+will send a message through the encrypted
+channel to request a response from the client.
+The default
+is 0, indicating that these messages will not be sent to the client.
+This option applies to protocol version 2 only.
+.It Cm ClientAliveCountMax
+Sets the number of client alive messages (see above) which may be
+sent without
+.Nm
+receiving any messages back from the client. If this threshold is
+reached while client alive messages are being sent,
+.Nm
+will disconnect the client, terminating the session. It is important
+to note that the use of client alive messages is very different from
+.Cm Keepalive
+(below). The client alive messages are sent through the
+encrypted channel and therefore will not be spoofable. The TCP keepalive
+option enabled by
+.Cm Keepalive
+is spoofable. The client 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
+.Cm ClientAliveInterval
+(above) is set to 15, and
+.Cm Keepalive is left at the default, unresponsive ssh clients
+will be disconnected after approximately 45 seconds.