-\versionid $Id: faq.but,v 1.41 2003/01/23 17:01:27 jacob Exp $
+\versionid $Id: faq.but,v 1.59 2004/02/13 12:19:26 jacob 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
development snapshots, in which case testing will be very welcome.
\b try the
-\W{http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist.html}{Wishlist
+\W{http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/}{Wishlist
page}, and see if you can find the feature there. If it's on there,
-it probably \e{hasn't} been implemented.
+and not in the \q{Recently fixed} section, it probably \e{hasn't} been
+implemented.
\S{faq-ssh2}{Question} Does PuTTY support SSH v2?
Yes. SSH v2 support has been available in PuTTY since version 0.50.
-However, currently the \e{default} SSH protocol is v1; to select SSH
-v2 if your server supports both, go to the SSH panel and change the
-\e{Preferred SSH protocol version} option. (The factory default will
-\W{http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/ssh2-default.html}{change to v2}
-in the next full release.)
Public key authentication (both RSA and DSA) in SSH v2 is new in
version 0.52.
ones will not. Adding an option to turn host key checking off
completely is the wrong solution and we will not do it.
+If you have host keys available in the common \c{known_hosts} format,
+we have a script called
+\W{http://cvs.tartarus.org/putty/contrib/kh2reg.py}\c{kh2reg.py}
+to convert them to a Windows .REG file, which can be installed ahead of
+time by double-clicking or using \c{REGEDIT}.
+
\S{faq-server}{Question} Will you write an SSH server for the PuTTY
suite, to go with the client?
\S{faq-pscp-ascii}{Question} Can PSCP or PSFTP transfer files in
ASCII mode?
-Unfortunately not. This is a limitation of the file transfer
-protocols: the SCP and SFTP protocols have no notion of transferring
-a file in anything other than binary mode.
+Unfortunately not.
-SFTP is designed to be extensible, so it's possible that an
-extension might be proposed at some later date that implements ASCII
-transfer. But the PuTTY team can't do anything about it until that
-happens.
+Until recently, this was a limitation of the file transfer protocols:
+the SCP and SFTP protocols had no notion of transferring a file in
+anything other than binary mode. (This is still true of SCP.)
+
+The current draft protocol spec of SFTP proposes a means of
+implementing ASCII transfer. At some point PSCP/PSFTP may implement
+this proposal.
\H{faq-ports} Ports to other operating systems
layer, drawing a clear line between platform-dependent and
platform-independent code. The general intention was for this
porting layer to evolve naturally as part of the process of doing
-the first port; a Unix port is now under way and the plan seems to
-be working so far.
+the first port; a Unix port has now been released and the plan
+seems to be working so far.
\S{faq-ports-general}{Question} What ports of PuTTY exist?
-Currently, release versions of PuTTY only run on full Win32 systems.
-This includes Windows 95, 98, and ME, and it includes Windows NT,
-Windows 2000 and Windows XP. In the development code, partial ports
-to Unix (see \k{faq-unix}) and the Mac OS (see \k{faq-mac-port}).
-are under way.
+Currently, release versions of PuTTY tools only run on full Win32
+systems and Unix. \q{Win32} includes Windows 95, 98, and ME, and it
+includes Windows NT, Windows 2000 and Windows XP.
+
+In the development code, a partial port to the Mac OS (see
+\k{faq-mac-port}) is under way.
Currently PuTTY does \e{not} run on Windows CE (see \k{faq-wince}),
and it does not quite run on the Win32s environment under Windows
3.1 (see \k{faq-win31}).
We do not have release-quality ports for any other systems at the
-present time. If anyone told you we had a Mac port, or an iPaq port,
+present time. If anyone told you we had an EPOC port, or an iPaq port,
or any other port of PuTTY, they were mistaken. We don't.
-\S{faq-unix}{Question} Will there be a port to Unix?
+\S{faq-unix}{Question} Is there a port to Unix?
-It's currently being worked on. If you look at the nightly source
-snapshots, you should find a \c{unix} subdirectory, which should
-build you a Unix port of Plink, and also \c{pterm} - an
-\cw{xterm}-type program which supports the same terminal emulation
-as PuTTY.
+As of 0.54, there are Unix ports of most of the traditional PuTTY
+tools, and also one entirely new application.
-It isn't yet clear whether we will bother combining the terminal
-emulator and network back end into the same process, to provide a
-Unix port of the full GUI form of PuTTY. It wouldn't be as useful a
-thing on Unix as it would be on Windows; its major value would
-probably be as a pathfinding effort for other ports. If anyone
-really wants it, we'd be interested to know why :-)
+If you look at the source release, you should find a \c{unix}
+subdirectory containing \c{Makefile.gtk}, which should build you Unix
+ports of Plink, PuTTY itself, PuTTYgen, PSCP, PSFTP, and also
+\c{pterm} - an \cw{xterm}-type program which supports the same
+terminal emulation as PuTTY. We do not yet have a Unix port of
+Pageant.
-\S{faq-wince}{Question} Will there be a port to Windows CE or PocketPC?
+If you don't have Gtk, you should still be able to build the
+command-line tools.
+
+Note that Unix PuTTY has mostly only been tested on Linux so far;
+portability problems such as BSD-style ptys or different header file
+requirements are expected.
-Probably not in the particularly near future. Despite sharing large
-parts of the Windows API, in practice WinCE doesn't appear to be
-significantly easier to port to than a totally different operating
-system.
+\S{faq-wince}{Question} Will there be a port to Windows CE or PocketPC?
-However, PuTTY on portable devices would clearly be a useful thing,
-so in the long term I hope there will be a WinCE port.
+It's currently being worked on, but it's only in its early stages yet,
+and certainly isn't yet useful. PuTTY on portable devices would
+clearly be a useful thing, so in the long term I hope it can be
+brought up to release quality.
\S{faq-win31}{Question} Is there a port to Windows 3.1?
\S{faq-mac-port}{Question} Will there be a port to the Mac?
-Eventually. The terminal emulation code has been ported, as has the
-saved-settings infrastructure, but networking and a configuration GUI
-still need to be done before the port will be of any use.
+There is a port to the Mac OS in progress. It's just about usable, but
+has an awful lot of gaps and rough edges that will need cleaning up
+before release.
\S{faq-epoc}{Question} Will there be a port to EPOC?
for, it might be a long time before any of us get round to learning
a new system and doing the port for that.
+However, some of the work has been done by other people, and a beta
+port of PuTTY for the Nokia 9200 Communicator series is available
+from \W{http://www.s2.org/putty/}\cw{http://www.s2.org/putty/}
+
\H{faq-embedding} Embedding PuTTY in other programs
\S{faq-dll}{Question} Is the SSH or Telnet code available as a DLL?
\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
\S{faq-psftp-slow}{Question} PSFTP transfers files much slower than PSCP.
-We believe this is because the SFTP and SSH2 protocols are less
-efficient at bulk data transfer than SCP and SSH1, because every
-block of data transferred requires an acknowledgment from the far
-end. It would in theory be possible to queue several blocks of data
-to get round this speed problem, but as yet we haven't done the
-coding. If you really want this fixed, feel free to offer to help.
+The throughput of PSFTP 0.54 should be much better than 0.53b and
+prior; we've added code to the SFTP backend to queue several blocks
+of data rather than waiting for an acknowledgement for each. (The
+SCP backend did not suffer from this performance issue because SCP
+is a much simpler protocol.)
\S{faq-bce}{Question} When I run full-colour applications, I see
areas of black space where colour ought to be.
You almost certainly need to enable the \q{Use background colour to
erase screen} setting in the Terminal panel. Note that if you do
-this in mid-session, it won't take effect until you reset the
+this in mid-session, it may not take effect until you reset the
terminal (see \k{faq-resetterm}).
\S{faq-resetterm}{Question} When I change some terminal settings,
the terminal is reset (by server action, or by you choosing \q{Reset
Terminal} from the System menu) the defaults are restored.
-If you want to change one of these options in the middle of a
-session, you will find that the change does not immediately take
-effect. It will only take effect once you reset the terminal.
+In versions 0.53b and prior, if you change one of these options in
+the middle of a session, you will find that the change does not
+immediately take effect. It will only take effect once you reset
+the terminal.
+
+In version 0.54, the behaviour has changed - changes to these
+settings take effect immediately.
\S{faq-altgr}{Question} I can't type characters that require the
AltGr key.
We already have some, thanks.
+\S{faq-link}{Question} Would you link to my web site from the PuTTY
+web site?
+
+Only if the content of your web page is of definite direct interest
+to PuTTY users. If your content is unrelated, or only tangentially
+related, to PuTTY, then the link would simply be advertising for
+you.
+
+One very nice effect of the Google ranking mechanism is that by and
+large, the most popular web sites get the highest rankings. This
+means that when an ordinary person does a search, the top item in
+the search is very likely to be a high-quality site or the site they
+actually wanted, rather than the site which paid the most money for
+its ranking.
+
+The PuTTY web site is held in high esteem by Google, for precisely
+this reason: lots of people have linked to it simply because they
+like PuTTY, without us ever having to ask anyone to link to us. We
+feel that it would be an abuse of this esteem to use it to boost the
+ranking of random advertisers' web sites. If you want your web site
+to have a high Google ranking, we'd prefer that you achieve this the
+way we did - by being good enough at what you do that people will
+link to you simply because they like you.
+
+If you have software based on PuTTY, or specifically designed to
+interoperate with PuTTY, or in some other way of genuine interest to
+PuTTY users, then we will probably be happy to add a link to you on
+our Links page. And if you're running a mirror of the PuTTY web
+site, we're \e{definitely} interested.
+
\S{faq-sourceforge}{Question} Why don't you move PuTTY to
SourceForge?
There isn't one, that we know of.
-If someone else wants to set up a mailing list for PuTTY users to
-help each other with common problems, that would be fine with us;
-but the PuTTY team would almost certainly not have the time to read
-it, so any questions the list couldn't answer would have to be
-forwarded on to us by the questioner. In any case, it's probably
-better to use the established newsgroup \cw{comp.security.ssh} for
-this purpose.
+If someone else wants to set up a mailing list or other forum for
+PuTTY users to help each other with common problems, that would be
+fine with us, though the PuTTY team would almost certainly not have the
+time to read it. It's probably better to use the established
+newsgroup \cw{comp.security.ssh} for this purpose.
\S{faq-donations}{Question} How can I donate to PuTTY development?
buy from Crazy Aaron's Putty World, at
\W{http://www.puttyworld.com}\cw{www.puttyworld.com}.
-\S{faq-pronounce}{Question} How do I pronounce PuTTY?
+\S{faq-meaning}{Question} What does \q{PuTTY} mean?
+
+It's the name of a popular SSH and Telnet client. Any other meaning
+is in the eye of the beholder. It's been rumoured that \q{PuTTY}
+is the antonym of \q{\cw{getty}}, or that it's the stuff that makes your
+Windows useful, or that it's a kind of plutonium Teletype. We
+couldn't possibly comment on such allegations.
+
+\S{faq-pronounce}{Question} How do I pronounce \q{PuTTY}?
-Exactly like the normal word \q{putty}. Just like the stuff you put
-on window frames. (One of the reasons it's called PuTTY is because
-it makes Windows usable. :-)
+Exactly like the English word \q{putty}, which we pronounce
+/\u02C8{'}p\u028C{V}t\u026A{I}/.
projects / u / mdw / putty / blobdiff