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

     slattach -- attach	serial lines as	network	interfaces

     Slattach [-a] [-c]	[-e exit-command] [-f] [-h] [-l] [-n] [-r
     redial-command] [-s baudrate] [-u unit-command] [-z] ttyname

     Slattach is used to assign	a tty line to a	network	interface, and to
     define the	network	source and destination addresses.  The following oper-
     ands are supported	by slattach:

     -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		   Enables 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
		   Specifies a command to be invoked within a shell (sh	-c
		   exit-command) before	slattach exits.

     -f		   Disables the	invocation of daemon() to run slattach in the

     -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

     -r	redial-command
		   Specifies a command to be invoked within a shell (sh	-c
		   redial-command) whenever carrier is lost on the line.

     -s	baudrate   Specifies the speed of the connection. If not specified,
		   the default of 9600 is used.

     -u	unit-command
		   When	the line is switched to	slip discipline, run `sh -c
		   unit-command	<last> <current>' where	<last> and <current>
		   are the slip	unit numbers when the line was last opened and
		   the unit number of the current slip connection
		   respecitvely.  The unit number can change after redialing
		   if you are using more than one slip line.  Slattach will
		   abort if the	unit number changes and	`-u unit-command' was
		   not specified.

     -z		   forces redial redial-cmd upon startup irrespective of car-

     ttyname	   Specifies 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-cmd' option	to specify a script or executable that will reconnect
     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-cmd' option to specify a	script or executable
     that will be invoked as `sh -c unit-cmd 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 num-

     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 ttyh8
	   slattach -s 4800 /dev/tty01
	   slattach -c -s 38400	/dev/sio01
	   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
     interface's configuration are logged there.  Slattach also	logs failure
     to	set the	controlling terminal or	failure	to install signal handlers.
     Upon connection and redial	the ttyname and	baud rate are logged and on
     shutdown the ttyname is logged.

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

     The slattach command appeared in 4.3BSD.

4.3 Berkeley Distribution	 April 4, 1993	     4.3 Berkeley Distribution


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