It's a new year (and we've even made a code checkin).

[u/mdw/putty] / doc / config.but

diff --git a/doc/config.but b/doc/config.but
index 98b4a7e..16d1589 100644 (file)
--- a/doc/config.but
+++ b/doc/config.but
@@ -1700,8 +1700,13 @@ TCP keepalives are disabled by default.
 \cfg{winhelp-topic}{connection.ipversion}
 
 This option allows the user to select between the old and new
-Internet protocols and addressing schemes (\i{IPv4} and \i{IPv6}). The
-default setting is \q{Auto}, which means PuTTY will do something
+Internet protocols and addressing schemes (\i{IPv4} and \i{IPv6}).
+The selected protocol will be used for most outgoing network
+connections (including connections to \I{proxy}proxies); however,
+tunnels have their own configuration, for which see
+\k{config-ssh-portfwd-address-family}.
+
+The default setting is \q{Auto}, which means PuTTY will do something
 sensible and try to guess which protocol you wanted. (If you specify
 a literal \i{Internet address}, it will use whichever protocol that
 address implies. If you provide a \i{hostname}, it will see what kinds
@@ -2788,6 +2793,9 @@ incoming connections in both IPv4 and (if available) IPv6
 \b for a remote-to-local port forwarding, PuTTY will choose a
 sensible protocol for the outgoing connection.
 
+This overrides the general Internet protocol version preference
+on the Connection panel (see \k{config-address-family}).
+
 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 \i{Linux} does
@@ -2978,6 +2986,22 @@ would expect.
 
 This is an SSH-2-specific bug.
 
+\S{config-ssh-bug-maxpkt2} \q{Ignores SSH-2 \i{maximum packet size}}
+
+\cfg{winhelp-topic}{ssh.bugs.maxpkt2}
+
+When an SSH-2 channel is set up, each end announces the maximum size
+of data packet that it is willing to receive for that channel.  Some
+servers ignore PuTTY's announcement and send packets larger than PuTTY
+is willing to accept, causing it to report \q{Incoming packet was
+garbled on decryption}.
+
+If this bug is detected, PuTTY never allows the channel's
+\i{flow-control window} to grow large enough to allow the server to
+send an over-sized packet.  If this bug is enabled when talking to a
+correct server, the session will work correctly, but download
+performance will be less than it could be.
+
 \H{config-serial} The Serial panel
 
 The \i{Serial} panel allows you to configure options that only apply