# Static Networking Configuration

## Creating the Static Network Interface Configuration Files

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 ch-network-dhcp.