Je crois que les paramètres que vous recherchez sont les suivants :
ServerAliveInterval 120
ServerAliveCountMax 2
De man ssh_config :
ServerAliveCountMax
Sets the number of server alive messages (see below) which may be sent
without 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 dif
ferent from TCPKeepAlive (below). The server alive messages are sent
through the encrypted channel and therefore will not be spoofable.
The TCP keepalive option enabled by TCPKeepAlive is spoofable. The
server alive mechanism is valuable when the client or server depend on
knowing when a connection has become inactive.
The default value is 3. If, for example, ServerAliveInterval (see
below) is set to 15 and ServerAliveCountMax is left at the default, if
the server becomes unresponsive, ssh will disconnect after approxi
mately 45 seconds.
ServerAliveInterval
Sets a timeout interval in seconds after which if no data has been
received from the server, 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.
