I've just taken the CCDE Practical exam. The result will come only after 6-8 weeks, and frankly I don't know if I will pass or not due to the way the questions are presented. Mind you there are many questions require to drag-and-drop, fill in the table/matrix, re-ordering, and adding device/link into the existing network diagram, and in CCDE exam partial credit is possible.
For me, the content and coverage of the exam were a bit unexpected. So I wrote the following based on my own experience taking the exam today.
We Need a Very Good Stamina
- Surprisingly for the CCDE I found the time is not the main issue, 8 hours should be enough because we can't go back to the previous questions or re-check our work anyway. We just need to make sure to do each scenario within the average time allocated (if there are 10 scenarios, just divide 8 hours with 10 to get the average time we have per scenario)
- But what we really need is good stamina to be able to stay focus and concentrate after reading multiple different scenarios and hundreds of questions!
- Nice sleep and good dinner/breakfast is compulsory (in my case, lunch provided at testing center was horrible! And I was unlucky, I didn't have breakfast in the morning)
We Need to Have Broad "Design Experience"
- I believe there won't be any book or training to face this exam, the best practices design document or case studies may help
- We really need to have design experience and analytical skills, not as low level designer but more like as 'high level' solution designer
- Our experience and knowledge should cover the design for different type of customer network and industry, from ISP to Enterprise like Retail, Financial, Media etc in order to understand not only the challenges with the design of certain network type, but as well as type of the applications run and the network requirements of those applications that may affect the design decision
We Need to Understand What They Want
- Even we have extensive and broad design experience, our logic must sync with what the exam authors wanted
- Sometime there is more than one right way to solve the requirement, but we need to know which one is the expected answer based on the information provided
- Similarly, for re-ordering question, we need to make the order based on related information and which is the most correct (and for me it's still difficult to figure out the "right" order since I believe there is more than one possibility of the orders as the answer)
- CCDE Practical Exam Demo can show a brief example, the Networkers 2009 slides from Russ White can even provide closer view of the real practical exam
We Need to be Able to Relate Only the Important Information
- There are lots and lots of information provided, sometime half of the information is not important (but we still need to read and screen it at least during the first reading)
- But sometime the information can be very minimum, for example, for some application it's assumed that we know how it works
- This is the point where we need the good stamina so we can still focus especially in the last few hours, we also need the ability to capture only the important and the keywords from the overwhelmed information provided, and possess a broad and high level design experience in different type of network and industry to make us familiar with the challenges
We Need to Do "High Level" Troubleshooting Too
- It seems like the exam maker thought it was not enough with only the number of design decisions we must do, we also need to do some "high level" troubleshooting
- We may be asked to figure out what's wrong with the network or design flaw causing network issues, and instead of doing debug we must analyze it from series of information provided (sometime we need to choose which questions and further information to ask to the customer)
- Again, I believe for this part we have to rely on the experience with high level design, the logic and ability to capture only the necessary information, and possess the knowledge of technology overview instead of in depth/bit level details since we can't do any debug
And In the End, When We Fail
- Unfortunately even if we fail we may not able to be more prepared in the next attempt
- At least in CCIE lab if we can't ping definitely there is something wrong with our setup, and after we fail in CCIE we are presented with the break-down score for each technology section so we know which part is our weakness
- The CCDE exam contains multiple scenarios and bunch of questions for each scenario. From one scenario the questions may cover the routing, security, tunneling, management and Quality of Services technology areas and personally I'm not sure how I can figure out on which part is my weakness if I really fail (unless the score report can break it down per technology area for each scenario)
In summary, I fully support the statement of CCDE practical exam is as difficult as CCIE lab, even their coverage is not in the same context. And it may be more difficult if we consider the fact that we won't know for sure if we make mistakes. Even I feel like the design knowledge required to pass is more on the high level, but the most important things to have are the designer logic, broad knowledge of technology areas and the ability to capture only the necessary information before making any design decision.
So I think we need the above points I mentioned to pass this exam. But I can be sure only after I got my CCDE number, either in this attempt or the next.
Here is a link to CCDE practical tips from another test taker.