We get many CCNA students who ask us how to incorporate their Linksys/D-Link or similar Cable/DSL wireless router into their newly purchased Cisco CCNA lab. Although this can be done, it is not something we suggest.
The Cisco CCNP lab is one of the most difficult labs to build because it touches on so many different pieces of equipment. When you are building your Cisco CCNA lab, it is pretty easy as three Cisco router and three Cisco switches will put you in a pretty good position at a pretty reasonable price. Definitely a lot less then the price of attending a Cisco CCNA training class and you get to keep the equipment to practice on for as long as you like. When building a Cisco CCIE lab, you concentrate on one particular discipline such as CCIE Security, Voice, Service Provider, Storage or Routing and Switching so you only have to purchase Cisco equipment for that area of expertise.