CCDA (Cisco Certified Design Associate) certification is a compliment to the CCNA.
It is another entry level, single test certification.
Where the CCNA concentrates on how to configure and manage routers and switches,
CCDA concentrates on designing the network.
Be prepared for fewer what to do questions and more of the why you should do it variety.
To earn this certification you must pass the
Designing for Cisco Internetwork Solutions Exam (DESGN 640-861).
There is a definite lack of materials for CCDA study when compared to the CCNA.
This is probably because the CCDA is not nearly as popular.
It is unforunate being that a poorly designed network can haunt those who must
manage it for years to come.