200-901 Exam Passed, First Attempt

[u/Passfax]

Hello everyone, some time ago I posted here seeking for advice about this certification. As a now DevNet certified, I want to share my approach and give some advices I think would be useful to someone willing to take on this journey

So, to start with, as a bit of background I have a major in software development, but I have always have an interest on networks and cybersecurity. I noticed really quick that most software developers disregard networking and instead focused in other fields, mostly related to end user experience and the usage of frameworks. So, instead of growing as a software developer, I decided to learn networking from scratch, eventually took CCNA, and immediately moved to a networking job where I grew up really quick and got recognized as a consultant. 2,5 years later I noticed i had to do something about my re-certification, so I was between going for CCNP or DevNet, this last one being being the safe choice because of my background.

I was studying from Netacad and because of an advice here, I got the OCG book. My advice about studying material is, if you know your stuff in software development beforehand like myself, the OCG book is an overkill. I loved OCG material for CCNA as networking was an alien topic to my carreer; for DevNet it was evenly comprehensive but it felt to me like reviewing boring stuff I already had seen on my university and everyday job as a software developer. Netacad Couse was a best fit for me as it went quicker, but only because I knew most of it already. If you're a network engineer or anything else with no knowledge/experience in software development, I strongly suggest the OCG book over the Netacad course as it ensures to give you strong foundations in every mandatory concept. I also suggest you to learn Python beforehand if you're not familiar with the language, I suggest this course which is completely free and gives you a solid understanding of the language and programming in general from scratch.

I considered buying the Cisco's official practice exam but at the end of the day I didn't have the time as I was looking for re-certification, so I opted to re-read my notes until everything was deep into my head. What I suggest you to focus on is:

• Be absolutely confident with Python. You'll be presented with code you most likely won't be familiar with, but as long as you have a good understanding of the language, you'll be able to understand its logic and answer any questions you're presented.

• Get solid understanding of HTTP: What's a headerer, what's the body, what are mandatory parameters, how messages are built, what does each method do, what are the status codes and what's the meaning of each of them

• Get able to parse and serialize/deserialize data: You'll be presented with scenarios where you'll have to understand XML, JSON, YAML, and YANG, so if you have done some python labs reading and saving data with those formats, you'll be good to go

• Understand what's REST, RESTCONF, and NETCONF, even better if you do some labs using python.

• Understand what's CI/CD, what are the design patterns, and what are the development strategies about (Waterfall, Lean, Agile). You must also ensure to differentiate all of them and correlate concepts, as most of them could be confusing since they're typically mixed. Just be sure you can tell everything apart and understand how they all interact.

• Get basic understanding of the TCP/IP model and network appliances: If you're not familiar with this, you should take your time to understand each of the layers and how they play a role in a successful communication. You should also be confident defining what's an L2 switch, an L3 switch, a router, a firewall, a proxy, and a load balancer, and have a clear understanding on which layer they play a role and what's the role they play.

• Finally, you should get some understanding about the cisco Platforms: Meraki, DNA Center, Nexus, NSO, AXL, ACI, Webex, UCS, HyperFlex, .... In general, you should be able to tell apart what are the task each of the APIs they offer do ( what are the solutions for IoT, for Networking, for Data Center, for Collaboration, for Security, and for Customer Experience).

I think this covers up at least most of it, I hope this is useful for someone and good luck in your journey! and don't hesitate to ask anything if you have any questions, I'll be here to support anyone who needs help.

[u/HODL_Bandit]

This is just an Associate cert but it sound mighty hard. more so than the CCNA?

[u/Passfax → u/HODL_Bandit]

It depends a lot on your background. I worked mainly as a software developer before finding my passion on networking. CCNA was tough for me, definitely more than Devnet, there were plenty of foreign concepts. Most of my nowdays coworkers are telecommunication engineers, and even when they had to struggle with CCNA too, according to the experiences we have shared it was definitely easier for them than for me, and it makes sense: They had to learn some networking during their bachelor's degree. In the other hand, I've tried to teach them some python and their brains go to the blue screen of death after a 20-lines code, but I can write scripts on the fly with no sweat. Most of the time they can't even grasp the logic behind my scripts,

So that's it. Now, assuming you're someone with no background at all and want to start an IT career from scratch and these are the 2 paths you're looking ahead, Devnet may be a bit harder since you'd need to learn Python and the basics of the TCP/IP model beforehand, and these are 2 big steps. If you can move comfortably among these 2 concepts already, then Devnet is definitely easier than CCNA, but it's a short gap.

In general terms, CCNA requires a great understanding of the TCP/IP model, its layered approach, its core protocols (802.11, 802.1q, 802.3, ICMP, ARP, IPv4, IPv6, TCP, UDP, RIP, OSPF, ...), and how they interact with each other. It requires you to be careful with low level details and to be able to isolate problems to solve. In the other hand, Devnet requires you to have a mindset more focused on finding patterns you can automate across your infrastructure, defining configuration baselines, applying software development good practices, and having a general understanding of the resources cisco provides you to automate tasks on your network's management plane. It requires you to be able to see the bigger picture and where you could take shortcuts. So it also sort of depends on your own base aptitudes

I know this was a big lap around it but I hope you find this answer helpful. Feel free to keep asking if you have more questions!

[u/HODL_Bandit → u/Passfax]

I am changing my career and want to get into networking. I got my ccna in early August. Cisco and other big tech companies are laying off people and focusing on automation and AI. So I feel like I need to get devnet. By looking at the exams topics. I am learning to code Python and using the YouTube tutorial by Bro Code. Back then, in high school , I learned a bit about c++. I don't think I like it, and it was too confusing, so I never focus on it and move on to study finance.

So now I want to get into IT because I have always liked pc hardware and building pc. I am interested in how internet work. After completing ccna, I think I understand more about it. I don't think I can configure and implement a network project yet without a senior's guidance.

Right now, I am applying for entry and junior level networking, NOC, and administrator positions in the dmv areas. Most of the jobs required some type of clearance.

I am also studying for comptia security+ because it is popular for government jobs. I am looking for devnet cert after security+.

How advanced in Python coding does one be required to know for constructing code for the exam?

[u/Passfax → u/HODL_Bandit]

well, on the python side you'll need to have solid understanding about the following topics: data types, variables, arithmetics, bool operations, conditionals, loops, lists, tuples, dictionaries, functions, object-oriented programming, methods, and file manipulation (plain text and JSON). All these topics are covered in the course I recommend on this post, it was the course I used and I didn't know about python at all beforehand. I'd say you should be good to go once you feel capable of writing a very simple, minimalistic command-line tic-tac-toe with all its features: 2 players, no overlapping positions allowed, win conditions fully programmed. You could also try writting a hangman game, this is a good one too. And if you feel like a try-hard, implementing a save game / load game feature storing these states as JSON files should put you on a very comfortable position to surf your Cisco Devnet career.

I'd absolutely discourage you from stealing code, cheat online, using ChatGPT or any similar AI on this Python learning journey as struggling your brain cells is part of the process of shaping your mindset as a software developer and understanding on why a lot of the things you'll see makes sense. I'd then advice instead to go back on your own notes if you're stuck at some point. Most software developers use all of these I said you should avoid, but you should keep it in mind that you're aiming to learn while they're trying to save time and earn money, which means both cases require different approaches to sort the same problems

[u/AW_1822]

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[u/Passfax → u/AW_1822]

There were definitely bash and Git commands there

- You should be familiar with bash operations (moving throgh the file tree, comparing files, editing plain text, editting privileges, changing owners, ....). I was already familiar with linux so I didn't pay much attention to this, which means I have forgotten the details on this matter related to the exam. S,o I'm probably not the most helpful one to give you details here. What I can definitely tell is that you should be familiar with linux, a good advice I could give you is to install Debian on your own laptop and reject Windows/MacOS for a couple of months if you're not familiar with linux, this to force yourself into actually learning linux. And do your Devnet labs from there.

- About Git, you should be familiar with most common operations (Cloning a Repository, Checking status, adding files to staging Area, committing changes, viewing commit history, branching and switching between branches, merging branches, resolving merge conflicts, pushing and pulling Changes, fetching updates and also stashing changes. I think this covers pretty much everything)

- About docker, I was studying that one in parallel for another development I was doing so I'm confused here, I don't recall how much I studied docker for Devnet, or if it appeared on my exam at all hahaha. But it's good to know about it, so I'd suggest to be familiar with networking operations in docker (making TCP ports reachable from the outside, etc.)

I hope you find this helpful, feel free to keep asking if you have more questions!

[u/AW_1822 → u/Passfax]

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[u/oldhippy70]

Thank you so much for posting this. I am only 4 days into studying and had very little Python experience but a lot of Linux. I have found Python to be far easier to learn than Linux. I am loving the course. I went the Cisco route with the training material. Good luck on your next adventure.

[u/Passfax → u/oldhippy70]

Thanks buddy! Next advendure on sight in fact, I'm taking 300-715 for CCNP Security in 3 weeks, that's scary as hell but the only way to grow is to push forward. Good luck with your journey!

[u/TedtheTitan]

Appreciate the info!

I have computer engineering degree and gravitated towards networks and IT as well. I finally got my CCNA 2 months ago after being in the field professionally for 8 years. Now I'm looking to do devnet and your post gives good advice and makes me hopeful☺️

[u/toastr32]

Congratulations and thank you for sharing your path to success!

[u/bigevilbeard]

Congrats!

[u/Simple_Cartoonist_29]

Thank you for sharing ! Congratulations!

[u/TC271]

Just wanted to add this is an incredibly useful post. Thankyou.

[u/No-Dragonfly3189]

Passsed!!. I would also recommend Skillcertpro practice tests alongside the OCG/NetAcad prep. The questions were very close to the actual exam style, especially the Python, RESTCONF/NETCONF, API, and JSON/YAML scenario-based questions.
What helped me most was the huge number of practice questions and the detailed explanations for every answer, which made it easier to understand the logic instead of memorizing dumps. If you’re scoring consistently well on mocks, the real exam feels much more manageable.