12.7. Static Networking Configuration
12.7.1. 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 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.
![[Note]](../images/note.png)
Note
Udev may assign random Network Card Interface names for some
network cards such as enp2s1. If you are not sure what your
Network Card Interface name is, you can always run ip l after you have booted your
system. Again, it is important that ifconfig.xyz is named after correct Network
Card Interface name (e.g. ifconfig.enp2s1 or ifconfig.eth0) or systemd will fail to bring up
your network interface.
The following command creates a sample ipv4 file for the eth0 device:
mkdir -pv /etc/sysconfig &&
cd /etc/sysconfig &&
cat > ifconfig.eth0 << "EOF"
IFACE="eth0"
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.
The IFACE variable defines the interface
name, for example, eth0. It is required for all network device
configuration files.
The SERVICE variable defines the method
used for obtaining the IP address. The CLFS-Network-Scripts package
has a modular IP assignment format, and creating additional files
in the /lib/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.
For more information see the ifup man page.
To configure another DHCP Interface, Follow Section 12.8, “DHCPCD-6.11.5”.
12.7.2. Configuring the Network Interface at boot
Enabling of the Network Interface configuration is done per interface. To enable Network Interface configuration at boot, run:
systemctl enable ifupdown@eth0
To disable previously enabled Network Interface configuration at boot, run:
systemctl disable ifupdown@eth0
To manually start the Network Interface configuration, run:
systemctl start ifupdown@eth0
Replace eth0 with the correct Network Interface name as described on the beginning of this page.