Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!rutgers!psuvax1!ukma!xanth!xanth.cs.odu.edu!tadguy From: tadguy@cs.odu.edu (Tad Guy) Newsgroups: comp.sys.amiga Subject: Re: telnet access to FTPD Message-ID: Date: 10 Mar 90 02:05:55 GMT References: <778@tau.sm.luth.se> Sender: news@cs.odu.edu Distribution: comp Organization: Old Dominion University, Norfolk, VA Lines: 47 In-reply-to: d88-mbe@sm.luth.se's message of 9 Mar 90 18:27:02 GMT [ This really doesn't belong in comp.sys.amiga... ] In article <778@tau.sm.luth.se> d88-mbe@sm.luth.se (Michael Bergman) writes: > It's possible to access the FTP-server of a foreign host via telnet > by doing "telnet hostname 21", where 21 is the ftp-service port. > You're then thrown directly into the FTPD and can log in with USER > anonymous and PASS xxx@yyy. Various commands are available, HELP > shows them all. Right, though it's more accurate to say that you're communicating with the ftpd (the ftp server process) on the remote host. > though you can issue the command LIST, no data connection is > established between the host and telnet(??)... Right. > Is it possible to call telnet from an Amiga, connect to a foreign host's > FTPD and have a proper connection set up so that data can be transferred > between the host and the Amiga? Or is it nessecary to have a real UN*X host > to do this? If you have the ftp program on your Amiga (since you have telnet, you really should also have ftp), all works as it should. Why? Well... When you issue a command that requires the transfer of data (such as STOR, RETR, LIST, NLST, etc), ftpd attempts to open a *second* TCP connection to your host on the ftp-data port (#20), unless you've previously used the PORT command to tell the ftpd process specifically where to connect. This means that your side of the connection must have *previously* begun listeneing for connections on that port. Telnet doesn't do this (it wasn't designed to, and it's outside the scope of telnet to do such things; that's why ftp exists). When the transfer is completed, the second connection is closed. So, with normal telnet clients, the answer is ``no''... (You could hack some kind of listening code into telnet, but that's not the right solution). > If anyone decides to post an answer to this, could you please EMAIL me a > copy of that posting? Done. You might also what to check out RFC959, which defines FTP. ...tad