# 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