Setting up a PPP connection to your ISP

Basic setup.

As a start, your kernel must have ppp support, and you must have a pppd that isn't too old. Try to execute the command 'pppd' at a root prompt, you should get a lot of funny characters, not the message "This kernel lacks kernel support". I you get the message, something is wrong ! =)

By the way, the funny characters stops after a short while, just be patient.

Files.

Start by creating an empty file named /etc/ppp/options. This can be done by executing :> /etc/ppp/options at a root prompt. Make a symlink named /dev/modem to the com port your modem is placed at, that is /dev/ttyS0 if your modem sits on COM1, /dev/ttyS1 if it's connected to COM2.. Do this by executing # ln -s /dev/ttyS0 /dev/modem . First, make sure the link doesn't exist, your distribution may have done that work at installation.

#!/bin/sh

# PPP-script made by Simon Josefsson <jas@pdc.kth.se>.

tmpfile=/tmp/ppp.script.$$
source /etc/ppp/provider
export TELEPHONE LOGIN LOGINSTR PASSWORD PASSWORDSTR PPPCOMMANDSTR PPPCOMMAND

if test -n "$USEPAP"; then
        PAP="name $PAPLOGIN remotename $USEPAP"
fi

umask 0177
cat<<EOF>$tmpfile
TIMEOUT         5
ABORT           BUSY
ABORT           "NO DIAL TONE"
ABORT           \nRINGING\r\n\r\nRINGING\r
ABORT           "NO CARRIER"
""              \r\rATZ
OK-+++\c-OK     ATH0
TIMEOUT         60
OK              ATDT$TELEPHONE
CONNECT         \n
TIMEOUT         40
$LOGINSTR       $LOGIN
$PASSWORDSTR    $PASSWORD
$PPPCOMMANDSTR  $PPPCOMMAND
EOF

exec /usr/sbin/pppd -detach debug lock modem crtscts /dev/modem 57600 \
        noipdefault netmask 255.255.255.0 defaultroute $PAP \
        connect "/usr/sbin/chat -v -f $tmpfile" disconnect "rm -f $tmpfile" &

/etc/ppp/off

Save this as /etc/ppp/off (Or, get it by clicking here)

#!/bin/sh
if [ "$1" = "" ]; then
        DEVICE=ppp0
else
        DEVICE=$1
fi
if [ -r /var/run/$DEVICE.pid ]; then
        kill -INT `cat /var/run/$DEVICE.pid`
        if [ ! "$?" = "0" ]; then
                rm -f /var/run/$DEVICE.pid
                echo "ERROR: Removed stale pid file"
                exit 1
        fi
        echo "PPP link to $DEVICE terminated."
        exit 0
fi
echo "ERROR: PPP link is not active on $DEVICE"
exit 1

Nameservers, /etc/resolv.conf

If you want to be able to use the internet by typing names (like http://www.lysator.liu.se/~forsberg/) instead of numbers (like 10.38.0.18) you have to tell the linux resolver library how to get the information what number correspond to which names. This is done by writing nameserver statements to the file /etc/resolv.conf. Get ip adress of your nameserver from the information your ISP sent you, and write something like this in /etc/resolv.conf

nameserver 10.38.0.18

ISP Specific settings

Here comes the hard part :-) Now you must give pppd ISP specific settings, writing some words in /etc/ppp/provider and, if the ISP uses PAP or CHAP, a few words in /etc/ppp/pap-secrets or /etc/ppp/chap-secrets respective.

Here is a list of the statements you may use, with descriptions.

The secrets file.

If your provider uses PAP or CHAP, a line in the /etc/ppp/pap-secrets, or chap-secrets should be added. It should look like <account> <providername> <password> where account and providername is the same as you put in the /etc/ppp/provider with the PAPLOGIN and USEPAP statements.

Some examples of /etc/ppp/provider and /etc/ppp/pap-secrets

TELEPHONE=555112233
LOGINSTR=ogin:--ogin:
LOGIN=mystupidaccountname
PASSWORDSTR=assword:
PASSWORD=MyTooEasyPassword

TELEPHONE=555221133
PAPLOGIN=mystupidaccountname
USEPAP=providername

mystupidaccountname    providername   MyTooEasyPassword