Interview – Interview with Renowned Trainer Jeremy Filliben

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Hi Jeremy Filliben,

Welcome to Networkcareer!

JF: Thank you for the opportunity to participate in the site!

Where do you work and what’s your role?

This is a surprisingly difficult question to answer! I work for a number of organizations, but the best way to answer this question is to say that I work for myself. While it may seem strange, I feel that everyone in our industry should look at their career in this way. I have spent the majority of the last 15 years working directly for a larger insurance company, but I also spend some of my time consulting for service providers, small businesses and other corporations. I am probably best known for providing training for the Cisco Certified Design Expert program.

What kind of roles and work did have you been through before?

I started out in networking at a plastics company. While there I earned my CCIE certification. Once I outgrew that role I moved into consulting for various companies (Chesapeake Computer Consultants, RPM Consulting and Netigy Corporation). Getting into consulting, especially at such an early part of my career, allowed me to gain a lot of experience in a short time period. When the consulting industry shrunk in the early 2000s, I moved on to a direct contracting role with General Electric.

What have you learned in your career so far that you would like to tell the younger you?

If you speak with any experience CCIE, he or she will tell you that the day they passed the CCIE lab was the day they were most confident in their technical skillset. For me, June 16th, 1998 was the day I was certain I knew everything there was to know about networking. It did not take long for me to realize that this was just the start of my learning. I wouldn’t say I was every cocky, but I had an unearned confidence that may have come across in a negative way. My advice would be to be more humble. I eventually figured this out, but I could have learned the lesson earlier.

What are the most important skills you have picked up in your career so far?

Technical skills are critical to this industry, but they are also quite transient. I used to be a wizard with PIX firewalls (or at least I recall it that way). But I haven’t configured a fixup port in a decade. The most important “skill” I’ve developed is a good reputation. The best way to do this is by completing the work that you have been assigned, and always having a positive attitude. You’re your colleagues and managers informed of your work, even when (especially when!) things aren’t going well. Good, frequent communication is immensely valuable.

What’s your opinion on degrees? Are they useful for someone in the networking industry?

I believe my Computer Science degree helps me quite a bit in my career. There are key concepts that I learned in college that make my job considerably easier. It’s difficult for me to pinpoint them exactly. An example might be learning binary math, and applying it to subnetting. My error rate in translating random ‘slash notation’ to dotted-decimal (/29 to for example) is significantly lower than it would be if I didn’t have the basics of binary math. And it pains me somewhat to say this, but all of those term papers about world history and philosophy certainly helped my writing.

What about certifications? Are they losing their value?

In general, I don’t think so. Legitimately obtained certifications are the easiest way for entry-level engineers to prove their knowledge. There comes a time in some engineers’ careers where his/her certifications don’t really matter anymore. This may be because they no longer work on that specific equipment type (3Com Wizard, anyone?) or their reputation is bigger than the certification. I think many engineers think they are in these categories, when in fact, they are not. I personally do not plan to abandon my CCIE or CCDE designations by going into the Emeritus program. At the risk of being controversial, I see the Emeritus program as form of ‘giving up.’ I don’t begrudge anyone their choice to enroll in the Emeritus program; it just isn’t for me (at this time). My training business makes this an easier decision for me than for most.

Is the skillset of network engineers changing? What skills are important to have in the coming years?

A good network engineer’s skillset is always changing. If someone wanted to do the same job repetitively, year after year, they got into the wrong business. From 2001 – 2004 I worked in the global NOC for General Electric. For most of that time I was assigned the same general tasks (trouble tickets and minor network design projects). Fortunately, my management team allowed me the flexibility to request more challenging work. Even though the pay was good, I would have left if not given these additional opportunities. As I stated before, you work for yourself; it just happens that others pay you for the effort.

What skills are important for Network Architects?

Besides the obvious technical skills, it is important for Network Architects to understand the business side of, well, business. Two companies may appear to have similar network needs, but by properly understanding their business plans I may develop very different network designs. As an example, two companies may each have two data centers and thirty branches, but if Company A is a high-growth retailer, while Company B is a no-growth manufacturer, their requirements are actually quite different. Or perhaps one of the two is a stock trading institution, while the other is a chain of coffee shops. Security requirements may be quite different. A good architect can recognize these differences and build an appropriate list of questions for the business to determine their specific requirements.

Will the need for networking experts go away? Is it better to be a generalist than an expert?

My superficial answer is that a generalist will have more opportunities, but a specialist will have more success. Over my career I have seen that experts do considerably better than generalists. Most companies hire to fill a specific need. Meeting that specific need is usually the key to getting hired. I will say that I rarely meet the die-hard specialist in real life. Almost all specialists are generalists, who happen to know one thing extremely well. As an example, I have met true experts in IP Multicast; the type of engineers who almost always know the root cause of an issue based on a quick description of the symptoms. These engineers are clearly IP Multicast specialists, but to get there they needed to understand unicast routing, switchport buffering schemes, Linux/Windows OS details and more. It was only after developing those skills that they were able layer on knowledge of IGMP, PIM, RPF checking, mroutes, etc.

What do you think of soft skills? Do we need them in the networking industry? If so, which ones are the most important?

While I sort of hate to say this, good engineers can get by with so-so soft skills. While it will hold them back from future opportunities (they probably shouldn’t get into consulting or management), they can earn good salaries based on their ability to solve technical problems. The stereotype of the lone, difficult hacker (original meaning of the term) exists for a reason. That said, excellent written and verbal communication are somewhat rare in our field, so an engineer who possess these can easily stand out from the crowd. Oh, and Visio or an equivalent. Even great engineers can be bad at diagrams.

With SDN, orchestration etc. can we throw the “traditional” networking knowledge out the window? Why or why not?

Of course not, you must understand something before you can automate it. Otherwise you are simply going to break more things in a shorter amount of time!

Should someone in the networking industry learn to code? Why or why not? What is your language of choice?

I have a CS degree, and I have a love/hate relationship with programming. I create the occasional tool that helps me automate my work, but I have never sat down and created a full-fledged application. I would call my work more scripting than coding, and certainly not legitimate programming. I know a bunch of dead/dying languages from my university days, and I taught myself enough Python and Apple Swift to be useful. I prefer Swift, but the networking industry in particular seems to have standardized on Python.

What’s your best advice for staying updated in the networking industry? How do you stop the sipping from the firehose?

I use Feedly to follow my chosen news sources; mostly networking blogs. I regularly attend Cisco Live. If you can’t attend in person, the free resources on provide nearly all the networking knowledge anyone can use. I also enjoy the Network Break podcast from Packet Pushers. It does a nice job of filling in the gaps that I miss by not reading industry publications. I am also fortunate to teach network design for Cisco CCDE candidates. This provides me regular opportunities to test and expand my knowledge. Students ask the best questions!

Before we close out. What would you want to give as a final piece of advice to the NC readers?

If you intend to stick with networking, know that you have chosen a profession that demands life-long learning. If that scares you, move on to something else. You won’t keep up with your peers and our industry, and in a decade or less you will be practically unemployable. I have seen many engineers burn out during my twenty-year career. It profoundly saddens me to see parents in their 30s and 40s who cannot find suitable employment that meets their family’s requirements. There is never a time in this field where you’ve “made it” and can now relax. The hot technology that earned you the big bucks this year could easily be unwanted next year. If you read this far, good for you! You must be excited by the idea of constantly learning. It can get frustrating at times, and occasionally you will feel burnt out. This seems to happen during the pursuit of a difficult certification, and strangely, a few months after achieving such a certification. Give yourself some time, it will probably pass.


  1. As a network engineer, I agree with the author on many points. The last part/paragraph is the most important one: “There is never a time in this field” – networking – “where you’ve “made it” and can now relax. The hot technology that earned you the big bucks this year could easily be unwanted next year. […] You must be excited by the idea of constantly learning. It can get frustrating at times, and occasionally you will feel burnt out. ” In my experience this is true.
    For example, knowing Python (scripting, not coding) is almost a must.
    I do not agree on the value of certifications: I’ve met people who have become exceptionally skilled and competent as network engineers without any certification, and they should be proud of it. They prove that it’s not necessary to spend money on certifications, especially if they are demanded by the same industry that profits from them.
    My two cents 🙂

    1. Hi Sophia,

      Thanks for commenting. I don’t think anyone here says that certifications are a must to be knowledgable or to become successful. If you use them as a learning path they are very useful to gain a lot of knowledge in a shorter amount of time than you normally would when not going after a certification. Certifications, degrees etc. are just tools you can use to further your career. Having more tools are good but you need to use them correctly and at the right time to maximize the effect of it. Degrees and certifications hold the most weight earlier in your career than when you are already a well established engineer with 10 years of experience.

      That’s my view anyway 🙂


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