One of my goals for 2019 is the brush back up on networking theory/operation after the last couple of years focused on network automation. This is a bit of a brain dump about my adventure in pursuit of the JNCIA-Junos certification and the study materials I used.


I have worked as a network engineer for 10+ years and spent most of my time working with Cisco products on the network side of the house. Over the last couple of years I have worked at a mostly Cisco allergic shop with Juniper being the preferred network vendor.

Although I am not in operations I work with Juniper routers/switches/firewalls a fair bit in order to apply automation magic to them. I am certainly no Junos wizard and I took about 6 months from thinking about getting certified to feeling like I had prepared enough to confidently take the exam.


I feel like I had a good enough handle on the fundamentals to skip over the parts around the OSI model, subnetting, what is a router, switch etc... I read the three day one books cover to cover and the parts of the cert guide and study guide that made sense based on the blueprint.

Title Author(s)
Day one exploring the Junos CLI Walter Goralski, Sean Clarke, and Ian Jarrett
Day one routing the internet protocol Martin Brown and Nick Ryce
Day one Junos monitoring and troubleshooting Jamie Panagos and Albert Statti
JNCIA: Juniper Networks Certified Internet Associate Study Guide Joseph M. Soricelli with John L. Hammond, Galina Diker Pildush, Thomas E. Van Meter, and Todd M. Warble
JNCIA-Junos Study Guide-Part 1/2 Unknown Author(s)


The Pluralsite course from Rich Bibby was a pretty good introduction. It was high level but enough to give me a good idea of what I needed to study deeper.

Title Author(s)
Juniper Networks JNCIA-Junos (JN0-102) Rich Bibby

Other Tools

Juniper Genius

The Juniper genius app has two JNCIA practice exams. I completed them both getting 80 and 85% respectively. Any question I had to guess, got wrong or was unsure about I wrote down and went back and researched the topic more. This was a big help, although none of the questions were in the actual exam, the subject matter was similar and it helped me identify the areas where I needed to spend more time studying.

Juniper Docs

The Juniper docs are a good resource and where I went searching when I needed to clarify something that I wasn't sure about from one of the books/videos. They also have a lot of configuration examples which helped me understand the Juniper way of doing things via the CLI.


I built a vendor agnostic lab topology which I used for most of my labbing. Having the base configs already applied and being able to rollback to a baseline state quickly really helped pump in as much quality lab time as possible. I did not actually spend a large percentage of time labbing, but what I did do was very productive.

Liquid Text App

Liquid Text is an IOS app that allows you to take notes on a PDF and the notes are linked in context to the document. You can write directly on the document or there is a side panel for copying text or writing your own notes / diagrams. I felt like this was a great time saver when going back for revision of something I had noted but didnt quite understand or had forgotten.

Time Budget

I dont have a concrete answer as I really didnt start accurately tracking my time until the middle of January when I thought It might be good (or sad) to see how much time I was actually committing to this goal. My recorded time was 50.5 hours but I would estimate it was closer to 100 based on what I had done in the months prior to Christmas 2018.

Study Notes

Below are the links to my study notes. They may not make sense to you if you are not me, but they may be helpful to give others and idea of what to look for.

I also documented some quick reference configs here

Calculated Omissions

I took a bit of a gamble and skimmed over QoS without spending too much time on it. QoS I am familiar with (not Juniper specific) but I guessed/hoped there would not be a ton of questions and I can focus on it properly and give it the attention it deserves if/when I do higher level Juniper certs. I took the same tactic with uRPF although I am familiar with it, I will look at it more deeply in the future.

The Verdict

I am pretty happy that I went for this cert. It helped me get a good handle on the operation of Junos and how things are done in Juniper land. I completed my CCNA over 10 years ago now and from what I recall that was a harder exam with more generic network theory questions (I also had zero real world experience at that time). I recall studying very hard for that exam and the fundamentals I learned still help me and are relevant to this day.

I thought the exam was pretty fair and a good level of knowledge for a junior network professional. Not many useless trivia questions and if you have been operating Junos devices, a lot of the answers made sense, where obvious or easily inferred.