A harrowing read of an lone IPv4 packets journey through the Internet. It continually needs to make choices that will affect it's success. EIGRP or BGP? GRE tunneling or DMVPN? 3DES encryption or AES? Finally the packet arrives and has blossomed into a full fledge IPv6 packet.
Just kidding. It's a Cisco Press Technical book for goodness sake. It's just as boring as the rest of the Cisco Press books. Definitely will help you along the way to getting your Certified Cisco Network Professional (CCNP) though.
This is classic Cisco Press material. It's very detailed with minimal mistakes which can be corrected with a quick trip to their home page.
Despite being titled the "Official Certification Guide", this is a supplement at best. Passing the certification will require other material, labs, and study guides to properly prepare unless you are heavy into Cisco at work and utilize every one of the key technologies on a daily basis.
I've used this book along with INE CCNP ROUTE videos and the Cisco Quick Sheet PDF to pass the route exam. It goes in more detail the what is required for the exam but it can be very interesting if you are a Network Engineer and you want to go in deep detail on some stuff such as OSPF LSA types or complex redistributions among different protocols.