# SSH configuration file.
+# Copyright (C) 2011-2012 Simon Ruderich
+#
+# This file is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This file is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this file. If not, see <http://www.gnu.org/licenses/>.
+
+# Undocumented (and not very well tested) feature. This drops the connection
+# after 5 seconds of inactivity. Thanks to shad0VV in #openssh on Freenode
+# (2012-11-04 18:40 CET) for telling me about this undocumented feature.
+#
+# ServerAliveCountMax 0
+# ServerAliveInterval 5
+
# Rules for all hosts.
Host *
# to local X11!
ForwardX11Trusted no
-# If -M is used store the control master socket in ~/.ssh. Necessary for
-# ControlMaster to work.
+# Allow using -M (ControlMaster) to create a master SSH session which
+# "tunnels" other connections to the same host, thus reducing the number of
+# authentications (which are relatively slow) and TCP connections.
ControlPath ~/.ssh/master-%l-%h-%p-%r
+# Abort if not all requested port forwardings can be set up.
+ ExitOnForwardFailure yes
+
# Don't send any environment variables.
SendEnv
+# Check host IP in known_hosts when connecting to detect DNS spoofing.
+ CheckHostIP yes
# Ask before adding any host keys to ~/.ssh/known_hosts.
StrictHostKeyChecking ask