ssh_config.0

OpenSSL Source code for SFTP, SSH, and many others

             porarily, and some people find it annoying.

             The default is ``yes'' (to send keepalives), and the client will
             notice if the network goes down or the remote host dies.  This is
             important in scripts, and many users want it too.

             To disable keepalives, the value should be set to ``no''.

     KerberosAuthentication
             Specifies whether Kerberos authentication will be used.  The
             argument to this keyword must be ``yes'' or ``no''.

     KerberosTgtPassing
             Specifies whether a Kerberos TGT will be forwarded to the server.
             This will only work if the Kerberos server is actually an AFS
             kaserver.  The argument to this keyword must be ``yes'' or
             ``no''.

     LocalForward
             Specifies that a TCP/IP 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 a port number, and
             the second must be host:port.  IPv6 addresses can be specified
             with an alternative syntax: host/port.  Multiple forwardings may
             be specified, and additional forwardings can be given on the comM--
             mand line.  Only the superuser can forward privileged ports.

     LogLevel
             Gives the verbosity level that is used when logging messages from
             ssh.  The possible values are: QUIET, FATAL, ERROR, INFO, VERM--
             BOSE, DEBUG, DEBUG1, DEBUG2 and DEBUG3.  The default is INFO.
             DEBUG and DEBUG1 are equivalent.  DEBUG2 and DEBUG3 each specify
             higher levels of verbose output.

     MACs    Specifies the MAC (message authentication code) algorithms in
             order of preference.  The MAC algorithm is used in protocol verM--
             sion 2 for data integrity protection.  Multiple algorithms must
             be comma-separated.  The default is
             ``hmac-md5,hmac-sha1,hmac-ripemd160,hmac-sha1-96,hmac-md5-96''.

     NoHostAuthenticationForLocalhost
             This option can be used if the home directory is shared across
             machines.  In this case localhost will refer to a different
             machine on each of the machines and the user will get many warnM--
             ings about changed host keys.  However, this option disables host
             authentication for localhost.  The argument to this keyword must
             be ``yes'' or ``no''.  The default is to check the host key for
             localhost.

     NumberOfPasswordPrompts
             Specifies the number of password prompts before giving up.  The
             argument to this keyword must be an integer.  Default is 3.

     PasswordAuthentication
             Specifies whether to use password authentication.  The argument
             to this keyword must be ``yes'' or ``no''.  The default is
             ``yes''.

     Port    Specifies the port number to connect on the remote host.  Default
             is 22.

     PreferredAuthentications
             Specifies the order in which the client should try protocol 2
             authentication methods. This allows a client to prefer one method
             (e.g.  keyboard-interactive) over another method (e.g.  password)
             The default for this option is:
             ``hostbased,publickey,keyboard-interactive,password''.

     Protocol
             Specifies the protocol versions ssh should support in order of
             preference.  The possible values are ``1'' and ``2''.  Multiple
             versions must be comma-separated.  The default is ``2,1''.  This
             means that ssh tries version 2 and falls back to version 1 if
             version 2 is not available.

     ProxyCommand
             Specifies the command to use to connect to the server.  The comM--
             mand string extends to the end of the line, and is executed with
             /bin/sh.  In the command string, `%h' will be substituted by the
             host name to connect and `%p' by the port.  The command can be
             basically anything, and should read from its standard input and
             write to its standard output.  It should eventually connect an
             sshd(8) server running on some machine, or execute sshd -i someM--
             where.  Host key management will be done using the HostName of
             the host being connected (defaulting to the name typed by the
             user).  Note that CheckHostIP is not available for connects with
             a proxy command.

     PubkeyAuthentication
             Specifies whether to try public key authentication.  The argument
             to this keyword must be ``yes'' or ``no''.  The default is
             ``yes''.  This option applies to protocol version 2 only.

     RemoteForward
             Specifies that a TCP/IP 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 a port number, and the
             second must be host:port.  IPv6 addresses can be specified with
             an alternative syntax: host/port.  Multiple forwardings may be
             specified, and additional forwardings can be given on the command
             line.  Only the superuser can forward privileged ports.

     RhostsAuthentication
             Specifies whether to try rhosts based authentication.  Note that
             this declaration only affects the client side and has no effect
             whatsoever on security.  Most servers do not permit RhostsAuthenM--
             tication because it is not secure (see RhostsRSAAuthentication).
             The argument to this keyword must be ``yes'' or ``no''.  The
             default is ``no''.  This option applies to protocol version 1
             only.

     RhostsRSAAuthentication
             Specifies whether to try rhosts based authentication with RSA
             host authentication.  The argument must be ``yes'' or ``no''.
             The default is ``no''.  This option applies to protocol version 1
             only and requires ssh to be setuid root.

     RSAAuthentication
             Specifies whether to try RSA authentication.  The argument to
             this keyword must be ``yes'' or ``no''.  RSA authentication will
             only be attempted if the identity file exists, or an authenticaM--
             tion agent is running.  The default is ``yes''.  Note that this
             option applies to protocol version 1 only.

     SmartcardDevice
             Specifies which smartcard device to use. The argument to this
             keyword is the device ssh should use to communicate with a smartM--
             card used for storing the user's private RSA key. By default, no
             device is specified and smartcard support is not activated.

     StrictHostKeyChecking
             If this flag is set to ``yes'', ssh will never automatically add
             host keys to the $HOME/.ssh/known_hosts file, and refuses to conM--
             nect to hosts whose host key has changed.  This provides maximum
             protection against trojan horse attacks, however, can be annoying
             when the /etc/ssh/ssh_known_hosts file is poorly maintained, or
             connections to new hosts are frequently made.  This option forces
             the user to manually add all new hosts.  If this flag is set to
             ``no'', ssh will automatically add new host keys to the user
             known hosts files.  If this flag is set to ``ask'', new host keys
             will be added to the user known host files only after the user
             has confirmed that is what they really want to do, and ssh will
             refuse to connect to hosts whose host key has changed.  The host
             keys of known hosts will be verified automatically in all cases.
             The argument must be ``yes'', ``no'' or ``ask''.  The default is
             ``ask''.

     UsePrivilegedPort
             Specifies whether to use a privileged port for outgoing connecM--
             tions.  The argument must be ``yes'' or ``no''.  The default is
             ``no''.  Note that this option must be set to ``yes'' if
             RhostsAuthentication and RhostsRSAAuthentication authentications
             are needed with older servers.

     User    Specifies the user to log in as.  This can be useful when a difM--
             ferent user name is used on different machines.  This saves the
             trouble of having to remember to give the user name on the comM--
             mand line.

     UserKnownHostsFile
             Specifies a file to use for the user host key database instead of
             $HOME/.ssh/known_hosts.

     XAuthLocation
             Specifies the location of the xauth(1) program.  The default is
             /usr/X11R6/bin/xauth.

FILES
     $HOME/.ssh/config
             This is the per-user configuration file.  The format of this file
             is described above.  This file is used by the ssh client.  This
             file does not usually contain any sensitive information, but the
             recommended permissions are read/write for the user, and not
             accessible by others.

     /etc/ssh/ssh_config
             Systemwide configuration file.  This file provides defaults for
             those values that are not specified in the user's configuration
             file, and for those users who do not have a configuration file.
             This file must be world-readable.

AUTHORS
     OpenSSH is a derivative of the original and free ssh 1.2.12 release by
     Tatu Ylonen.  Aaron Campbell, Bob Beck, Markus Friedl, Niels Provos, Theo
     de Raadt and Dug Song removed many bugs, re-added newer features and creM--
     ated OpenSSH.  Markus Friedl contributed the support for SSH protocol
     versions 1.5 and 2.0.

SEE ALSO
     ssh(1)

BSD                           September 25, 1999                           BSD