Provided by: dropbear_2013.60-1ubuntu2_amd64 bug


       dbclient - lightweight SSH client


       dbclient [-Tt] [-p port] [-i id] [-L l:h:r] [-R l:h:r] [-l user] host [command]

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


       dbclient  is  a  SSH  client  designed  to  be  small  enough  to  be used in small memory
       environments, while still being functional and secure enough for general use.

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


       -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

       -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.

       -T     Don't allocate a PTY.

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

       -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

       -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

       -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.

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

       -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.

       -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

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

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

       -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


       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 hash (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.


       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.


              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.

              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.


       Matt Johnston (
       Mihnea Stoenescu wrote initial Dropbear client support
       Gerrit Pape ( wrote this manual page.


       dropbear(8), dropbearkey(1)