Studying for the CCDP exam has been a great experience, and I’ve been exposed to so much great information through the FLG textbook. This book definitely helped to explain several technologies that I have heard about and have had vague ideas about up to this point, such as the various internals (and externals) of both service provider networks and Cisco-designed data centers.
I’ve also learned about some design aspects of enterprise campus networks that were not really covered in the ROUTE and SWITCH materials, such as making sure that only your core layer is in OSPF area 0 when possible, and to use totally stubby areas when possible to help speed convergence in large topologies. The ROUTE exam, for instance, completely covers the configuration of multi-area OSPF, but it really doesn’t go into any sort of depth as to why you would want to configure things a certain way.
Another thing I found interesting is that while the SWITCH exam covers SSO and NSF basic configuration, I didn’t feel like it explained very well that SSO is for L2 and NSF is for L3. Also from SWITCH I got the impression that this was a core layer technology, but the CCDP makes it very clear that this technology serves the access layer best. The concept of oversubscription was not covered on SWITCH at all either, but is definitely a good consideration and is explained well on CCDP.
I found the section on data center design to be thoroughly fascinating. One of the subsections I thought was great was the idea of supporting 1,000 servers in a data center using a Top of Rack vs. End of Row switching design. I think this might be the first time I’ve been given a look into how a large data center would actually be cabled for network connectivity and it gave me some new ideas to consider. The FLG gives the hypothetical of supporting 1,000 servers via 80 TOR switches, or 8 larger EOR switches, and the differences in cabling each. And of course the (expensive) best of both worlds with the Nexus 5000 + 2000 FEXs.
Probably one fourth of the book covered various aspects of security. At this point in time, I’ve had a basic-level understanding of security. I understand the theory behind most general types of attacks, and the purpose and positioning of firewalls. I’ve even implemented CBAC-based firewalls in Cisco routers. However, there is definitely a much deeper level of knowledge available out there and studying for the CCDP has made me consider at least reviewing the materials for the Cisco security exams, even if I don’t actually pursue the certifications.
There is a lot of information within this book, and while it certainly goes much deeper than the CCDA material, it still makes me wonder just how difficult it is to pass the CCDE. With the CCDP, experience will definitely help (as with any Cisco exam), but it is definitely going to be passable without having much actual enterprise-level experience. However, I don’t believe the CCDE is the same way 🙂