NAME

startslip − Configures SLIP connections

SYNOPSIS

/usr/sbin/startslip [-i filename]

FLAGS

-i filename
Specifies the file containing the startslip subcommands for dial-out connections. 

DESCRIPTION

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

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 for information on setting up your system as a SLIP dial-in system. 

Dial-out Connections

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

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 flag.  In the setup script file, any text following the comment character (#) is ignored.  In addition, each line can contain up to 256 characters. 

callback
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. 

connslip
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. 

debug logfile
Enables debugging and prints debug messages to the logfile file.  Specify this subcommand at the beginning of the script file. 

dial telephone_number
Dials the telephone_number.  The format of telephone_number is a string of numbers with no separators.  Specify this subcommand after opentty and modemtype. 

dstip hostname | IP address
Sets destination IP address.  You can specify either a host name or IP address.

exitTerminates startslip and exits. 

expect string timeout seconds errmsg message
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 and exits. 

Specify this subcommand after opentty. 

flushFlushes the read and write queues. 

gateway
Sets the destination IP address as the default gateway.

hardwired
Specifies a hard-wired link.  Ignore modem control signals (CLOCAL flag set in termios structure) when switching to a SLIP connection. 

icmpsup
Enables ICMP traffic suppression.

modemtype modem_name
Sets the modem type.  The modem_name specified must be defined in the /etc/acucap file. 

myip hostname | IP address
Sets my local IP address.  You can specify either a host name or IP address.

netmask
Sets the network mask.

opentty ttyxx speed baud_rate
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. 

printmsg string
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. 

raddr myip | dstip | netmask
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. 

send string
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. 

sleep number_of_seconds
Causes startslip to sleep number_of_seconds before continuing to read subcommands. 

statusDisplays current status of startslip. 

tcpcomp
Enables TCP header compression.

tcpautoEnables automatic TCP header compression. 

RESTRICTIONS

Only a person with superuser authority can run the startslip program. 

EXAMPLES

The following sample setup script file shows how to use various startslip dial-out subcommands. 

debug /tmp/debuglog
myip 27.140.208.38
dstip 27.140.208.40
netmask 255.255.255.0
# set modemtype before dialing
# microcom modem attributes defined in /etc/acucap
modemtype microcom
printmsg open /dev/tty00 at speed 38400
opentty tty00 speed 38400
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: prompt"
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
connslip

FILES

/usr/sbin/startslip
Specifies the command path

/var/run/ttyxx.tel-pid
Contains the startslip process ID

/usr/include/termios.h
Specifies the termios header file

RELATED INFORMATION

Commands: ifconfig(8). 

Files: acucap(4), slhosts(4)

Network Administration

Specifications: A Nonstandard for Transmission of IP Datagrams Over Serial Lines: SLIP (RFC1055)

Compressing TCP/IP Headers for Low-speed Serial Links (RFC1144)