If you're talking about a labtop, the ethernet port may be directly connected to the motherboard, meaning that you would have to replace the entire motherboard. I'm not entirely sure about this, so wait and I'm sure others with more experience will chime in.

Its an inspiron 8500... anybody got more information on that?

Your Ethernet port is soldered on the mainboard, there is no ethernet card that you can exchange. If you got completecare, let Dell do the fix. If you don't, you can try to repair it yourself (or let somone else do it). If that doesn't work, you'll have to get a new mainboard, which is very expensive.