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Frequently Asked Questions

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Most recent update: Thu Feb 8 07:40:52 2018



This document replaces the original Kermit FAQ, which can still be accessed HERE. The original FAQ is organized chronologically; this new one is organized by topic and contains mainly just links to other pages. For example:

This document pertains to Kermit "as a whole". Major Kermit programs, in turn, have their own specific FAQs, e.g.:

[ Contents ] [ Kermit Home ]

Which Kermit Program(s) Do I Need?

Kermit software can be used for many purposes. If all you want is a terminal emulator for serial or network connections for your Windows or DOS PC, use Kermit 95 or MS-DOS Kermit, as appropriate. If you want to transfer files, you'll need two Kermit programs, one for each end of the connection. For example, if you want to make a connection from Windows XP to a Sun Solaris server, you'll need Kermit 95 for Windows and C-Kermit for Solaris.

Here's a quick overview:

UNIX, (Open)VMS, QNX, OS-9, Plan 9, AOS/VS, VOS
(Full-featured network and serial communications and scripting)

UNIX only
(File transfer only).

Windows 95, 98, Millenium Edition, NT, 2000, XP, Vista, 7, ...
Kermit 95
(Full-featured network and serial communications and scripting)

Kermit 95
(Full-featured network and serial communications and scripting)

MS-DOS, PC-DOS, DR-DOS, or Windows 3.11 or earlier
MS-DOS Kermit
(Full-featured network and serial communications and scripting)
Note:MS-DOS Kermit is not supported on Windows 95/98/ME/NT/2000/XP or OS/2, not even in a "DOS window".

IBM mainframes with VM/CMS, MVS/TSO, or MUSIC
IBM Mainframe Kermit


[ Contents ] [ Kermit Home ]

Where To Find Things

The Kermit Project started in 1981 and has been developing and accumulating software ever since, so there is a lot of stuff here. Originally it was available only by mail order on magnetic tape. When the ARPANET (later Internet) became more widely available, the master tape directories were made available for public FTP access. Eventually the demand for tapes dwindled away but we still have thousands of files organized "by tape", with naming conventions designed for flat and unstructured tape archives with short filenames. This made FTP access somewhat difficult. But that's all fixed now with the new archive page that allows every Kermit program ever written to be fetched by a single click. CLICK HERE to access the Kermit archive at Columbia University. [ Contents ] [ Kermit Home ]

Common Misconceptions

Click on any of the following to read about it:

Others discussed here:

Don't Use Telnet, Use SSH!

On the newsgroups, whenever anyone asks a question that contains the word "telnet" (or "ftp"), the answer comes back within milliseconds: Don't use Telnet, use SSH! (or Don't use FTP, use SCP!) (or SFTP). This confuses two orthogonal concepts:

  1. Virtual Terminal (or File Transfer) protocols
  2. Security

There's nothing wrong with Telnet. In fact it's far superior to SSH as a virtual terminal protocol in terms of features and extensibility, not to mention platform neutrality. Of course clear-text Telnet is insecure because passwords travel in the clear across the network, but apparently few people realize that secure Telnet clients and servers have been available for years, and these are more secure than SSH for reasons explained HERE. (If you don't bother to follow the link, the short version is manageability, especially regarding recovery from compromised keys.) Increasingly, Internet standard security methods such as Kerberos and SSL/TLS are included in standard distributions of Unix (Linux, FreeBSD, OpenBSD, AIX, Solaris, HP-UX, ...), VMS, and other operating systems, supported in their Telnet and/or FTP servers and/or clients. And of course they are also supported by C-Kermit for Unix and VMS and by Kermit 95 for Windows (which also supports SSH v1/v2).

Similarly for FTP. SCP and SFTP are not only not platform neutral, they're diversity-hostile. They transfer files only in binary mode, which mangles text files across different platforms, to the same degree the platforms' text-file record formats and character sets differ. An extreme example would be a Variable-Block format EBCDIC text file on an IBM mainframe, binary transfer of which to Unix would do you little good indeed. FTP was designed with diversity in mind and secure versions are available.

Of course SSH has its place, but you should use it with your eyes open, especially from Windows (where key files are easily stolen). SSH is best suited for trivial cross-realm applications. For example, if you have guest IDs at other sites for building an application on different platforms. Formerly Telnet and FTP would be used for this but now these paths tend to be blocked. However, even if the remote site has Kerberos service or X.509 certificates, it would be unnecessarily time-consuming to set up the cross-realm authentication and/or ticket forwarding for little one-shot jobs like this. In this case, SSH with manual password authentication is fine.

But for more serious work, especially within large organizations such as universities, corporations, laboratories, and government agencies, where your whole online identity is at stake, a manageable centralized security architecture is essential.

[ Contents ] [ Kermit Home ] [ Kermit Security Reference ] [ The Kermit FTP Client ]


Kermit software licensing is explained HERE. As of July 1, 2011, most Kermit software is Open Source.

[ Contents ] [ Kermit Home ]

General Questions

[ Contents ] [ Kermit Home ]

File Transfer

[ Contents ] [ Kermit Home ]

Terminal Emulation

[ Contents ] [ Kermit Home ]

Modems and Dialing

Perhaps the most common problem in this area is that people "set modem type hayes" or (older syntax) "set modem hayes", thinking this means "any modem that uses AT commands." No, Kermit's "hayes" modem type is the actual Hayes 1200 or 2400 SmartModem from long ago. These modems did not support error detection and correction, compression, flow control, or speed buffering. If you use Kermit's "set modem type" command as documented to pick the kind of modem you are actually dialing or (in most cases) just go with the default, which in recent Kermit versions is "generic-high-speed", dialing should work. If you have trouble, use "set dial display on" to watch the dialog between Kermit and the modem, and then consult your modem manual to see what's wrong.

[ Contents ] [ Kermit Home ]

Kermit 95

Runs on: Windows 95, Windows 98, Windows ME, Windows NT, Windows 2000, Windows XP, OS/2
Current version: 2.1.3
Released: 1 January 2003
FAQ: See the Kermit 95 FAQ

[ Contents ] [ Kermit 95 ] [ Kermit Home ]


Runs on: UNIX, VMS, VOS, AOS/VS, QNX, OS-9, Plan 9, BeOS, Commodore Amiga
Current version: 9.0.300
Released: 30 June 2011
FAQ: See the C-Kermit FAQ, plus the following.

NOTE: "UNIX" is a general term covering the many operating systems that descended from the original Bell Labs UNIX operating system. Examples include: Linux, Mac OS X, FreeBSD, NetBSD, OpenBSD, Solaris, SunOS, AIX, HP-UX, IRIX, OPENSTEP, NeXTSTEP, System V, Tru64, OSF/1, DG/UX, Unixware, Xenix, OpenServer, BSDI/OS, Ultrix, Digital UNIX, SINIX, and many more (for a longer list, CLICK HERE).

[ Contents ] [ C-Kermit ] [ Kermit Home ]

MS-DOS Kermit

Runs on: Windows 3.x and earlier, MS-DOS, PC-DOS, DR-DOS, etc.
Current version: 3.15
Released: 15 Sep 1997

[ Contents ] [ MS-DOS Kermit ] [ Kermit Home ]

IBM Mainframe Related

[ Contents ] [ IBM Mainframe Kermit ] [ Kermit Home ]

The Kermit Project hosted by Panix.com / kermit@kermitproject.org / 8 February 2018