+.It Cm SendEnv
+Specifies what variables from the local
+.Xr environ 7
+should be sent to the server.
+Note that environment passing is only supported for protocol 2.
+The server must also support it, and the server must be configured to
+accept these environment variables.
+Refer to
+.Cm AcceptEnv
+in
+.Xr sshd_config 5
+for how to configure the server.
+Variables are specified by name, which may contain wildcard characters.
+Multiple environment variables may be separated by whitespace or spread
+across multiple
+.Cm SendEnv
+directives.
+The default is not to send any environment variables.
+.Pp
+See
+.Sx PATTERNS
+for more information on patterns.
+.It Cm ServerAliveCountMax
+Sets the number of server alive messages (see below) which may be
+sent without
+.Xr ssh 1
+receiving any messages back from the server.
+If this threshold is reached while server alive messages are being sent,
+ssh will disconnect from the server, terminating the session.
+It is important to note that the use of server alive messages is very
+different from
+.Cm TCPKeepAlive
+(below).
+The server alive messages are sent through the encrypted channel
+and therefore will not be spoofable.
+The TCP keepalive option enabled by
+.Cm TCPKeepAlive
+is spoofable.
+The server alive mechanism is valuable when the client or
+server depend on knowing when a connection has become inactive.
+.Pp
+The default value is 3.
+If, for example,
+.Cm ServerAliveInterval
+(see below) is set to 15 and
+.Cm ServerAliveCountMax
+is left at the default, if the server becomes unresponsive,
+ssh will disconnect after approximately 45 seconds.
+This option applies to protocol version 2 only.
+.It Cm ServerAliveInterval
+Sets a timeout interval in seconds after which if no data has been received
+from the server,
+.Xr ssh 1
+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.
+This option applies to protocol version 2 only.