The preferred way of setting up your network connection is through the use of the netconfig program. Run this as root and you will be presented with a series of questions to answer. The program will then edit the rc.inet1.conf 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.conf and /etc/rc.d/rc.inet2 , which are discussed in greater detail below.
The netconfig program will ask if you want to use DHCP for your network setup. Or you can edit rc.inet1.conf to run /sbin/dhcpd for you. Be sure that you have kernel support for your network card enabled (netconfig can do this for you).
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, reading config options from its config file: rc.inet1.conf.
This configuration file is pretty simple, it supports up to 3 different networking devices. For each device there’s a section like the following:
# Config information for eth0:
Your IP address (IPADDR) you can get from your network administrator. The netmask is almost always going to be 255.255.255.0, unless your machine is at the top of the subnet (in which case you probably don’t need this page). USE_DHCP and DHCP_HOSTNAME are used if you lease an IP address from a DHCP server.
At the bottom of rc.inet1.conf you’ll find:
# Default gateway IP address:
# Change this to “yes” for debugging output to stdout. Unfortunately,
# /sbin/hotplug seems to disable stdout so you’ll only see debugging output
# when rc.inet1 is called directly.
GATEWAY is usually going to be the first machine on your subnet (though it may not be… ask your network admin.). DEBUG_ETH_UP can be used for debugging purposes.
rc.inet1 gives you a network; rc.inet2 finishes the job of network configuration by running stuff on that network. Any services or daemons that use the network should be started from this file. Most of the rc scripts in charge of starting daemons like inetd, sshd, bind, nfs, etc get called from rc.inet2.
Other daemons (httpd, mysql, samba, etc) get called by init scripts run from rc.M, so that’s where you may want to look at, if you need to disable them (or see how it works 😉