.\" (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 1.58 2005/07/04 00:58:43 djm Exp $
+.\" $OpenBSD: ssh_config.5,v 1.64 2005/10/30 08:43:47 jmc Exp $
.Dd September 25, 1999
.Dt SSH_CONFIG 5
.Os
The default is
.Dq no .
.It Cm BindAddress
-Specify the interface to transmit from on machines with multiple
-interfaces or aliased addresses.
+Use the specified address on the local machine as the source address of
+the connection.
+Only useful on systems with more than one address.
Note that this option does not work if
.Cm UsePrivilegedPort
is set to
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
will continue without connecting to a master instance.
.Pp
X11 and
-.Xr ssh-agent 4
+.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
-connection. I.e. it is not possible to forward multiple displays or agents.
+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
master connection but fall back to creating a new one if one does not already
over the secure channel, and the application
protocol is then used to determine where to connect to from the
remote machine.
-The argument must be a port number.
+.Pp
+The argument must be
+.Sm off
+.Oo Ar bind_address : Oc Ar port .
+.Sm on
+IPv6 addresses can be specified by enclosing addresses in square brackets or
+by using an alternative syntax:
+.Oo Ar bind_address Ns / Oc Ns Ar port .
+By default, the local port is bound in accordance with the
+.Cm GatewayPorts
+setting.
+However, an explicit
+.Ar bind_address
+may be used to bind the connection to a specific address.
+The
+.Ar bind_address
+of
+.Dq localhost
+indicates that the listening port be bound for local use only, while an
+empty address or
+.Sq *
+indicates that the port should be available from all interfaces.
+.Pp
Currently the SOCKS4 and SOCKS5 protocols are supported, and
.Nm ssh
will act as a SOCKS server.