\q{Default Settings} entry in the saved sessions list, with a single
click. Then press the \q{Save} button.
+\lcont{
Note that PuTTY does not allow you to save a host name into the
Default Settings entry. This ensures that when PuTTY is started up,
the host name box is always empty, so a user can always just type in
a host name and connect.
+}
If there is a specific host you want to store the details of how to
connect to, you should create a saved session, which will be
saved session name.) Then press the \q{Save} button. Your saved
session name should now appear in the list box.
+\lcont{
+You can also save settings in mid-session, from the \q{Change Settings}
+dialog. Settings changed since the start of the session will be saved
+with their current values; as well as settings changed through the
+dialog, this includes changes in window size, window title changes
+sent by the server, and so on.
+}
+
\b To reload a saved session: single-click to select the session
name in the list box, and then press the \q{Load} button. Your saved
settings should all appear in the configuration panel.
\b To modify a saved session: first load it as described above. Then
make the changes you want. Come back to the Session panel, and press
the \q{Save} button. The new settings will be saved over the top of
-the old ones
+the old ones.
\lcont{
To save the new settings under a different name, you can enter the new
PuTTY will not rekey due to elapsed time. The SSH-2 protocol
specification recommends a timeout of at most 60 minutes.
+You might have a need to disable time-based rekeys completely for the same
+reasons that keepalives aren't always helpful. If you anticipate
+suffering a network dropout of several hours in the middle of an SSH
+connection, but were not actually planning to send \e{data} down
+that connection during those hours, then an attempted rekey in the
+middle of the dropout will probably cause the connection to be
+abandoned, whereas if rekeys are disabled then the connection should
+in principle survive (in the absence of interfering firewalls). See
+\k{config-keepalive} for more discussion of these issues; for these
+purposes, rekeys have much the same properties as keepalives.
+(Except that rekeys have cryptographic value in themselves, so you
+should bear that in mind when deciding whether to turn them off.)
+Note, however, the the SSH \e{server} can still initiate rekeys.
+
\b \q{Max data before rekey} specifies the amount of data (in bytes)
that is permitted to flow in either direction before a rekey is
initiated. If this is set to zero, PuTTY will not rekey due to
}
-PuTTY can be prevented from initiating a rekey entirely by setting
-both of these values to zero. (Note, however, that the SSH
-\e{server} may still initiate rekeys.)
-
-You might have a need to disable rekeys completely for the same
-reasons that keepalives aren't always helpful. If you anticipate
-suffering a network dropout of several hours in the middle of an SSH
-connection, but were not actually planning to send \e{data} down
-that connection during those hours, then an attempted rekey in the
-middle of the dropout will probably cause the connection to be
-abandoned, whereas if rekeys are disabled then the connection should
-in principle survive (in the absence of interfering firewalls). See
-\k{config-keepalive} for more discussion of these issues; for these
-purposes, rekeys have much the same properties as keepalives.
-(Except that rekeys have cryptographic value in themselves, so you
-should bear that in mind when deciding whether to turn them off.)
+Disabling data-based rekeys entirely is a bad idea. The integrity,
+and to a lesser extent, confidentiality of the SSH-2 protocol depend
+in part on rekeys occuring before a 32-bit packet sequence number
+wraps around. Unlike time-based rekeys, data-based rekeys won't occur
+when the SSH connection is idle, so they shouldn't cause the same
+problems. The SSH-1 protocol, incidentally, has even weaker integrity
+protection than SSH-2 without rekeys.
\H{config-ssh-auth} The Auth panel
See \k{using-port-forwarding} for more information on how this
works and its restrictions.
+In place of port numbers, you can enter service names, if they are
+known to the local system. For instance, in the \q{Destination} box,
+you could enter \c{popserver.example.com:pop3}.
+
You can modify the currently active set of port forwardings in
-mid-session using \q{Change Settings}. If you delete a local or
-dynamic port forwarding in mid-session, PuTTY will stop listening
-for connections on that port, so it can be re-used by another
-program. If you delete a remote port forwarding, note that:
+mid-session using \q{Change Settings} (see \k{using-changesettings}).
+If you delete a local or dynamic port forwarding in mid-session, PuTTY
+will stop listening for connections on that port, so it can be re-used
+by another program. If you delete a remote port forwarding, note that:
\b The SSHv1 protocol contains no mechanism for asking the server to
stop listening on a remote port.
least be reasonably sure that server-side programs can no longer
access the service at your end of the port forwarding.
+If you delete a forwarding, any existing connections established using
+that forwarding remain open. Similarly, changes to global settings
+such as \q{Local ports accept connections from other hosts} only take
+effect on new forwardings.
+
\S{config-ssh-portfwd-localhost} Controlling the visibility of
forwarded ports
\b for a remote-to-local port forwarding, PuTTY will choose a
sensible protocol for the outgoing connection.
-\# FIXME: work out what this paragraph means, reword it for clarity,
-\# and reinstate it.
-Note that on Windows the address space for IPv4 and IPv6 is
-completely disjunct, so listening on IPv6 won't make PuTTY listen on
-IPv4. This behaviour may be different on most remote hosts when they
-are not operating Windows.
+Note that some operating systems may listen for incoming connections
+in IPv4 even if you specifically asked for IPv6, because their IPv4
+and IPv6 protocol stacks are linked together. Apparently Linux does
+this, and Windows does not. So if you're running PuTTY on Windows
+and you tick \q{IPv6} for a local or dynamic port forwarding, it
+will \e{only} be usable by connecting to it using IPv6; whereas if
+you do the same on Linux, you can also use it with IPv4. However,
+ticking \q{Auto} should always give you a port which you can connect
+to using either protocol.
\H{config-ssh-bugs} The Bugs panel
This is an SSH2-specific bug.
+\S{config-ssh-bug-rekey} \q{Handles key re-exchange badly}
+
+\cfg{winhelp-topic}{ssh.bugs.rekey2}
+
+Some SSH servers cannot cope with repeat key exchange at
+all, and will ignore attempts by the client to start one. Since
+PuTTY pauses the session while performing a repeat key exchange, the
+effect of this would be to cause the session to hang after an hour
+(unless you have your rekey timeout set differently; see
+\k{config-ssh-kex-rekey} for more about rekeys).
+Other, very old, SSH servers handle repeat key exchange even more
+badly, and disconnect upon receiving a repeat key exchange request.
+
+If this bug is detected, PuTTY will never initiate a repeat key
+exchange. If this bug is enabled when talking to a correct server,
+the session should still function, but may be less secure than you
+would expect.
+
+This is an SSH2-specific bug.
+
\H{config-file} Storing configuration in a file
PuTTY does not currently support storing its configuration in a file
projects / u / mdw / putty / blobdiff