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SLATTACH(8)		    System Manager's Manual		   SLATTACH(8)

NAME
       slattach	-- attach serial lines as network interfaces

SYNOPSIS
       slattach	 [-acfhLlnz]  [-e  exit-command]  [-K  keepalive] [-O outfill]
		[-r redial-command] [-S	unit] [-s baudrate] [-u	 unit-command]
		ttyname

DESCRIPTION
       The  slattach  utility is used to assign	a tty line to a	network	inter-
       face, and to define the network source and destination addresses.

       The following options are available:

       -a      Autoenable the VJ header	compression option, if the  other  end
	       of the link is capable of VJ header compression then it will be
	       used otherwise normal headers will be used.

       -c      Enable  the  VJ header compression option.  Note	that both ends
	       of the link must	be able	to use VJ header compression for  this
	       to work.

       -e exit-command
	       Specify	a  command  to	be  invoked  within  a	shell  `sh  -c
	       exit-command' before slattach exits.

       -f      Disable the invocation of daemon() to run slattach in the back-
	       ground.

       -h      Turn on cts/rts style flow control on the slip port, by default
	       no flow control is done.

       -l      Disable modem control (CLOCAL) and ignore carrier detect	on the
	       slip port.  By default the redial-command is invoked upon  car-
	       rier  drop  and	slattach aborts	if no redial-command is	speci-
	       fied.

       -n      Throw away ICMP packets.	 The slip interface will  ignore  ICMP
	       packets	to  prevent  slow  lines  being	 saturated by ICMP re-
	       sponses.

       -r redial-command
	       Specify	a  command  to	be  invoked  within  a	shell  `sh  -c
	       redial-command'	whenever  carrier  is  lost on the modem line.
	       Empty redial-command (i.e. -r "") cause connection reestablish-
	       ing on leased line without any external command invoked.

       -s baudrate
	       Specify the speed of the	connection.  If	not specified, the de-
	       fault of	9600 is	used.

       -u unit-command
	       When the	line is	 switched  to  slip  discipline,  run  "sh  -c
	       unit-command  old new" where old	and new	are the	slip unit num-
	       bers when the line was last opened and the unit number  of  the
	       current	slip  connection  respectively.	  The  unit number can
	       change after redialing if you are  using	 more  than  one  slip
	       line.   When  slattach  is connected for	the first time,	"sh -c
	       unit-command -1 new" is run.  When  slattach  is	 disconnected,
	       "sh  -c unit-command old	-1" is run.  The slattach utility will
	       abort if	the unit number	changes	and "-u	unit-command" was  not
	       specified.

       -z      Force  redial  redial-command upon startup irrespective of car-
	       rier.

       -L      Use uucp-style device locking.  You need	it  unless  you	 start
	       slattach	from external program which already does uucp locking.
	       Default case is no uucp locking to satisfy such programs.

       -K keepalive
	       Set  SLIP "keep alive" timeout in seconds.  If FRAME_END	is not
	       received	in this	amount of time,	re-connect  occurs.   The  de-
	       fault value is no timeout.

       -O outfill
	       Set SLIP	"out fill" timeout in seconds.	It forces at least one
	       FRAME_END  to  be sent during this time period, which is	neces-
	       sary for	the "keep alive" timeout on the	remote side.  The  de-
	       fault value is no timeout.

       -S unit
	       Set  the	 SLIP unit number directly.  Use with caution, because
	       no check	is made	for two	interfaces with	same number.   By  de-
	       fault sliplogin dynamically assigns the unit number.

       ttyname
	       Specify the name	of the tty device.  Ttyname should be a	string
	       of the form `ttyXX' or `/dev/ttyXX'.

       Only the	super-user may attach a	network	interface.

       To  detach  the	interface,  use	 "ifconfig  interface-name down" after
       killing off the slattach	process	using `kill -INT'.  Interface-name  is
       the name	that is	shown by netstat(1).

       To  setup slattach to redial the	phone when carrier is lost, use	the -r
       redial-command option to	specify	a script or executable that  will  re-
       connect	the  serial  line to the slip server.  For example, the	script
       could redial the	server and log in, etc.

       To reconfigure the network interface  in	 case  the  slip  unit	number
       changes,	 use  the  -u  unit-command option to specify a	script or exe-
       cutable that will be invoked as `sh -c unit-command old new' where  old
       and  new	 are  the  slip	unit numbers before and	after reconnecting the
       line.  The unit number can change if you	have more than one  line  dis-
       connect	at  the	 same time.  The first to succeed in reconnecting will
       get the lowest unit number.

       To kill slattach	use `kill -INT'	(SIGINT) which causes it to close  the
       tty and exit.

       To  force  a  redial, use `kill -HUP' (SIGHUP) which causes slattach to
       think carrier was lost and thus invoke `sh -c redial-command' to	recon-
       nect to the server.

       If you use a hard-wired connection rather than a	modem, invoke slattach
       with the	-l option in order to ignore carrier on	the slip line.

FILES
       /var/run/slattach.<tty>.pid     with tty	replaced by the	terminal  path
				       name  component	of ttyname.  This file
				       contains	the numerical  process	ID  of
				       the  slattach  process and can be exam-
				       ined by scripts in order	to send	a sig-
				       nal to slattach
       /usr/share/examples/slattach/*

EXAMPLES
	     slattach ttyd8
	     slattach -s 4800 /dev/ttyd1
	     slattach -c -s 38400 /dev/cuad1
	     slattach -r 'kermit -y dial.script	>kermit.log 2>&1'

DIAGNOSTICS
       Look for	error messages in /var/log/messages (slattach  is  a  daemon).
       Messages	 indicating  the  specified  interface	does not exit, the re-
       quested address is unknown, the user is not privileged and tried	to al-
       ter an interface's configuration	are logged there.  The slattach	 util-
       ity also	logs failure to	set the	controlling terminal or	failure	to in-
       stall signal handlers.  Upon connection and redial the ttyname and baud
       rate are	logged and on shutdown the ttyname is logged.

SEE ALSO
       netstat(1), startslip(1), netintro(4), ifconfig(8), rc(8), sliplogin(8)

HISTORY
       The slattach utility appeared in	4.3BSD.

FreeBSD	7.4			 April 4, 1993			   SLATTACH(8)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=slip&sektion=8&manpath=FreeBSD+7.4-RELEASE>

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