Friday, May 4, 2012

Why Should a CCIE Read Standards?


The stud/maintenance process for the CCIE exams is a long and difficult process. It takes an incredible amount of determination and self discipline to successfully understand everything that needs to be understood by a CCIE to effectively manage, evolve, and troubleshoot a complex Enterprise network. Cisco develops exam objectives loosely using Bloom's taxonomy. In the case of the CCIE Routing and Switching exam, all of the topics start with the word "Implement," "Evaluate," "Determine," and "Suggest."

There is probably a large potential debate about what the word "Implement" actually means, but I'll give my definition of what I think it means:

In the CCIE exam objectives, the combination of terms above around a given technology likely result int he following skills:
- Understand all of the concepts with a given technology and be able to unambiguously explain key terms and recall key facts
- Explain differences between the standard and the vendor-specific implementation
- Determine where a technology fits in a given network architecture
- Successfully design and optimize using the given feature/technology
- Evaluate a proposed design and develop positive and negative aspects and counter the proposal with design improvements
- Understand and code all of the related technology parameters and configuration options
- Explain how a technology works with technologies in higher, equal, and lower layers of the OSI model
- Evaluate the steps from start to finish to implement a change
- Explain the business impacts of making a specific change

Basically, in a one sentence summary: Effective operation at the CCIE level requires critical thinking, evaluation, and implementation using any feature/technology that exists in the networking industry regardless of whether Cisco implements it in a specific product or line of products.

This provides an insight into the title for this post. The level of knowledge required for the CCIE cannot be attained through memorization alone (in fact, memorization without context will likely hurt the CCIE candidate's chances for passing the exams on the first or second try). Simply, too much needs to be understood to be memorized. So why read standards?

Standards offer the CCIE candidate a complete, unabridged coverage of a technology or topic. Whether it is a set of RFCs released by the Internet Engineering Task Force or the authoritative electrical and mechanical specifications published by the IEEE, a topic can be comprehensively understood and applied by understanding the standards. Starting fromt he beginning, a CCIE can understand how a technology evolved and predict the future direction of a feature/technology.

Reading anything besides an authoritative standard is a paraphrase/summary of the standard. Depending on the source, a summary might be incorrect or provide an incomplete/misleading picture of what a technology/feature achieves. If a candidate uses the Cisco Press books to achieve the CCNA/CCNP, then they have gained a simplified understanding of the main technologies used in enterprise networks and may know the main features of technologies like Ethernet, Frame Relay, IP, TCP/UDP, but their level is likely at the "memorizing" level of understanding. This is not to say that the CCNA and CCNP aren't important, rather they help build some of the summary understanding required to successfully read/interpret a difficult IEEE standard or RFC.

Reading standards takes a candidate beyond memorization to a comprehensive end-to-end understanding of a protocol or technology. To achieve "Expert" status, this is really what is required. It's not easy, takes a lot of time and patience, but ultimately ends up in a level of knowledge where memorization is neither helpful nor required. Instead of memorizing the fields of an Ethernet frame, a candidate can break down why each field is present, where it originated, and can build an Ethernet frame without actually memorizing any fields. I structure my post on Ethernet basics in this way, by taking a bottom up approach from the 802.3 CSMA/CD fields to 802.2 LLC fields to RFC 1042 SNAP fields. By having read the majority of each of the standards, I know everything that needs to be known to create a layer 2 frame using Ethernet.

Would-be CCIEs who don't want to read standards and build a complete understanding are probably better off pursuing a different certification or staying at the CCNA/CCNP level. It simply takes too much time and too much effort for most people to gain the required level of understanding. Those who manage to magically pass the CCIE based on memorization alone give every other CCIE a bad reputation because they lack the knowledge that is required to be effective in an advanced network engineering role. This is why Cisco has made every effort to make the CCIE differentiate the top 1% of the networking world.

For those studying for the CCIE, understand that it is a long and difficult process. Most people can't complete the required study in 6 months and many can't complete the required study within a year. For many, it takes years to develop the required mastery of networking. If you measure the CCIE in pages of reading, you are easily into the tens of thousands...

Best of luck to those of you who are working towards this certification.

Below is a list of standards that I've found helpful in understanding the topics required for the CCIE (though, not a complete reading list and also not complete at this point):

Institute for Electrical and Electronics Engineers:
IEEE 802-2001: IEEE Standard for Local and Metropolitan Area Networks: Overview and Architecture
IEEE 802.1d-2004: Media Access Control (MAC) Bridges
IEEE 802.1q-2011:  Media Access Control (MAC) Bridges and Virtual Bridged Local Area Networks
IEEE 802.3-2008: Carrier sense multiple access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications
IEEE 802.2-1985: Logical Link Control

Internet Engineering Task Force (IETF):
RFC 1042: A Standard for the Transmission of IP Datagrams over IEEE 802 Networks

The Broadband Forum (formerly the Frame Relay Forum)

See Also,
The Road to the CCIE

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