I'd suggest starting with the CCNA. Nobody is going to let you design a network if you don't
have the ability to administer it (at least to a minimal extent), which is measured by the CCNA.
Once you have the CCNA, try for the CCDA and then one of the more advanced exams (switching
or routing). It's very important to try to get a junior networking job early, even if it's as a physical
layer technician. Physical layer experience is worth gold later in a career (even for managers,
who have to deal with physical-layer contractors). Some community colleges have
physical layer network technician classes, which are usually enough to get you in the door
(and, when combined with the CCNA, help you get that junior network engineer job).
I suppose the CCDA test would be better if you were trying to get a network equipment
sales job, but for network operations the CCNA (and physical layer training) are the first steps.
