.\" (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 1.62 2005/09/19 11:37:34 djm Exp $
+.\" $OpenBSD: ssh_config.5,v 1.75 2006/01/20 00:14:55 dtucker Exp $
.Dd September 25, 1999
.Dt SSH_CONFIG 5
.Os
set to
.Dq no
(the default).
-These sessions will reuse the master instance's network connection rather
-than initiating new ones.
+These sessions will try to reuse the master instance's network connection
+rather than initiating new ones, but will fall back to connecting normally
+if the control socket does not exist, or is not listening.
+.Pp
Setting this to
.Dq ask
will cause
X11 and
.Xr ssh-agent 1
forwarding is supported over these multiplexed connections, however the
-display and agent fowarded will be the one belonging to the master
+display and agent forwarded will be the one belonging to the master
connection i.e. it is not possible to forward multiple displays or agents.
.Pp
Two additional options allow for opportunistic multiplexing: try to use a
all three of these escape sequences.
This ensures that shared connections are uniquely identified.
.It Cm DynamicForward
-Specifies that a TCP/IP port on the local machine be forwarded
+Specifies that a TCP port on the local machine be forwarded
over the secure channel, and the application
protocol is then used to determine where to connect to from the
remote machine.
Numeric IP addresses are also permitted (both on the command line and in
.Cm HostName
specifications).
-.It Cm IdentityFile
-Specifies a file from which the user's RSA or DSA authentication identity
-is read.
-The default is
-.Pa ~/.ssh/identity
-for protocol version 1, and
-.Pa ~/.ssh/id_rsa
-and
-.Pa ~/.ssh/id_dsa
-for protocol version 2.
-Additionally, any identities represented by the authentication agent
-will be used for authentication.
-The file name may use the tilde
-syntax to refer to a user's home directory.
-It is possible to have
-multiple identity files specified in configuration files; all these
-identities will be tried in sequence.
.It Cm IdentitiesOnly
Specifies that
.Nm ssh
.Dq yes
or
.Dq no .
-This option is intented for situations where
+This option is intended for situations where
.Nm ssh-agent
offers many different identities.
The default is
.Dq no .
+.It Cm IdentityFile
+Specifies a file from which the user's RSA or DSA authentication identity
+is read.
+The default is
+.Pa ~/.ssh/identity
+for protocol version 1, and
+.Pa ~/.ssh/id_rsa
+and
+.Pa ~/.ssh/id_dsa
+for protocol version 2.
+Additionally, any identities represented by the authentication agent
+will be used for authentication.
+The file name may use the tilde
+syntax to refer to a user's home directory.
+It is possible to have
+multiple identity files specified in configuration files; all these
+identities will be tried in sequence.
.It Cm KbdInteractiveDevices
Specifies the list of methods to use in keyboard-interactive authentication.
Multiple method names must be comma-separated.
The default is to use the server specified list.
+.It Cm LocalCommand
+Specifies a command to execute on the local machine after successfully
+connecting to the server.
+The command string extends to the end of the line, and is executed with
+.Pa /bin/sh .
+This directive is ignored unless
+.Cm PermitLocalCommand
+has been enabled.
.It Cm LocalForward
-Specifies that a TCP/IP port on the local machine be forwarded over
+Specifies that a TCP port on the local machine be forwarded over
the secure channel to the specified host and port from the remote machine.
The first argument must be
.Sm off
.Dq no .
The default is
.Dq yes .
+.It Cm PermitLocalCommand
+Allow local command execution via the
+.Ic LocalCommand
+option or using the
+.Ic !\& Ns Ar command
+escape sequence in
+.Xr ssh 1 .
+The argument must be
+.Dq yes
+or
+.Dq no .
+The default is
+.Dq no .
.It Cm Port
Specifies the port number to connect on the remote host.
Default is 22.
The default is
.Dq yes .
This option applies to protocol version 2 only.
+.It Cm RekeyLimit
+Specifies the maximum amount of data that may be transmitted before the
+session key will be renegotiated.
+The argument is the number of bytes, with an optional suffix of
+.Dq K ,
+.Dq M ,
+or
+.Dq G
+to indicate Kilobytes, Megabytes, or Gigabytes, respectively.
+The default is between
+.Dq 1G
+and
+.Dq 4G ,
+depending on the cipher.
+Note that this option applies to protocol version 2 only.
.It Cm RemoteForward
-Specifies that a TCP/IP port on the remote machine be forwarded over
+Specifies that a TCP port on the remote machine be forwarded over
the secure channel to the specified host and port from the local machine.
The first argument must be
.Sm off
.Cm SendEnv
directives.
The default is not to send any environment variables.
-.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
+Sets the number of server alive messages (see below) which may be
sent without
.Nm ssh
receiving any messages back from the server.
The default value is 3.
If, for example,
.Cm ServerAliveInterval
-(above) is set to 15, and
+(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.
+.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 SmartcardDevice
Specifies which smartcard device to use.
The argument to this keyword is the device
.Pp
To disable TCP keepalive messages, the value should be set to
.Dq no .
+.It Cm Tunnel
+Request starting
+.Xr tun 4
+device forwarding between the client and the server.
+This option also allows requesting layer 2 (ethernet)
+instead of layer 3 (point-to-point) tunneling from the server.
+The argument must be
+.Dq yes ,
+.Dq point-to-point ,
+.Dq ethernet
+or
+.Dq no .
+The default is
+.Dq no .
+.It Cm TunnelDevice
+Force a specified
+.Xr tun 4
+device on the client.
+Without this option, the next available device will be used.
.It Cm UsePrivilegedPort
Specifies whether to use a privileged port for outgoing connections.
The argument must be
andersk / openssh.git / blobdiff