need help connectings

need help connecting

I need help with this I trying to use onbaord lan that is on the motherboard, Everything works fine when it's onboard lan is connected to router, when I change so the onboard lan is connected to cable modem I get problem, my problem is that is slow, it's beyond slow it loads yahoo page for about 2 min also the ip address is different, it suppose to be somehing that strarts with 24 and it starts with 67, I don't have that problem using PCi lan network card. I installed the drive for onboard lan

Sometimes when you go from the lan jack directly to a cable modem you need a crossover cable. Have you tried that? When you go through a router it does the crossover for you.

how to do this, what is it?