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

     slattach -- attach	serial lines as	network	interfaces

     slattach [-a] [-c]	[-e exit-command] [-f] [-h] [-l] [-n] [-z] [-L]
	      [-r redial-command] [-s baudrate]	[-u unit-command]
	      [-K keepalive] [-O outfill] [-S unit] ttyname

     The slattach utility is used to assign a tty line to a network interface,
     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

     -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-

     -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 carrier
	     drop and slattach aborts if no redial-command is specified.

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

     -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	reestablishing
	     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 numbers
	     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 num-
	     ber changes and "-u unit-command" was not specified.

     -z	     Force redial redial-command upon startup irrespective of carrier.

     -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 default
	     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 necessary
	     for the "keep alive" timeout on the remote	side.  The default
	     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 default
	     sliplogin dynamically assigns the unit number.

	     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 recon-
     nect 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 executable
     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 disconnect at the
     same time.	 The first to succeed in reconnecting will get the lowest unit

     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.

	   slattach ttyd8
	   slattach -s 4800 /dev/ttyd1
	   slattach -c -s 38400	/dev/cuaa1
	   slattach -r 'kermit -y dial.script >kermit.log 2>&1'

     Look for error messages in	/var/log/messages (slattach is a daemon).
     Messages indicating the specified interface does not exit,	the requested
     address is	unknown, the user is not privileged and	tried to alter an in-
     terface's configuration are logged	there.	The slattach utility also logs
     failure to	set the	controlling terminal or	failure	to install signal han-
     dlers.  Upon connection and redial	the ttyname and	baud rate are logged
     and on shutdown the ttyname is logged.

     /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 examined by
				     scripts in	order to send a	signal to

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

     The slattach utility appeared in 4.3BSD.

BSD				 April 4, 1993				   BSD


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