1 files changed, 34 insertions, 2 deletions

diff --git a/ssh_config.5 b/ssh_config.5
index 210da059b..25485f3da 100644
--- a/ssh_config.5
+++ b/ssh_config.5
@@ -127,8 +127,15 @@ Valid arguments are
 If set to
 .Dq yes ,
 passphrase/password querying will be disabled.
+In addition, the 
+.Cm ServerAliveInterval 
+and
+.Cm SetupTimeOut
+options will both be set to 300 seconds by default.
 This option is useful in scripts and other batch jobs where no user
-is present to supply the password.
+is present to supply the password,
+and where it is desirable to detect a
+broken network swiftly.
 The argument must be
 .Dq yes
 or
@@ -559,7 +566,10 @@ from the server,
 will send a message through the encrypted
 channel to request a response from the server.
 The default
-is 0, indicating that these messages will not be sent to the server.
+is 0, indicating that these messages will not be sent to the server,
+or 300 if the
+.Cm BatchMode
+option is set.
 This option applies to protocol version 2 only.
 .It Cm ServerAliveCountMax
 Sets the number of server alive messages (see above) which may be
@@ -588,6 +598,22 @@ If, for example,
 .Cm ServerAliveCountMax
 is left at the default, if the server becomes unresponsive ssh
 will disconnect after approximately 45 seconds.
+.It Cm SetupTimeOut
+Normally,
+.Nm ssh
+blocks indefinitely whilst waiting to receive the ssh banner and other
+setup protocol from the server, during the session setup.
+This can cause
+.Nm ssh
+to hang under certain circumstances.
+If this option is set,
+.Nm ssh
+will give up if no data from the server is received for the specified
+number of seconds.
+The argument must be an integer.
+The default is 0 (disabled), or 300 if
+.Cm BatchMode
+is set.
 .It Cm SmartcardDevice
 Specifies which smartcard device to use.
 The argument to this keyword is the device
@@ -635,6 +661,12 @@ Specifies whether the system should send TCP keepalive messages to the
 other side.
 If they are sent, death of the connection or crash of one
 of the machines will be properly noticed.
+This option only uses TCP keepalives (as opposed to using ssh level
+keepalives), so takes a long time to notice when the connection dies.
+As such, you probably want
+the
+.Cm ServerAliveInterval
+option as well.
 However, this means that
 connections will die if the route is down temporarily, and some people
 find it annoying.