to use telnet?

DJFuji

Diamond Member
Oct 18, 1999
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google tells me that telnet can't be used to transfer files. I've connected to my web server successfully, but i don't know any other commands to do anything. If file transfer is indeed not possible, why not? Is it because telnet is terminal emulation and can't see your local files?
 

DJFuji

Diamond Member
Oct 18, 1999
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yeah i would except my homework assignment is to explain why telnet can or cannot be used to transfer files.
 

Linflas

Lifer
Jan 30, 2001
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Telnet is a terminal program only. You can use it to ftp but you would be ftp'ing to your shell on the machine you are telneted in to, not your local machine that you are running the client on.
 

GeekDrew

Diamond Member
Jun 7, 2000
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Originally posted by: DJ Fuji
yeah i would except my homework assignment is to explain why telnet can or cannot be used to transfer files.

I'm fairly sure that it cannot. Telnet is indeed terminal emulation only. I have, however, seen file transfer capabilities built into many telnet clients - but they access FTP functions within that client.
 

Eli

Super Moderator | Elite Member
Oct 9, 1999
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If you have a terminal program that supports downloads, you certainly can.

Also, "telnet" is not the terminal emulation program "telnet".

If you mean the Windows program telnet, then you can't transfer files with that.

If you mean the protocol(or whatever) telnet, I'm pretty sure you can.
 

episodic

Lifer
Feb 7, 2004
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Originally posted by: DJ Fuji
yeah i would except my homework assignment is to explain why telnet can or cannot be used to transfer files.

These RFC's should get you started.
http://www.ietf.org


0137 Telnet Protocol - a proposed document. T.C. O'Sullivan.
Apr-30-1971. (Format: TXT=17606 bytes) (Updated by RFC0139) (Status:
UNKNOWN)

0139 Discussion of Telnet Protocol. T.C. O'Sullivan. May-07-1971.
(Format: TXT=26085 bytes) (Updates RFC0137) (Updated by RFC0158)
(Also RFC0393) (Status: UNKNOWN)

0158 Telnet Protocol: A Proposed Document. T.C. O'Sullivan.
May-19-1971. (Not online) (Obsoleted by RFC0495) (Updates RFC0139)
(Updated by RFC0318) (Also RFC0393) (Status: UNKNOWN)

0206 User Telnet - description of an initial implementation. J.E.
White. Aug-09-1971. (Not online) (Status: UNKNOWN)


0414 File Transfer Protocol (FTP) status and further comments. A.K.
Bhushan. Dec-29-1972. (Format: TXT=12845 bytes) (Updates RFC0385)
(Status: UNKNOWN)
 

Descartes

Lifer
Oct 10, 1999
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As it has been stated, telnet itself doesn't facilitate the transfer of files; however, you can use a program like "sz" to send files to yourself from withint a telnet session. Of course, the telnet application needs to support z-modem transfer. I haven't had to use this in many years, but it might be the answer they're looking for.
 

Eli

Super Moderator | Elite Member
Oct 9, 1999
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Haven't any of you ever heard of ZModem?!? :p
 

DJFuji

Diamond Member
Oct 18, 1999
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Originally posted by: Eli
If you have a terminal program that supports downloads, you certainly can.

Also, "telnet" is not the terminal emulation program "telnet".

If you mean the Windows program telnet, then you can't transfer files with that.

If you mean the protocol(or whatever) telnet, I'm pretty sure you can.

ok now i'm confused. So when i go to the command prompt and type telnet that's the windows telnet? Or are you referring to hyperterminal?

And how is it possible to transfer files using the standard telnet protocol if you have no real connection to your local box?
 

DJFuji

Diamond Member
Oct 18, 1999
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ok gotcha. So telnet protocol by itself doesn't support transfer of files. Am i right in saying that the reason is because you're emulating a terminal and you can't send files in the same way that you can't transfer files with terminal services client? (unless you email them to yourself or something..)
 

GeekDrew

Diamond Member
Jun 7, 2000
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Arg! I forgot about zmodem and kermit... I haven't used telnet that way in YEARS! Like, say, 1995 or so.
 

Linflas

Lifer
Jan 30, 2001
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Originally posted by: GeekDrew
Arg! I forgot about zmodem and kermit... I haven't used telnet that way in YEARS! Like, say, 1995 or so.

Heh that screen shot brought back a flood of memories of my pre-internet BBS days.
 

DJFuji

Diamond Member
Oct 18, 1999
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ok this is what i put. Let me know if i'm off base here...

>>FTP uses port 21 for control connections. Use telnet to connect to port 21. Can you list the contents of a directory or perform a file transfer? Why or why not?
I can connect ok to port 21 on my web server, but cannot transfer files. I believe the reason is that telnet is a terminal emulation program. Thus, like terminal services client, any commands you give it will be executed on the server. Using the command line "FTP" program, however, definitely lets you connect and transfer files.

Some instances of the telnet program can allow for file transfer by using the "zmodem" protocol. However, telnet by itself does not support file transfer or listing.
 

Childs

Lifer
Jul 9, 2000
11,313
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Originally posted by: DJ Fuji
ok this is what i put. Let me know if i'm off base here...

>>FTP uses port 21 for control connections. Use telnet to connect to port 21. Can you list the contents of a directory or perform a file transfer? Why or why not?
I can connect ok to port 21 on my web server, but cannot transfer files. I believe the reason is that telnet is a terminal emulation program. Thus, like terminal services client, any commands you give it will be executed on the server. Using the command line "FTP" program, however, definitely lets you connect and transfer files.

Some instances of the telnet program can allow for file transfer by using the "zmodem" protocol. However, telnet by itself does not support file transfer or listing.


YOu can connect to almost any service on any port using telnet, but without knowing how to communicate with the ftp server youre SOL. I've never tried it with ftp cause I don't know what the ftp server expects in detail, but you can use telnet to connect to sendmail (port 25) and send email maunally. In the quoted example it may be possible if you knew what to send and in what order.
 

Scarpozzi

Lifer
Jun 13, 2000
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I have to use telnet to NMAP into my Email server sometimes. That's an interesting shell to say the least. Every command has a limit of 4 characters for the operator. It makes things difficult to remember because I always want to expand the abbreviations. :p

I agree with buyer... Kermit is your friend.