-.It Fl D
-When this option is specified
-.Nm
-will not detach and does not become a daemon.
-This allows easy monitoring of
-.Nm sshd .
-.It Fl 4
-Forces
-.Nm
-to use IPv4 addresses only.
-.It Fl 6
-Forces
-.Nm
-to use IPv6 addresses only.
-.El
-.Sh CONFIGURATION FILE
-.Nm
-reads configuration data from
-.Pa /etc/sshd_config
-(or the file specified with
-.Fl f
-on the command line).
-The file contains keyword-argument pairs, one per line.
-Lines starting with
-.Ql #
-and empty lines are interpreted as comments.
-.Pp
-The possible
-keywords and their meanings are as follows (note that
-keywords are case-insensitive and arguments are case-sensitive):
-.Bl -tag -width Ds
-.It Cm AFSTokenPassing
-Specifies whether an AFS token may be forwarded to the server.
-Default is
-.Dq yes .
-.It Cm AllowGroups
-This keyword can be followed by a list of group names, separated
-by spaces.
-If specified, login is allowed only for users whose primary
-group or supplementary group list matches one of the patterns.
-.Ql \&*
-and
-.Ql ?
-can be used as
-wildcards in the patterns.
-Only group names are valid; a numerical group ID isn't recognized.
-By default login is allowed regardless of the group list.
-.Pp
-.It Cm AllowTcpForwarding
-Specifies whether TCP forwarding is permitted.
-The default is
-.Dq yes .
-Note that disabling TCP forwarding does not improve security unless
-users are also denied shell access, as they can always install their
-own forwarders.
-.Pp
-.It Cm AllowUsers
-This keyword can be followed by a list of user names, separated
-by spaces.
-If specified, login is allowed only for users names that
-match one of the patterns.
-.Ql \&*
-and
-.Ql ?
-can be used as
-wildcards in the patterns.
-Only user names are valid; a numerical user ID isn't recognized.
-By default login is allowed regardless of the user name.
-If the pattern takes the form USER@HOST then USER and HOST
-are separately checked, allowing you to restrict logins to particular
-users from particular hosts.
-.Pp
-.It Cm AuthorizedKeysFile
-Specifies the file that contains the public keys that can be used
-for user authentication.
-.Cm AuthorizedKeysFile
-may contain tokens of the form %T which are substituted during connection
-set-up. The following tokens are defined; %% is replaces by a literal '%',
-%h is replaced by the home directory of the user being authenticated and
-%u is replaced by the username of that user.
-After expansion,
-.Cm AuthorizedKeysFile
-is taken to be an absolute path or one relative to the user's home
-directory.
-The default is
-.Dq .ssh/authorized_keys
-.It Cm Banner
-In some jurisdictions, sending a warning message before authentication
-may be relevant for getting legal protection.
-The contents of the specified file are sent to the remote user before
-authentication is allowed.
-This option is only available for protocol version 2.
-.Pp
-.It Cm ChallengeResponseAuthentication
-Specifies whether challenge response authentication is allowed.
-All authentication styles from
-.Xr login.conf 5
-are supported.
-The default is
-.Dq yes .
-.It Cm Ciphers
-Specifies the ciphers allowed for protocol version 2.
-Multiple ciphers must be comma-separated.
-The default is
-.Dq aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour.
-.It Cm ClientAliveInterval
-Sets a timeout interval in seconds after which if no data has been received
-from the client,
-.Nm
-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. You want to use the client
-alive mechanism when you are basing something important on
-clients having an active connection to the server.
-.Pp
-The default value is 3. If you set
-.Cm ClientAliveInterval
-(above) to 15, and leave this value at the default, unresponsive ssh clients
-will be disconnected after approximately 45 seconds.
-.It Cm DenyGroups
-This keyword can be followed by a number of group names, separated
-by spaces.
-Users whose primary group or supplementary group list matches
-one of the patterns aren't allowed to log in.
-.Ql \&*
-and
-.Ql ?
-can be used as
-wildcards in the patterns.
-Only group names are valid; a numerical group ID isn't recognized.
-By default login is allowed regardless of the group list.
-.Pp
-.It Cm DenyUsers
-This keyword can be followed by a number of user names, separated
-by spaces.
-Login is disallowed for user names that match one of the patterns.
-.Ql \&*
-and
-.Ql ?
-can be used as wildcards in the patterns.
-Only user names are valid; a numerical user ID isn't recognized.
-By default login is allowed regardless of the user name.
-.It Cm GatewayPorts
-Specifies whether remote hosts are allowed to connect to ports
-forwarded for the client.
-The argument must be
-.Dq yes
-or
-.Dq no .
-The default is
-.Dq no .
-.It Cm HostbasedAuthentication
-Specifies whether rhosts or /etc/hosts.equiv authentication together
-with successful public key client host authentication is allowed
-(hostbased authentication).
-This option is similar to
-.Cm RhostsRSAAuthentication
-and applies to protocol version 2 only.
-The default is
-.Dq no .
-.It Cm HostKey
-Specifies the file containing the private host keys (default
-.Pa /etc/ssh_host_key )
-used by SSH protocol versions 1 and 2.
-Note that
-.Nm
-will refuse to use a file if it is group/world-accessible.
-It is possible to have multiple host key files.
-.Dq rsa1
-keys are used for version 1 and
-.Dq dsa
-or
-.Dq rsa
-are used for version 2 of the SSH protocol.
-.It Cm IgnoreRhosts
-Specifies that
-.Pa .rhosts
-and
-.Pa .shosts
-files will not be used in
-.Cm RhostsAuthentication ,
-.Cm RhostsRSAAuthentication
-or
-.Cm HostbasedAuthentication .
-.Pp
-.Pa /etc/hosts.equiv
-and
-.Pa /etc/shosts.equiv
-are still used.
-The default is
-.Dq yes .
-.It Cm IgnoreUserKnownHosts
-Specifies whether
-.Nm
-should ignore the user's
-.Pa $HOME/.ssh/known_hosts
-during
-.Cm RhostsRSAAuthentication