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NAME

       ser2net - Serial to network proxy

SYNOPSIS

       ser2net [-c configfile] [-C configline] [-p controlport] [-n] [-d] [-b]
       [-v] [-P pidfile]

DESCRIPTION

       The ser2net daemon allows telnet and tcp  sessions  to  be  established
       with a unit’s serial ports.

       The  program  comes  up  normally  as  a  daemon,  opens  the TCP ports
       specified in the configuration file, and waits for connections.  Once a
       connection  occurs,  the  program attempts to set up the connection and
       open the serial port.  If another user is already using the  connection
       or serial port, the connection is refused with an error message.

OPTIONS

       -c config-file
              Set  the  configuration  file  to  one other than the default of
              /etc/ser2net.conf

       -C config-line
              Handle a single  configuration  line.   This  may  be  specified
              multiple  times for multiple lines.  This is just like a line in
              the config file.  This disables the  default  config  file,  you
              must  specify  a  -c  after the last -C to have it read a config
              file, too.

       -n     Stops  the  daemon  from   forking   and   detaching   from  the
              controlling terminal. This is useful for running from init.

       -d     Like -n, but also sends the system logs to standard output. This
              is most useful for debugging purposes.

       -P pidfile
              If specified, put  the  process  id  (pid)  of  ser2net  in  the
              pidfile,  replacing  whatever  was  in  that file previously.  A
              pidfile is not created by default,  you  must  specify  this  to
              create  one.  Note also that this filename must be specific with
              the full path, as ser2net will change directory to "/"  when  it
              becomes a daemon.  when it

       -u     If  UUCP  locking  is enabled, this will disable the use of UUCP
              locks.

       -b     Cisco IOS uses a different mechanism  for  specifying  the  baud
              rates than the mechanism described in RFC2217.  This option sets
              the IOS version of setting  the  baud  rates.   The  default  is
              RFC2217’s.

       -v     Prints the version of the program and exits.

       -p controlport
              Enables  the control port and sets the TCP port to listen to for
              the control port.  A port number may be of the form [host,]port,
              such as 127.0.0.1,2000 or localhost,2000.  If this is specified,
              it will only bind to the IP  address  specified  for  the  port.
              Otherwise, it will bind to all the addresses on the machine.

              If the port number is zero, that means that standard in/out will
              be used for the only input/output, and only one port  should  be
              specified in the config.  This way, it can be used from inetd.

CONTROL PORT

       The  control port provides a simple interface for controlling the ports
       and viewing their status. To accomplish  this,  it  has  the  following
       commands:

       showport [<TCP port>]
              Show  information  about  a port. If no port is given, all ports
              are displayed.

       showshortport [<TCP port>]
              Show information about a port, each port on one line. If no port
              is  given,  all ports are displayed.  This can produce very wide
              output.

       help   Display a short list and summary of commands.

       exit   Disconnect from the control port.

       version
              Display the version of this program.

       monitor <type> <tcp port>
              Display all the input for a given port on  the  calling  control
              port.   Only one direction may be monitored at a time.  The type
              field may be tcp or term and specifies whether to  monitor  data
              from  the  TCP  port  or  from  the  serial  port Note that data
              monitoring is best effort, if the controller port cannot keep up
              the  data  will  be  silently  dropped.   A  controller may only
              monitor one thing and a  port  may  only  be  monitored  by  one
              controller.

       monitor stop
              Stop the current monitor.

       disconnect <tcp port>
              Disconnect the tcp connection on the port.

       setporttimeout <tcp port> <timeout>
              Set  the  amount  of  time in seconds before the port connection
              will be shut down if no activity has been seen on the port.

       setportconfig <tcp port> <config>
              Set the port configuration as in the device configuration in the
              /etc/ser2net.conf  file.   If conflicting options are specified,
              the last option will be the one used.  Note that these will  not
              change  until  the  port  is  disconnected  and connected again.
              Options 300, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200
              set  the  various  baud  rates.  EVEN, ODD, NONE set the parity.
              1STOPBIT, 2STOPBITS set the number  of  stop  bits.   7DATABITS,
              8DATABITS  set  the number of data bits.  [-]XONXOFF turns on (-
              off) XON/XOFF support.  [-]RTSCTS turns on (- off) hardware flow
              control.   [-]LOCAL  ignores  (- checks) the modem control lines
              (DCD, DTR, etc.)

       setportcontrol <tcp port> <controls>
              Modify  dynamic  port  controls.   These  do  not  stay  between
              connections.   Controls  are:  DTRHI, DTRLO Turns on and off the
              DTR line.  RTSHI, RTSLO Turns on and off the RTS line.

       setportenable <tcp port> <enable state>
              Sets the port operation state.  Valid states are:  off  to  shut
              the  TCP  port down, raw to enable the TCP port transfer all I/O
              as-is, rawlp to enable the TCP  port  input  and  device  output
              without termios setting, and telnet to enable the TCP port is up
              run the telnet negotiation protocol on the port.

CONFIGURATION

       Configuration is accomplished through the  file  /etc/ser2net.conf.   A
       file with another name or path may be specified using the -c option, or
       individual config lines may be specified  with  the  -C  option.   This
       file consists of one or more entries with the following format:

              <TCP port>:<state>:<timeout>:<device>:<options>

       or

              BANNER:<banner name>:<banner text>

   FIELDS
       TCP port
              Name   or  number  of the TCP/IP port to accept connections from
              for this device.  A port number may be of the form  [host,]port,
              such as 127.0.0.1,2000 or localhost,2000.  If this is specified,
              it will only bind to the IP  address  specified  for  the  port.
              Otherwise, it will bind to all the ports on the machine.

       state  Either  raw  or  rawlp  or telnet or off.  off disables the port
              from accepting connections.  It can be turned on later from  the
              control port.  raw enables the port and transfers all data as-is
              between the port and the  long.   rawlp  enables  the  port  and
              transfers  all  input data to device, device is open without any
              termios setting. It allow to use /dev/lpX devices  and  printers
              connected  to them.  telnet enables the port and runs the telnet
              protocol on the port to set up telnet parameters.  This is  most
              useful for using telnet.

       timeout
              The  time  (in  seconds) before the port will be disconnected if
              there is  no  activity  on  it.   A  zero  value  disables  this
              funciton.

       device The   name   of  the  device  to connect to. This must be in the
              form of /dev/<device>.

       device configuration options
              Sets operational parameters for the serial port.  Values may  be
              separated  by  spaces or commas.  Options 300, 1200, 2400, 4800,
              9600, 19200, 38400, 57600, 115200 set the  various  baud  rates.
              EVEN,  ODD,  NONE  set  the parity.  1STOPBIT, 2STOPBITS set the
              number of stop bits.  7DATABITS, 8DATABITS  set  the  number  of
              data  bits.   [-]XONXOFF  turns  on  (-  off)  XON/XOFF support.
              [-]RTSCTS turns on (-  off)  hardware  flow  control.   [-]LOCAL
              ignores  (-  checks)  the  modem  control lines (DCD, DTR, etc.)
              [-]HANGUP_WHEN_DONE lowers (- does not lower) the modem  control
              lines  (DCD,  DTR,  etc.)  when  the connection closes.  NOBREAK
              Disables automatic clearing of the break setting  of  the  port.
              remctl  allows  remote control of the serial port parameters via
              RFC 2217.  See the README for more info.  <banner name> displays
              the given banner when a user connects to the port.

       banner name
              A  name  for  the  banner;  this may be used in the options of a
              port.

       banner text
              The text to display as the banner.  This may contain normal  "C"
              escape strings, and it may also contain, \d for the device name,
              \p for  the  TCP  port  number,  and  \s  for  the  serial  port
              parameters (eg 9600N81) of the given connection.

       Blank lines and lines starting with ‘#’ are ignored.

SECURITY

       ser2net  uses  the  tcp  wrappers  interface  to  implement  host-based
       security.  See hosts_access(5) for a description  of  the  file  setup.
       Two  daemons  are  used by ser2net, "ser2net" is for the data ports and
       "ser2net-control" is for the control ports.

SIGNALS

       SIGHUP
            If ser2net receives a SIGHUP, it will reread it configuration file
            and  make the appropriate changes.  If an inuse port is changed or
            deleted, the actual change  will  not  occur  until  the  port  is
            disconnected.

Error

       Almost all error output goes to syslog, not standard output.

FILES

       /etc/ser2net.conf

SEE ALSO

       telnet(1), hosts_access(5)

KNOWN PROBLEMS

       None.

AUTHOR

       Corey Minyard <minyard@acm.org>