The preferred way of setting up your network connection is through the use of the netconfig program. Run this as root and you will presented with a series of questions to answer. The program will then create the rc.inet1 file. You will also need kernel support for your network card. The netconfig program can probe your system for a network card and enable it. Or you can edit /etc/rc.d/rc.modules and select your card. You can, of course, edit the network configuration files by hand. They are /etc/rc.d/rc.inet1 and /etc/rc.d/rc.inet2, which are discussed in greater detail below.
rc.inet1's role is simple: it configures your networking devices and sets up your routing. Essentially, rc.inet1 is the file that gives you a network in the first place.
Sample of rc.inet1
# Edit for your setup.