How it works...

All we've done here is created an interface script that your system can use to correctly configure an interface at boot time.

Let's go through the options we added to our file.

BOOTPROTO=none

This setting stands for boot-time protocol and we've set it to none instead of dhcp or bootp.

In a DHCP environment, you want an address to be assigned automatically by your DHCP server. Here, we're setting a static address, so we state the following.

ONBOOT=yes

This one might seem obvious, but the default behaviour of an interface is to not initialize at boot. With this setting, we ensure that the network interface is brought up with the system.

IPADDR=192.168.44.10
NETMASK=255.255.255.0

Somewhat self-explanatory, but these options are the IP address and the subnet mask of the network we're configuring. Here, I chose another /24 network, a few octets above our eth1 configuration.

DEVICE=eth2

This option is used to specify which hardware interface our configuration will apply to. It's worth noting that these interface names can be both generic (eth0, eth1, and so on) and network card name-specific (they might not always be eth<something>).

PEERDNS=no

Defaulting to yes in a DHCP environment, this option ensures that our system doesn't try to modify /etc/resolv.conf when the interface is brought up.