Interview with Jeff Doyle

Clique aqui para a versão em Português

Hello everyone! Again, I was delighted (and honored) to be able to interview one of the great minds of the networking industry. For those who are not familiar with Mr. Doyle (I believe not many will fall into this category), is the author of several best-seller networking books, two of which – TCP/IP vols 1 & 2 – being considered the “bible” for those preparing for the CCIE, not to mention he is one of the top ranked IPv6 and routing protocols specialists nowadays.

I will be publishing this interview in English only, this time. This is to force you guys to READ in English, or at least to make an effort 🙂 (worse case scenario, you can always use an automated translation tool, such as Google Translate).

Hope you all enjoy reading it as much as I have enjoyed doing it 😉

<—— Interview begin ——–>

Hello Mr. Doyle, first of all, I would like to thank you, on behalf of all blog readers, to share a little amount of your valuable time with us. We all hope you enjoy very much your staying in Brazil, and also that you succeed on the job you have been hired to perform – but that goes without saying 🙂

I have put together a few questions, some of which being suggested by the blog readers. Please, feel free to respond them as you wish.

Again, many thanks for your time.

<—— Interview questions begin ——–>

As with what happens around the world, your books are highly recommended here, in Brazil, to those pursuing the CCIE certification. Having said that, your readers would like to know: Do you (and CiscoPress) plan to release an updated version of your TCP/IP books? If so, can you talk about what will be the major changes? 

I am currently working on a second edition of the second volume of Routing TCP/IP. We don’t have a release date yet, but it will be significantly changed from the first edition. The BGP chapters are widely expanded and completely rewritten, spanning 6 chapters (the first edition had just 2 chapters on BGP). These new chapters not only provide coverage of the many new BGP features in IOS since the first edition, they also incorporate the many BGP best practices that have evolved since the first edition was written.

The Multicast chapters are also changing, eliminating much material from the first edition that covered protocols no longer used or never put into general usage.

The third significant change is the incorporation of IPv6 throughout the book: Coverage in the new Multiprotocol BGP section will include different IPv6 peering practices; IPv6 multicast is covered; the NAT chapter is expanded to cover NAT64/DNS64 and Large-Scale NAT architectures; and a chapter on IPv6 tunneling will be added.

You have established a firm known as “Jeff Doyle and Associates, Inc.”. The fact that you are consulting in Brazil only proves how successful this firm is. Can you talk a little about what your company does?

Although we are happy to work with any network of any size, Jeff Doyle and Associates specializes in large service provider networks and the complex design challenges around those networks: MPLS, traffic engineering, complex BGP policies, QoS/CoS, and of course IPv6 deign and deployment. Most of my work lately has centered on IPv6, simply because that is what most service providers (particularly broadband service providers) are heavily focused on now.

The “Associates” part of my practice is built around an association of other highly experienced independent network architects. The advantage to my customers of this model is that “on the bench” employees are not a factor in my recommendations to my customers. I find the best fit for the customer’s needs, and always use consultants whom I know and trust.

Readers are eager to know what would you classify as the greatest professional challenge you have ever faced. Can you briefly share it with us?

Just keeping up with the evolution of network technologies and best practices, I think. I have always been a consultant of one type or another, and that helps tremendously in getting constant exposure to different networks, different network operators, and different design challenges. I’m frequently tempted to “settle down” and work for a single network operator; getting to intimately know one large network has it’s appeal. But knowing that my knowledge of any technology or practice not used by that operator would quickly stagnate keeps me from making that change.

I think it is safe to say you might be one of the most knowledgeable IPv6 professional today. With that in mind, what can you recommend to those who are starting their studies on this protocol? 

Understanding the basics is essential of course, and this is easy to learn; there is a wealth of material available. Beyond that:

– Keep track of what is happening in the industry. Although the protocol suite has been around for a long time, practical experience is still developing, and hence best practices are constantly changing.

– Learn how to make a business case for IPv6. One of the reasons it has not been deployed earlier, in my opinion, is that engineers have seldom been able to make a convincing case to executives of why they should spend money deploying something that has no apparent business advantages. (Hint: IPv6 is an infrastructure issue, not a services issue. IPv6 is being deployed not to create new revenue streams, but to allow the business to keep growing.)

– Learn the principles of IPv6 address design. The biggest challenge here is abandoning the IPv4 address design principles we have all used for decades, and which are primarily centered on address conservation. IPv6 allows us to be wasteful with addresses in exchange for address designs that are simpler, more scalable, and more flexible.

– Learn what transitional technologies are currently in use, and the challenges of each (they all have challenges of different forms). Learn IPv6 can impact applications, and how to plan for that.

– Learn how IPv6 impacts network security and what factors must be considered when securing IPv6.

– Learn the issues around DNS for IPv6. Some of the biggest challenges in an IPv6 deployment can be getting DNS right.

Regarding the IPv6 deployment, it is common knowledge that we had almost 15 years to prepare, and only a few years ago we actually start doing something about it. How do you see the IPv6 activation process, worldwide? Are we really that late? What would you say are the major challenges to be faced by the organizations through the implementation process?

From a purist viewpoint, yes, we are very late in deploying IPv6. Had we started a decade ago, before Iv4 address depletion became a serious problem, dual stacking (the simplest approach to IPv6 deployment) would have been much more feasible. Now, with IPv4 depletion a reality and public IPv4 addresses hard to come by, we are having to resort to much more complex and disruptive “transitional” technologies like Large Scale NAT (LSN) and NAT64/DNS64.

But from a practical viewpoint, where we are now fits with general network economics: Most network operators tend to put off the expense of any new technology deployment until the technology is unavoidable.

As far as the state of deployment, we are still very much in the early stages. Almost all service providers worldwide have active IPv6 deployment plans, but very few have completed them. The great majority of broadband customers still cannot get native IPv6 service in their home or small office (including me). And enterprises are much further behind. Most of them are only beginning to ask the kinds of questions service providers were asking 6 – 10 years ago.

The biggest challenge most operators are facing is not vendor support, as one might suppose – as long as you have a good long-term plan, your vendors can keep up – but negative impacts on applications. In my experience application testing and certification has been the most unexpected challenge in most deployment projects and the most complex.

What do you see as a major competitive advantage to a Networking Professional nowadays? Rephrasing that, how would you describe the perfect networking professional in terms of academics, certifications and skills combination?

Speaking as someone who has conducted hundreds of technical interviews over the years, certifications are a good way to get initial attention of a potential employer. But demonstrable experience and knowledge is far more important. When I am preparing to interview a job candidate, I look carefully at what his or her past job experience has been and what the implications of that experience is (that is, what level of ability has the candidate developed working at a specific network). In the interview itself I am looking only partly at how well the candidate can answer technical questions; I’m paying much more attention to how the candidate can analyze what I’m asking and develop an answer. In fact I generally like to ask a few questions that I know the candidate cannot answer, to see how well he can use what he does know to get close to an answer.

All of this is to say that your career plan should encompass several areas:

– Incrementally develop your practical experience. As you master the skills of your present job, begin looking for a job that offers new responsibilities. Plan on being in learning mode throughout your career.

– Develop your spoken communication skills. Learn how to clearly express yourself in meetings. Take some public speaking classes or join a speaking club like Toastmasters. Look for opportunities to speak in front of audiences.

– Develop your written skills. Every network professional has to write reports of some sort or another; a network architect spends most of his or her time writing. As you improve your skills, volunteer to write white papers or policy guides for your company. Try writing a blog. Propose some articles to industry publications.

– Develop customer relations skills. This is particularly important for consultants, but is also important for anyone that deals with customers either internal or external to your company.

Would you be so kind to recommend some IPv6 specific sites and literature to the rest of us?

There are so many sites it is hard to recommend any over others. I tend to just use Google if I need to research a specific IPv6 topic. But Gogo6 is a nice resource and a good site for general discussions. I do make specific recommendations for books, however:

– Silvia Hagen’s “IPv6 Essentials” is an excellent beginning book.

– Marc Blanchet’s “Migrating to IPv6” takes you from the beginning concepts into practical knowledge.

– Shannon McFarland’s “IPv6 for Enterprise Networks” goes even further into practical deployment.

– Scott Hogg and Eric Vyncke’s “IPv6 Security” is the authoritative book on that subject.

– Qing Li’s books on IPv6, beginning with “IPv6 Core Protocols Implementation”, provide a deep dive into all aspects of the protocol code. Essential reading for developers and anyone needing a serious “under the hood” look at IPv6.

All of these authors are people I know personally, and so my recommendations come from knowing their level of experience.

How do you see the Cisco CCA certification? Do you think the IT market is ready to absorb professionals that invest in and are able to achieve this major certification?

It probably depends on what your overall CV looks like – and this goes to my previous comments about interviews. All certifications are useful for getting the attention of a potential employer, and says much about your ability and willingness to devote time to your career path. But when you get to the level of the CCA, someone with that certification should also have a very impressive level of experience on the CV. If the certification is there but not the practical experience, the employer is going to notice. If the experience is there, it should speak for itself and the certification probably isn’t going to have much additional impact for the employer.

Some employers may eventually require a CCA certification as a job qualification, just as some employers currently require a CCNA, JNCIS, CCIE, or JNCIE as an entry qualification to certain jobs. And some employers may eventually need CCAs on their staff to maintain certain Cisco   partner levels, as they currently do with CCIEs.

Overall, it is too early to tell how valuable the CCA certification is to you, but an analysis of your present experience and your career plans should help you decide  if this is a good investment of your time and money.

Can you share with us how did you start into the networking career? Is there any advice you can give to the young people that are struggling their way out to enter this competitive market?

I sort of stumbled into networking. I was a working in telephony, maintaining business telephone systems and PBXs in the 1980s. More and more, maintaining data communications systems (mostly old IBM systems) became a part of the job. I became interested and studied the subject as much as I could, making sure my employer recognized my growing knowledge. Eventually I moved to a job that was exclusively data communications. From there I began writing educational materials and teaching classes internally, which helped me learn even more. I also became a Cisco Certified Instructor began teaching external Cisco classes. From there, I got my CCIE (this was in the days when the lab was still  days and the equipment was AGS+ and 4000s). I wrote a few articles for Cisco World magazine, which caught the attention of Cisco Press, who approached me about writing a book (which became the Routing TCP/IP books). At the same time, I left my employer to join a consultancy. My focus from then on was on building new experience and asking for new challenges.

Your career path might be significantly different; it’s a very different industry now than it was in the 1980s and early 1990s. But moving ahead is the same: Continually study, continually look for new ways to add to your experience, be sure your employer knows what you can do, and ask your employer for new challenges and new responsibilities. Look for ways to make yourself valuable to your employer, and don’t be afraid to look for a new employer if you have run out of opportunities where you are currently working.

<—— Interview questions end ——–>

Mr. Doyle, I would like to thank you once again to having accepted to take part on this brief interview. I am sure it will be very enlightening to our readers, and I am also sure they all will be very excited and grateful – as I am.

Best regards from Brazil,

Marco Filippetti (on behalf of CiscoCertified blog)

<—— Interview end ——–>

PS: Agradecimentos especiais ao Adilson Florentino e ao Adilson Bazan, por terem me ajudado com o contato do Sr. Doyle! Valeu pessoal! Vocês tornaram esta entrevista possível 🙂

18 comentários

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  1. O cara é simplesmente um monstro de redes!! Muito boa a entrevista Marco.

    É invejável o network que você possui, congrats!


  2. Awesome interview Marco. Congratulations.

  3. Show de bola.

  4. Muito bom!

  5. Muito boa entrevista, perguntas bem pertinentes.

  6. Muito legal essa entrevista !

  7. Parabéns e obrigado por nos dar a oportunidade de ouvir a opinião de uma pessoa com tão algo grau de conhecimento. Eu fiquei curioso em saber mais sobre a seguinte frase dita por ele: “The great majority of broadband customers still cannot get native IPv6 service in their home or small office (including me)”.
    Uma das perguntas que eu gostaria de ter feito a ele, era justamente essa. Não seria a hora das empresas (broadband customers) irem atrás da implantação do protocolo IPV6 e estar preparado para essa mudança inevitável?

    Parabéns mais uma vez.

  8. Muito boa a Entrevista….


  9. muito legal

  10. Muito interessante sua entrevista, Parabens ! Excelente Network.

  11. Wow Marco, it was an incredible interview!
    Thank you a lot.

    I’m so happy, I really liked the 6th question about career path, career development and job interview.
    And I liked your encouragement to us, I tought “Oh, I can’t read this in English, well, why not? Let’s try” And it was fun.


  12. Great interview Marco, well done!

  13. Great job!

  14. Ótima entrevista!!!

    Nada como ver a opinião de um “gigante” na área para nos ajudar a entender melhor. 🙂
    Gostei principalmente das recomendações para os que ainda estão estudando, dois quais, destaco dois pontos:
    1) Que devemos ficar atento às mudanças, pois, “although the protocol suite has been around for a long time, practical experience is still developing, and hence best practices are constantly changing”.
    2) Achei interessante também quanto ele ressalta que o IPv6 é uma solução para o problema de infra-estrutura e não um problema no serviço!!!Embora já sabendo disso, a maneira como ele coloca ajuda a entender melhor todo esse processo!

    Valeu Marco!!!

  15. òtima entrevista Marco.Obrigado por ter feito a pergunta que eu sugeri sobre a literatura IPV6!

  16. Gostei da entrevista, show de bola e o cara respondeu uma das minhas perguntas o que ele achava da nova certificação CCA. Congratulations Marco.

  17. Muito bom. Adorei as perguntas. Obrigado por ter incluido a pergunta sobre o volume 2 do livro dele 😉
    Achei interessante ele não ter nem mencionado a parte acadêmica, que eu pressumo se tratar sobre faculdade. Claro que a dica da oratória não podia faltar, ainda mais ele sendo um consultor!

  18. Muito Bom!!!!!!!

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