CLI was used in terms of the old Amiga computer and sometimes referred to in windows.
In Unix and linux we use a terminal and our command line is called the "shell", so in future you can ask for shell commands, from the console, or from a terminal (but we all know what you mean

)
You first need to know if your network interface has been recognised so you will type
as root:
ifconfigYou will see info for loopback and hopefully the first network interface, which will be called eth0.
If for example you want to statically assign an address of 192.168.0.20 to your network card you would use
ifconfig eth0 192.168.0.20 netmask 255.255.255.0Check with ifconfig or ifconfig eth0
This would set up your NIC correctly.
Now you would have to add a default gatway, this is the address of your router,
this may be 192.168.0.1
route add default gw 192.168.0.1you can check its been set with
route -nFinally you need to set your ISP, DNS servers in /etc/resolv.conf If the DNS servers are programmed into your router then you simply point resolv.conf at your router
The contents of file /etc/resolv.conf would look like
nameserver 192.168.0.20You can check if things are working by first pinging the gateway, then a wan address
e.g.
ping -c4 192.168.0.20
ping -c4
www.google.comHope that helps.