There are lots of good classes that you might take after completing the ICND. Which one is best would depend on your background, your interests, and where you want more knowledge. In particular I would recommend either the switching course (BCMSN) is you want to learn more with an emphasis on layer 2. Or I would recommend the advanced routing (BSCI) if you want to learn more about layer 3 and routing. They are both good courses and at some point you should plan to take each of them.
HTH
Rick
HTH
Rick
