.\" Copyright (c) 1986, 1991 The Regents of the University of California. .\" All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)slattach.8 6.4 (Berkeley) 3/16/91 .\" .\" $Header: /home/ncvs/src/sbin/slattach/slattach.8,v 1.11 1996/03/12 23:14:44 ache Exp $ .\" .Dd April 4, 1993 .Dt SLATTACH 8 .Os BSD 4.3 .Sh NAME .Nm slattach .Nd attach serial lines as network interfaces .Sh SYNOPSIS .Nm slattach .Op Fl a .Op Fl c .Op Fl e Ar exit-command .Op Fl f .Op Fl h .Op Fl l .Op Fl n .Op Fl z .Op Fl L .Op Fl r Ar redial-command .Op Fl s Ar baudrate .Op Fl u Ar unit-command .Op Fl K Ar keepalive .Op Fl O Ar outfill .Op Fl S Ar unit .Ar ttyname .Sh DESCRIPTION .Nm Slattach is used to assign a tty line to a network interface, and to define the network source and destination addresses. The following operands are supported by .Nm slattach : .Bl -tag -width Ar .It Fl 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. .It Fl 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. .It Fl e Ar exit-command Specifies a command to be invoked within a shell .Ql sh \-c Ar exit-command before .Nm slattach exits. .It Fl f Disables the invocation of daemon() to run .Nm slattach in the background. .It Fl h Turn on cts/rts style flow control on the slip port, by default no flow control is done. .It Fl l disable modem control (CLOCAL) and ignore carrier detect on the slip port. By default the .Ar redial-command is invoked upon carrier drop and .Nm slattach aborts if no .Ar redial-command is specified. .It Fl n Throw away ICMP packets. The slip interface will ignore ICMP packets to prevent slow lines being saturated by ICMP responses. .It Fl r Ar redial-command Specifies a command to be invoked within a shell .Ql sh \-c Ar redial-command whenever carrier is lost on the modem line. Empty .Ar redial-command i.e. .Fl r Qq "" cause connection reestablishing on leased line without any external command invoked. .It Fl s Ar baudrate Specifies the speed of the connection. If not specified, the default of 9600 is used. .It Fl u Ar unit-command When the line is switched to slip discipline, run .Ql Nm "sh -c" Ar unit-command where .Ar and .Ar 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 .Nm slattach connected first time, it run .Ql Nm "sh -c" Ar unit-command Nm \-1 Ar . When .Nm slattach disconnected, it run .Ql Nm "sh -c" Ar unit-command Nm \-1 . .Nm Slattach will abort if the unit number changes and .Ql Fl u Ar \%unit-command was not specified. .It Fl z forces redial .Ar redial-command upon startup irrespective of carrier. .It Fl L Use uucp-style device locking. You need it unless you start .Nm slattach from external program which already does uucp locking. Default case is no uucp locking to satisfy such programs. .It Fl K Ar 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. .It Fl O Ar 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. .It Fl S Ar 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. .It Ar ttyname Specifies the name of the tty device. .Ar Ttyname should be a string of the form .Ql ttyXX or .Ql /dev/ttyXX . .El .Pp Only the super-user may attach a network interface. .Pp To detach the interface, use .Dq Li ifconfig interface-name down after killing off the .Nm slattach process using .Ql kill -INT . .Ar Interface-name is the name that is shown by .Xr netstat 1 .Pp To setup .Nm slattach to redial the phone when carrier is lost, use the .Fl r Ar redial-command 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. .Pp To reconfigure the network interface in case the slip unit number changes, use the .Fl u Ar unit-command option to specify a script or executable that will be invoked as .Ql sh \-c Ar unit-command old new where .Ar old and .Ar 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 number. .Pp To kill .Nm slattach use .Ql kill -INT (SIGINT) which causes it to close the tty and exit. .Pp To force a redial, use .Ql kill -HUP (SIGHUP) which causes .Nm slattach to think carrier was lost and thus invoke .Ql sh \-c Ar redial-command to reconnect to the server. .Pp If you use a hard-wired connection rather than a modem, invoke .Nm slattach with the .Fl l option in order to ignore carrier on the slip line. .Sh EXAMPLES .Bd -literal -offset indent -compact slattach ttyd8 slattach \-s 4800 /dev/ttyd1 slattach \-c \-s 38400 /dev/cuaa1 slattach \-r 'kermit -y dial.script >kermit.log 2>&1' .Ed .Sh DIAGNOSTICS Look for error messages in /var/log/messages ( .Nm 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. .Nm 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. .Pp .Sh FILES .Pa /var/run/slattach..pid , .Pp with .Ar tty replaced by the terminal path name component of .Ar ttyname . This file contains the numerical process ID of the .Nm slattach process and can be examined by scripts in oder to send a signal to .Nm slattach . .Sh SEE ALSO .Xr netstat 1 , .Xr startslip 1 , .Xr uustat 1 , .Xr netintro 4 , .Xr ifconfig 8 , .Xr rc 8 , .Xr sliplogin 8 , /usr/share/examples/slattach .Sh HISTORY The .Nm command appeared in .Bx 4.3 .