A computer network is designed to connect multiple computers to send and receive data. Without this system, the ability to read this blog would be impossible. This is the foundation that everything in cybersecurity is built on. There would be no need to have a career in cyber if there were no network. The ability to understand the basics of a network is insurmountable in a cyber career.

How can you protect something that you don’t understand the basics of? Sure, I have seen people who couldn’t tell me what a switch is make it as a cyber professional. Buttttt, I wouldn’t call them great at it. So do you want to be sucky at your job? I’ll let you decide that. I think there are key ideas for having the basic understanding of a Network to be successful. You should understand some of the network types, topologies, devices, and protocols so you can better troubleshoot any network.

Network Types

When thinking of the types of networks you could run into as a cyber professional, there are a few that you should know and understand. One thing we MUST differentiate is that the INTERNET isn’t really a TYPE of network, right? It is how all networks communicate throughout the world. When thinking of these types of networks, we need to think of “Private”. These are all private networks that help connect people and devices from the same organization, or home… Your home is a private organization in a sense. Let’s start smallest to largest. You can find out in more detail from my discussion What are the differences between Network Types.

The first network type is the PAN – Personal Area Network. It is what it sounds like your person. Think Bluetooth—connecting all devices for your small radius of devices, phones, and headphones.

LAN – Local Area Network Think of your house or office as the local area, connecting all devices in your home.

CAN – Campus Area Network One that is often forgotten about or not talked about a lot. For this think college campus’. If your headquarters has multiple buildings on the same plot of land, this is more of a CAN than a LAN. However, I would argue that most professionals just call it the LAN.

MAN – Metropolitan Area Network Where you have multiple office sites in a big city, such as government buildings would be a possible example of a MAN.

WAN – Wide Area Network is designed to connect multiple offices from multiple cities together, think across country offices. 

Network Topologies

I don’t think I need to spend too much time here as the topology and their names aren’t all that important. But it’s good to know the key players.

The Star topology is often how most home networks are set up. You have a router, that contains the Wifi access point, and all devices connect to that single device in order to communicate.

The Tree topology is what you are more than likely going to see in the workforce. It’s essentially, and I might get some pushback on this, takes a bunch of star topologies and stacks them on top of each other. All your devices connect to a switch, all your switches connect to a router, and all your routers connect to your firewall.

The mesh topology is where all devices are connected to each other. Mesh networking is being talked about more and more these days with the Zero Trust model and decentralizing our networks for better security. But, you can also have mini meshes throughout your network to help with any sort of downtime by using mesh for redundancy. If all of your switches are connected to each other, then if one fails the others could pick up the traffic.

Networking Device Components

A lot of the networking devices can be summed up by what layer they work at. What does that mean? If you want to learn more about layers see my Understanding the OSI Model blog where I walk through the basics of the OSI and what layers are. As well as see my What are Network Devices – Deeper Dive blog for a deeper explanation of these components.

When thinking of a layer 1 and the physical layer, electrical impulses, the devices we can think of is the HUB. The hub is basically a dead device in networking, you would be HARD PRESSED to find any network with a hub in it. What a hub does is replicate all packets that it receives on a port to all other ports that are connected to it, without a care as to if it should repeat that packet.

This word collision is important for our next network component, the SWITCH. The switch works on layer 2 and effectively breaks the collisions up by enabling the traffic to only go to the destined machine via use of the MAC Address, which is the address of that devices port that is connected to the switch. There are such things as a layer 3 switch, but for today we will consider the switch a layer 2 device only. This is one of the two main components, in my head, that makes a network, a network.

The second main component that makes the network a network is the ROUTER. The router works on layer 3 and effectively breaks up the broadcast domains. This device is how your devices from inside get to anywhere in the world.

Network Protocol Components

There are many protocols that make the network go round if you will. Let’s talk about the 3 big ones that we use every single day without thought behind it.

IP – Internet Protocol is how all devices on layer 3 talk to one another. Without an IP no traffic will know where to go.

DNS – Domain Name System was created so that all humans don’t need to know that 1.2.3.4 is the IP address for cloudflare.com (its not but go with it) because we can’t or don’t want to remember that. All you need to know is that cloudflare.com is going to get you to Cloudflare. DNS translates our human URL thoughts to Networking IP thoughts.

HTTP(S) –  HyperText Transport Protocol (Secure) is how all web pages are designed to give us the graphical experience we see when we navigate to cloudflare.com. It does this by requesting and receiving the data from the website that we are contacting. The S is the secure part of this that uses certificates to encrypt that traffic through the internet but outside the scope of this discussion.

Why is this important?

Understanding the basics of networking is, again my opinion, an essential part of any work in the security/cyber space. If you don’t know how things work and talk, your ability to secure them and more importantly know when something is wrong and how to fix it will be lacking. You are putting yourself at a disadvantage. Networks are never going away. The internet is here to stay, and it is getting scarier by the minute. Understanding networks will put you ahead of others. It can be boring to learn about Routers and IPs, but you won’t regret that you learned it.