Creating the /etc/init.d/ethnet script

This section only applies if a user is going to configure a network card. If not, this section can be skipped.

A new file /etc/init.d/ethnet is created containing the following:



cat > /etc/init.d/ethnet << "EOF"
#!/bin/sh
# Begin /etc/init.d/ethnet
#
# Main script by Gerard Beekmans - [email protected]
# GATEWAY check by Jean-Fran´┐Żois Le Ray - [email protected]
#

#
# Include the functions declared in the /etc/init.d/functions file
# and the variables from the /etc/sysconfig/network file.
#

source /etc/init.d/functions
source /etc/sysconfig/network

case "$1" in
        start)

#
# Obtain all the network card configuration files
#

        for interface in $(ls /etc/sysconfig/network-scripts/ifcfg* | \
            grep -v ifcfg-lo)
        do
#
# Load the variables from that file
#

            source $interface
#
# If the ONBOOT variable is set to yes, process this file and bring the
# interface up.
#

            if [ "$ONBOOT" == yes ]
            then
                echo -n "Bringing up the $DEVICE interface..."
                /sbin/ifconfig $DEVICE $IP broadcast $BROADCAST \
                    netmask $NETMASK
                evaluate_retval
            fi
        done

#
# If the /etc/sysconfig/network file contains a GATEWAY variable, set
# the gateway.
#

            if [ "$GATEWAY" != "" ]; then
                echo -n "Setting up routing for eth0 interface..."
                /sbin/route add default gw $GATEWAY metric 1
                evaluate_retval
            fi
                ;;

        stop)

#
# Obtain all the network card configuration files
#

        for interface in $(ls /etc/sysconfig/network-scripts/ifcfg* | \
            grep -v ifcfg-lo)
        do
#
# Load the variables from that file
#

            source $interface
#
# If the ONBOOT variable is set, process the file and bring the
# interface down
#

            if [ $ONBOOT == yes ]
            then
                echo -n "Bringing down the $DEVICE interface..."
                /sbin/ifconfig $DEVICE down
                evaluate_retval
            fi
        done
                ;;

        restart)
                $0 stop
                sleep 1
                $0 start
                ;;
        *)
                echo "Usage: $0 {start|stop|restart}"
                exit 1
                ;;
esac

# End /etc/init.d/ethnet
EOF

Adding default gateway to /etc/sysconfig/network

If a default gateway is required to be setup, the following command does that:



cat >> /etc/sysconfig/network << "EOF"
GATEWAY=192.168.1.2
EOF

GATEWAY needs to be changed to match the network setup.

Creating NIC configuration files

Which interfaces are brought up and down by the ethnet script depends on the files in the /etc/sysconfig/network-scripts directory. This directory should contain files in the form of ifcfg-x where x is an identification number (or whatever a user named it).

First the network-scripts directory is created by running:



mkdir /etc/sysconfig/network-scripts

Now, new files are created in that directory containing the following. This creates a sample file ifcfg-eth0:



cat > /etc/sysconfig/network-scripts/ifcfg-eth0 << EOF
ONBOOT=yes
DEVICE=eth0
IP=192.168.1.1
NETMASK=255.255.255.0
BROADCAST=192.168.1.255
EOF

Of course, the values of those four variables have to be changed in every file to match the proper setup. Usually NETMASK and BROADCAST will remain the same, just the DEVICE IP variables will change per network interface. If the ONBOOT variable is set to yes, the ethnet script will bring it up during boot up of the system. If set to anything else but yes it will be ignored by the ethnet script and thus not brought up.

Setting up permissions and symlink

The proper file permissions and the necessary symlinks are set or created by running the following commands:



cd /etc/init.d &&
chmod 754 ethnet &&
cd ../rc3.d &&
ln -s ../init.d/ethnet S200ethnet &&
cd ../rc4.d &&
ln -s ../init.d/ethnet S200ethnet &&
cd ../rc5.d &&
ln -s ../init.d/ethnet S200ethnet