startslip - Configures SLIP connections
/usr/sbin/startslip [-i filename]
Specifies the file containing the startslip subcommands
for dial-out connections.
The startslip program configures two types of SLIP connections:
Dial-in connections -- The system is to answer
calls from remote systems. Dial-out connections -- The
system is to place calls to a remote system.
Dial-in Connections [Toc] [Back]
If your system is configured as a dial-in system, a getty
process is continuously run on the serial line that is
connected to a modem. When a call comes in, getty prompts
for a login name. If the login name matches a SLIP user
name entry in the /etc/passwd file, getty starts startslip
as a login shell. The startslip program then reads the
/etc/slhosts files until it finds an entry matching the
current login name. If an entry is found, startslip configures
the tty line as a SLIP link using information in
the slhosts file entry.
See Network Administration: Connections for information on
setting up your system as a SLIP dial-in system.
Dial-out Connections [Toc] [Back]
If your system is configured as a dial-out system and you
want to create a SLIP connection to a remote system, you
invoke the startslip program from the command line and
specify -i filename. The filename file contains the
startslip subcommands to set up the dial-out connection
(see the Subcommands section). After making the connection,
startslip runs in the background.
When you are finished with the SLIP connection, you can
either turn off your modem or kill the tty process. The
tty process ID is stored in the /var/run/ttyxx.tel-pid
file, where ttyxx specifies the terminal line.
Subcommands [Toc] [Back]
The following startslip subcommands can be used to set up
SLIP dial-out connections. The subcommands are specified
in a SLIP setup script file that is passed to startslip
with the -i filename option. In the setup script file,
any text following the comment character (#) is ignored.
In addition, each line can contain up to 256 characters.
Specifies the callback option. If this subcommand is
specified, startslip raises Data Terminal Ready (DTR) if
carrier is lost during a read from the serial line.
Causes startslip to configure the network interface with
the values specified with the myip, dstip, and netmask
subcommands, and to attach the serial line to the network
interface. If the gateway is specified, it also adds the
destination IP address as the default gateway.
Specify this subcommand at the end of the script
file. Specify the myip, dstip, netmask, and,
optionally, gateway subcommands prior to connslip.
Enables debugging and prints debug messages to the
logfile file. Specify this subcommand at the beginning
of the script file. Dials the telephone_number.
The format of telephone_number is a string of
numbers with no separators. Specify this subcommand
after opentty and modemtype. Sets destination
IP address. You can specify either a host name or
IP address. Terminates startslip and exits.
Causes startslip to wait to receive string from the
remote host. If a match occurs, startslip continues
reading this file. If a match does not occur
after the specified seconds, startslip prints message
Specify this subcommand after opentty. Flushes the
read and write queues. Sets the destination IP
address as the default gateway. Specifies a hardwired
link. Ignore modem control signals (CLOCAL
flag set in termios structure) when switching to a
SLIP connection. Enables ICMP traffic suppression.
Sets the modem type. The modem_name specified must
be defined in the /etc/acucap file. Sets my local
IP address. You can specify either a host name or
IP address. Sets the network mask. Opens the
ttyxx serial line and sets line speed to baud_rate.
The value for baud_rate must be one of the standard
speeds listed in </usr/include/sys/termios.h>.
Prints string to the standard output; everything to
the end of the line, including punctuation, is
printed. Use this subcommand to cue the user as to
which subcommand is executing. Causes startslip to
read either the local IP address, destination IP
address, or network mask from the remote system in
dotted decimal notation. Use this subcommand after
opentty. An expect subcommand should be used prior
to raddr ensure that the desired information is
read. Sends the string to the serial line. Use
this subcommand after opentty.
If string is set to the keyword ASKPASSWD, startslip
prompts for a password, reads it from standard
input, and sends it to the serial line. Causes
startslip to sleep number_of_seconds before continuing
to read subcommands. Displays current status
of startslip. Enables TCP header compression.
Enables automatic TCP header compression.
Only a person with superuser authority can run the startslip
The following sample setup script file shows how to use
various startslip dial-out subcommands.
# set modemtype before dialing # microcom modem attributes
defined in /etc/acucap modemtype microcom
printmsg open /dev/tty00 at speed 38400 opentty tty00
printmsg dial 18154231234 dial 18154231234
# expect login prompt. timeout and exit after 5 seconds.
expect ogin: timeout 5 errmsg "not getting login: prompt"
printmsg send login send sliplogin
# expect password prompt. timeout and exit after 5 seconds.
expect assword: timeout 5 errmsg "not getting Password:
printmsg Prompt and send password send ASKPASSWD
# expect Starting SLIP after login expect SLIP timeout 10
errmsg "not getting startup message"
# connect slip - ifconfig, slattach printmsg connect slip
Specifies the command path Contains the startslip process
ID Specifies the termios header file
Files: acucap(4), slhosts(4)
Network Administration: Connections
Specifications: A Nonstandard for Transmission of IP Datagrams
Over Serial Lines: SLIP (RFC1055)
Compressing TCP/IP Headers for Low-speed Serial Links
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