=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/ssh_config.5,v retrieving revision 1.27 retrieving revision 1.28 diff -u -r1.27 -r1.28 --- src/usr.bin/ssh/ssh_config.5 2003/12/14 12:37:21 1.27 +++ src/usr.bin/ssh/ssh_config.5 2003/12/16 15:49:51 1.28 @@ -34,7 +34,7 @@ .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. .\" -.\" $OpenBSD: ssh_config.5,v 1.27 2003/12/14 12:37:21 markus Exp $ +.\" $OpenBSD: ssh_config.5,v 1.28 2003/12/16 15:49:51 markus Exp $ .Dd September 25, 1999 .Dt SSH_CONFIG 5 .Os @@ -552,6 +552,42 @@ The default is .Dq yes . Note that this option applies to protocol version 1 only. +.It Cm ServerAliveInterval +Sets a timeout interval in seconds after which if no data has been received +from the server, +.Nm ssh +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. +.It Cm ServerAliveCountMax +Sets the number of server alive messages (see above) which may be +sent without +.Nm ssh +receiving any messages back from the server. +If this threshold is reached while server alive messages are being sent, +.Nm 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 +(above) is set to 15, and +.Cm ServerAliveCountMax +is left at the default, if the server becomes unresponsive ssh +will disconnect after approximately 45 seconds. .It Cm SmartcardDevice Specifies which smartcard device to use. The argument to this keyword is the device