-\versionid $Id: faq.but,v 1.49 2003/10/15 12:09:24 jacob Exp $
+\versionid $Id: faq.but,v 1.52 2004/01/21 17:11:55 simon Exp $
\A{faq} PuTTY FAQ
This FAQ is published on the PuTTY web site, and also provided as an
appendix in the manual.
+\H{faq-intro} Introduction
+
+\S{faq-what} What is PuTTY?
+
+PuTTY is a client program for the SSH, Telnet and Rlogin network
+protocols.
+
+These protocols are all used to run a remote session on a computer,
+over a network. PuTTY implements the client end of that session: the
+end at which the session is displayed, rather than the end at which
+it runs.
+
+In really simple terms: you run PuTTY on a Windows machine, and tell
+it to connect to (for example) a Unix machine. PuTTY opens a window.
+Then, anything you type into that window is sent straight to the
+Unix machine, and everything the Unix machine sends back is
+displayed in the window. So you can work on the Unix machine as if
+you were sitting at its console, while actually sitting somewhere
+else.
+
\H{faq-support} Features supported in PuTTY
In general, if you want to know if PuTTY supports a particular
\S{faq-incorrect-mac}{Question} Why do I see \q{Incorrect MAC
received on packet}?
-This is due to a bug in old SSH 2 servers distributed by
-\cw{ssh.com}. Version 2.3.0 and below of their SSH 2 server
+One possible cause of this that used to be common is a bug in old
+SSH 2 servers distributed by \cw{ssh.com}. (This is not the only
+possible cause; see \k{errors-crc} in the documentation.)
+Version 2.3.0 and below of their SSH 2 server
constructs Message Authentication Codes in the wrong way, and
expects the client to construct them in the same wrong way. PuTTY
constructs the MACs correctly by default, and hence these old