Your CCNA/CCNP home lab can benefit greatly from a 2520 router. Chris Bryant, CCIE #12933, can tell you all about the 2520.
I've put together my own CCNA/CCNP home lab, so I know how exciting and nerve-wracking it can be to decide what to buy. Cisco routers and switches can be put together in almost any way to make a home lab that works, but some routers are better for home lab work than others because they can do more than one thing.
The Cisco 2520 is the one I like best. This router is a great frame relay switch because it has four serial ports. Don't forget that you can still use a router's routing features even if you're using it as a frame switch. I use three of the four serial interfaces for frame switching and the fourth as a point-to-point network with another router. You just need DTE/DCE cables, and you're good to go.
The 2520 also comes with an ethernet interface and an ISDN interface, giving you even more choices. Even if you don't plan to use ISDN in your home lab right now, you might in the future. With a 2520, you already have the right router to do so. Remember that if you want to use ISDN in your home lab, you'll need an ISDN device like an ISDN simulator. ("Router simulators" have nothing to do with "ISDN simulators," which are real devices you can buy on eBay.)
I want to say again that you can use any Cisco router in a CCNA or CCNP home lab. There is no "right" or "wrong" way to put together the equipment. But, just like with anything else, some combinations are better than others, so you might want to add some 2520s to your home lab. This router gives you a great mix of interfaces and features, as well as the most important thing of all: real-world experience as you prepare for the CCNA and CCNP exams.
