Thursday, July 1, 2010

CCIE R&S Preparation has Begun!

Well, I've finally finished reading the glorious 1000-page CCIE Routing and Switching Certification Guide v4 by Wendell Odom, Rus Healy, and Denise Donohue, and I've passed the Written Exam; so, it's time to begin lab prep! That Odom book was really great, and I really enjoyed the IPv6 and MPLS chapters.  Most of the errors I found were corrected in released Errata; however, one still has not. Don't let this trip you up: regarding 3560 Switch QoS on page 558 it states the following in regards to Egress Queues:

"Both shared and shaped mode schedulers prevent the PQ from exceeding its configured bandwidth when all the other queues have frames waiting to be sent. The shaped scheduler never allows any queue, PQ or non-PQ, to exceed its configured percentage of link bandwidth, even if that means that link sits idle."

"The expedite queue is a priority queue, and it is serviced until empty before the other queues are serviced."

I ran this by a few other engineers, and they also agree with this assessment, that it will indeed starve the other queues unless you explicitly configure policing.  I'm also surprised that the book never mentions that Spanning-Tree BPDUs are sent to the MCAST address 01:80:C2:00:00:00.  There's also not much detail on QinQ tunneling, and I had to access other resources to get the config portion.

When I was preparing for the the Voice lab, I spent about 18 months! That included about 8 months to complete the CCVP, 3 months to prepare for the Written, and about 5 months of prep for the Lab. And now another journey is under way. I tentatively have a lab scheduled for Oct 2010, and I plan on going through all four INE books before then. I was shocked however to recently open up the first workbook and find 2600 pages waiting to be covered! It's gonna be a busy 6 months ahead!

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