I installed CentOS, but it didn't automatically connect to the internet. Is that the normal behavior? I have Ethernet Broadband Router DI-604 and WebStar DPX2203 series Cablemodem with EMTA . What should I do to connect to the internet?

Update:

A cousin told me my ethernet adapter or network board will depend on my motherboard. My computer upgrade document says the motherboard is gigabyte video onboard. I heard gigabyte's network adapters are Gigabit or Realtek.

In CentOS, System -> Administration -> Network -> New -> Ethernet, first, only "Other Network Board" was listed, so I selected it and clicked Next, then there wasn't Gigabit, but there was Realtek, so I selected Realtek.

I heard with Net Virtua selecting dhcp the things first answered asked me to tell first answerer are automatically configured.

So I tried Realtek with dhcp, but it still didn't work.