Ethernet Setup (can there be two?)

I want occasionally to use my laptop hooked up to a LAN and occasionally to a DSL line. As I understand it, I will have to use a different set up for the ethernet card for the former from that which I will use for the latter hook-up. My questions: Can I set up the same ethernet card with two sets of parameters, selecting the appropriate one for each hook-up? If I can't, how should I go about using the laptop with both? thanks -- dj tuchler dtuchler@earthlink.net