Carolyne Mwende
5 min readDec 31, 2020

We all have our paths in life we are supposed to follow to find who we are supposed to be, but it’s not always a straight path. There is something inside of us that guides us, and if you are quiet and listen to it, you’ll be all right.

Kyan Douglas

We all love to do that thing that makes us happy. That thing which you can do over and over again without getting tired or even for free and still feel satisfied. They say life is too short to do something that you hate for the rest of your life.

Choose happiness over anything else. I guess this is the reason why Jesus advised us to seek first the Kingdom of God, then these other things shall be added! Sorry my non-Christian readers…

After conducting a thorough personality test, I realized how wrong I was when I was forcing myself to master things that were not aligned to my personality. You can conduct yours today if you don’t know it yet using this link here. Yes, I love helping other people and leaving a positive impact on them, but how I achieve that matters as well, lest, I bring smile on others while I’m left wounded sort of.. on a light note though! 🙂

I have been in tech space for a while now, have tried programming in different languages; PHP, Java, Python just to mention a few, have also tried Data Science but I have never enjoyed any of them like I do enjoy Networking and cybersecurity.

Network and security

I will be sharing my little baby steps into networking and what I have learnt so far. Stay tuned!🙂

I’m not an expert yet, but i believe there’s power in sharing, unlearning and relearning. Otherwise how will I help someone out there with my little knowledge or unlearn/relearn if not by sharing?

So I will start with what I and my peers have been struggling to understand in Networking. Below are subsets of these challenging areas

  • Understanding OSI Model
  • What is subnetting and how to do it
  • What is VLAN and how to configure Intervlan Routing

Be my guests, let’s share and learn together. 🙂


I personally struggled to understand why I have to torture my mind with this OSI model thing! Urgh! I wasn’t getting it. I had to consult seasoned network engineers about this. If you want to be a professional network engineer, mastering an OSI model is a must. It becomes very beneficial when troubleshooting a network problems. You need to envision the model at the back of your mind, and start analyzing the problem at hand layer by layer until you successfully troubleshoot and solve the problem. Some of the questions you may ask yourself are: “is this a physical layer issue? if no.. is it Data Link problem? could it be Network issue? That way until you get a yes and solve the problem. It’s an efficient approach other than approaching the whole thing haphazardly.

OSI Model stands for Open Systems Interconnection Model. It consists of 7 ordered and numbered layers.

  1. Physical Layer
  2. Data Link Layer
  3. Network Layer
  4. Transport Layer
  5. Session Layer
  6. Presentation Layer
  7. Application Layer

The numbering and the order is very critical. In the real-world set up, you’ll hear someone say “aah, that’s Layer 3 issue?”, another one would say “It’s pretty clear that’s Layer 2 problem”. With this regard, you must know them by name and number. But don’t worry, someone came up with a Mnemonics to help us memorize the layers with a lot of ease. There are two mnemonics, Bottom up Please Do Not Throw Sausage Pizza Away and also up down approach All People Seem To Need Data Processing.

Ever heard of abstraction?

Do you know you use this OSI model almost everyday? When browsing… when sending a message to a friend.. when sending that job application to your potential employer..

You ask how?

Generally, all data transactions begin at the sending computer, travels down the 7 layers of the OSI model, starting with Application layer towards the physical layer. At the physical layer, the data is transmitted in form of bits(0s and 1s) through wired or wireless medium. On the receiving end, these bits starts travelling up the layers from physical layer towards the application layer. For instance if you want to connect to a particular website, you’ll type the name of the website on your browser. Once you hit enter, an HTTP protocol will take effect on the Application layer(if it’s an email, SMTP protocol). The packets are then compressed and encrypted(HTTPS by SSL) at the presentation layer. The web server will then acknowledge the client’s request at the session Layer. This information is then transmitted on the transport where the required ports are selected. (For web HTTPS request use port 443, SMTP for emails use port 25). At Network layer, the information is broken down into easy-to-send packets and IP addressing added on them. The packets are then send to the Data Link Layer where the Network adapter encapsulates them into frames of data. Then lastly at the physical layer, the network adapter breaks the frames into a serial stream of bits to be sent via cable or wireless media.

When these bits arrive at the recipient computer with a web browser, it’s reconfigured by network adapter as frames of information. The header information is checked for authentication and is tripped off, leaving the packets to be sent to the OS. Now the OS puts these packets together to form the web page which is displayed on the recipient’s screen. You wonder how long this process takes? It happens thousands times faster than explained here. Next article I will go deeper into explaining what each layer entails.

Thank you so much for reading this article. Looking forward to hearing from you.




Carolyne Mwende

She is passionate about life, breaking all barriers and leaving the world around me a better place to live in by putting God First.