Provided by: dropbear-bin_2017.75-3build1_amd64 bug

NAME

       dbclient - lightweight SSH client

SYNOPSIS

       dbclient  [flag  arguments]  [-p  port]  [-i  id]  [-L  l:h:p]  [-R  l:h:p] [-l user] host
       [more flags] [command]

       dbclient [args] [user1]@host1[^port1],[user2]@host2[^port2],...

DESCRIPTION

       dbclient is a small SSH client

OPTIONS

       command
              A command to run on the remote host. This will normally be run by the  remote  host
              using  the  user's shell. The command begins at the first hyphen argument after the
              host argument. If no command is specified an interactive terminal  will  be  opened
              (see -t and -T).

       -p port
              Connect  to  port  on  the  remote  host.  Alternatively a port can be specified as
              hostname^port.  Default is 22.

       -i idfile
              Identity file.  Read the identity key from file  idfile  (multiple  allowed).  This
              file   is   created   with   dropbearkey(1)   or   converted   from   OpenSSH  with
              dropbearconvert(1). The default path ~/.ssh/id_dropbear is used

       -L [listenaddress]:listenport:host:port
              Local port forwarding.  Forward the port listenport on the local host  through  the
              SSH connection to port port on the host host.

       -R [listenaddress]:listenport:host:port
              Remote port forwarding.  Forward the port listenport on the remote host through the
              SSH connection to port port on the host host.

       -l user
              Username.  Login as user on the remote host.

       -t     Allocate a PTY. This is the default when no command  is  given,  it  gives  a  full
              interactive  remote  session.  The main effect is that keystrokes are sent remotely
              immediately as opposed to local line-based editing.

       -T     Don't allocate a PTY. This is the default a command is given. See -t.

       -N     Don't request a remote shell  or  run  any  commands.  Any  command  arguments  are
              ignored.

       -f     Fork  into  the  background  after  authentication.  A  command argument (or -N) is
              required.  This is useful when using password authentication.

       -g     Allow non-local hosts to connect to forwarded ports. Applies to -L and -R forwarded
              ports,  though  remote  connections to -R forwarded ports may be limited by the ssh
              server.

       -y     Always accept hostkeys if they are  unknown.  If  a  hostkey  mismatch  occurs  the
              connection will abort as normal. If specified a second time no host key checking is
              performed at all, this is usually undesirable.

       -A     Forward agent connections to the remote host. dbclient will use  any  OpenSSH-style
              agent   program   if   available  ($SSH_AUTH_SOCK  will  be  set)  for  public  key
              authentication.  Forwarding is only enabled if -A is specified.

       -W windowsize
              Specify the per-channel receive window buffer size.  Increasing  this  may  improve
              network  performance at the expense of memory use. Use -h to see the default buffer
              size.

       -K timeout_seconds
              Ensure that traffic is transmitted at a certain interval in seconds. This is useful
              for  working  around  firewalls  or  routers  that drop connections after a certain
              period of inactivity. The trade-off is that a session may be closed if there  is  a
              temporary  lapse of network connectivity. A setting if 0 disables keepalives. If no
              response is received for 3 consecutive keepalives the connection will be closed.

       -I idle_timeout
              Disconnect the session if no traffic is transmitted or  received  for  idle_timeout
              seconds.

       -J proxy_command
              Use  the  standard  input/output  of  the program proxy_command rather than using a
              normal TCP connection. A hostname should be still be provided, as this is used  for
              comparing saved hostkeys. This command will be executed as "exec proxy_command ..."
              with the default shell.

       -B endhost:endport
              "Netcat-alike" mode, where Dropbear will connect to the given host, then  create  a
              forwarded connection to endhost. This will then be presented as dbclient's standard
              input/output.

       -c cipherlist
              Specify a comma  separated  list  of  ciphers  to  enable.  Use  -c  help  to  list
              possibilities.

       -m MAClist
              Specify  a  comma  separated  list of authentication MACs to enable. Use -m help to
              list possibilities.

       -o option
              Can be used to give options in the format used by  OpenSSH  config  file.  This  is
              useful  for  specifying  options  for which there is no separate command-line flag.
              For full details of the options  listed  below,  and  their  possible  values,  see
              ssh_config(5).

              For now following options have been implemented:

              ExitOnForwardFailure
                     Specifies  whether dbclient should terminate the connection if it cannot set
                     up all requested local and remote port forwardings.  The  argument  must  be
                     “yes” or “no”.  The default is “no”.

              UseSyslog
                     Send dbclient log messages to syslog in addition to stderr.

       -s     The  specified  command  will  be requested as a subsystem, used for sftp. Dropbear
              doesn't implement sftp itself but the OpenSSH sftp client can be used  eg  sftp  -S
              dbclient user@host

       -V     Print the version

MULTI-HOP

       Dropbear  will  also  allow  multiple "hops" to be specified, separated by commas. In this
       case a connection will be made to the first host, then a TCP forwarded connection will  be
       made  through  that  to the second host, and so on. Hosts other than the final destination
       will not see anything other than the encrypted SSH stream.  A  port  for  a  host  can  be
       specified  with  a caret (eg matt@martello^44 ).  This syntax can also be used with scp or
       rsync (specifying dbclient as the ssh/rsh  command).  A  file  can  be  "bounced"  through
       multiple SSH hops, eg

       scp -S dbclient matt@martello,root@wrt,canyons:/tmp/dump .

       Note  that  hostnames are resolved by the prior hop (so "canyons" would be resolved by the
       host "wrt") in the example above, the same way as other -L TCP forwarded hosts  are.  Host
       keys are checked locally based on the given hostname.

ESCAPE CHARACTERS

       Typing  a  newline  followed  by  the   key  sequence  ~.  (tilde,  dot)  will terminate a
       connection.  The sequence  ~^Z  (tilde,  ctrl-z)  will  background  the  connection.  This
       behaviour only applies when a PTY is used.

ENVIRONMENT

       DROPBEAR_PASSWORD
              A  password  to  use  for remote authentication can be specified in the environment
              variable DROPBEAR_PASSWORD. Care should be taken that the password is  not  exposed
              to other users on a multi-user system, or stored in accessible files.

       SSH_ASKPASS
              dbclient  can  use  an  external  program  to  request  a  password  from  a  user.
              SSH_ASKPASS should be set to the path of a program that will return a  password  on
              standard  output.  This  program  will  only  be  used if either DISPLAY is set and
              standard input is not a TTY, or the environment variable SSH_ASKPASS_ALWAYS is set.

NOTES

       If compiled with zlib support and if the server supports  it,  dbclient  will  always  use
       compression.

AUTHOR

       Matt Johnston (matt@ucc.asn.au).
       Mihnea Stoenescu wrote initial Dropbear client support
       Gerrit Pape (pape@smarden.org) wrote this manual page.

SEE ALSO

       dropbear(8), dropbearkey(1)

       https://matt.ucc.asn.au/dropbear/dropbear.html

                                                                                      dbclient(1)