It is possible to do it in 2 months+, but iek Garv said that depends on you. It depends mainly on how much time you will spend on study each day.
There are two ways to become a CCNA:
- take the 640-801 exam
-or take the 640-811 and the 640-821
In your case, because you already have Network+, you should probably go for the one exam (640-801).
Basically, the difference is that the exam is literally broken down into two parts when you take the 2exams method. The benefit of this option is that you can work on one part of the exam at a time. The disadvantage is that you'll be paying twice the money if you pass on the first try ---and more if you don't. You’ll also have to answer double the questions on the 801 exam. Yet, the questions in the INTRO/ICND method have a more limited scope than the ones in the 801 exam.
So you better weigh all these factors before you choose which exam method you’ll take. Remember, however, that what you study and how you take the exam have no correlation whatsoever. Grab Lammle's book and by the time you're through it thoroughly, you'll be ready for any track you choose.
I'll do the 640-801 exam (well partially because I'm short on $$ and.... I want to get it over with )
p.s. If you haven't bought any books yet, make sure you buy Todd Lammle's 4th Edition CCNA Study Guide. That book rocks!