Before you try to configure your system to access a network via Ethernet, you must have basic IP address information. If your network offers Dynamic Host Configuration Protocol (DHCP) and your machine is a client, you can just use that and connect to the network as another client. If this machine will be a server, a static IP address is more sensible. Each server requires:
An IP address
The netmask for that IP address
The IP address of the default gateway
Armed with this information, attach your system to the network with ifconfig(8) and route(8).
The ifconfig(8) program displays the interfaces on your computer and lets you configure them. Start by listing the existing interfaces on your system by running ...