Which interfaces are brought up and down by the network script
depends on the files and directories in the /etc/sysconfig/network-devices hierarchy. This
directory should contain a sub-directory for each interface to be
configured, such as ifconfig.xyz,
where “xyz” is a network
interface name. Inside this directory would be files defining the
attributes to this interface, such as its IP address(es), subnet
masks, and so forth.
The following command creates a sample ipv4 file for the eth0 device:
cd /etc/sysconfig/network-devices &&
mkdir -v ifconfig.eth0 &&
cat > ifconfig.eth0/ipv4 << "EOF"
ONBOOT="yes"
SERVICE="ipv4-static"
IP="192.168.1.1"
GATEWAY="192.168.1.2"
PREFIX="24"
BROADCAST="192.168.1.255"
EOF
The values of these variables must be changed in every file to
match the proper setup. If the ONBOOT
variable is set to “yes” the
network script will bring up the Network Interface Card (NIC)
during booting of the system. If set to anything but
“yes” the NIC will be
ignored by the network script and not be brought up.
The SERVICE variable defines the method
used for obtaining the IP address. The CLFS-Bootscripts package has
a modular IP assignment format, and creating additional files in
the /etc/sysconfig/network-devices/services directory
allows other IP assignment methods.
The GATEWAY variable should contain the
default gateway IP address, if one is present. If not, then comment
out the variable entirely.
The PREFIX variable needs to contain the
number of bits used in the subnet. Each octet in an IP address is 8
bits. If the subnet's netmask is 255.255.255.0, then it is using
the first three octets (24 bits) to specify the network number. If
the netmask is 255.255.255.240, it would be using the first 28
bits. Prefixes longer than 24 bits are commonly used by DSL and
cable-based Internet Service Providers (ISPs). In this example
(PREFIX=24), the netmask is 255.255.255.0. Adjust the PREFIX variable according to your specific subnet.
To configure another DHCP Interface, Follow Section 12.6.2, “Creating the DHCP Network Interface Configuration Files”.