Recommended Study Resources
The instructor-led classroom resource for this exam is the Securing Networks with Cisco Routers and Switches course.
For self-study, you should read the CCNP Security Secure 642-637 Official Certification Guide. This resource does a thorough job of covering the security features listed in the official exam topic list. The book also provides quizzes, memory tables, key topic lists, and practice questions on a CD-ROM.