🔎Networking 101: The Digital Superhighway Explained – No Tech Jargon, Just Fun!"⚙

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Introduction

Have you ever wondered how the internet works? Behind every click, tap, or swipe lies a complex yet fascinating system that connects devices and delivers information instantly. This system is called networking, and it’s the backbone of everything we do online.

In this blog post, we’ll break down the basics of networking in a way that’s easy to grasp, even if you’re just starting out. By the end, you’ll understand how data moves on a network, you’ll also understand how network devices perform their functions which all makes the internet what it is.

What is a Host?

Host is any device that sends or receives traffic on a network e.g. laptop, desktop, phone, printers, servers, cloud services, TVs, speakers, smart watches, refrigerators, IOTs etc.

There are two categories of hosts

(A) Clients and (B) Servers

Note that servers can sometimes also become clients. For example if a web server wants to update some of its files/software from another server (maybe an FTP server) . The web server becomes the client in this case while the FTP becomes the server.

What is an IP Address?

IP Address is the identity of each host on a network. Every host must have an IP Address before it can communicate on a network. IP Address is like a unique number that can only belong to a particular host on a network, meaning two hosts cannot have the same IP Address. There are two types of IP Address (I) IPv4 Address (II) IPv6 Address. All the examples in the blog will use IPv4 addresses.

An IPv4 Address is a 32 bit number which is broken down into 4 octets of 8 bit in each OCTET.

For example xxxx.xxxx.xxxx.xxxx

IPs are assigned hierarchically.

To illustrate this better, let’s say we have a fictional company called CITIBANK with offices in three different locations: Nigeria, Kenya and Ghana.

CITIBANK owns any IP that starts with 10.xx.xx.xx (in other words, 10.anything).

Offices in different locations can have their own hierarchy. There might be different teams in different locations and these teams will have their own dedicated IP space too.

The breaking down of IP Addresses into their different hierarchies(sub-networks) is done through a process called SUB-NETTING.

Understanding Networks

A network is a logical grouping of hosts that require similar connectivity. Let's take two classrooms for example. A biology class and a Computer science class. The biology class devices require a simple internet connectivity while the computer science class requires both internet connection and access to other cloud resources to aid their studies. This means that it would make sense to group these two classes' devices into two separate groups(networks) because of their different connectivity requirements.

Networks share IP address space which means that the devices/hosts in the network are going to be similar (to understand this you need to know subnetting which we won't discuss in this article)

A network is what transports traffic between two hosts. Anytime you connect two hosts (e.g. computers) with a cable, you have a network.

Before networks (interconnection of computers), to move data from one computer to another you need a disk to physically copy the file physically from one host to the other.

Therefore, a network is a logical grouping of hosts with similar connectivity requirements.

Note: networks can contain other networks called sub-networks. Networks can also connect to other networks (Inter-networking). Infact, the internet is just a bunch of different networks connected together (school networks, company networks etc.). These connections are powered by ISPs (Internet Service Providers).

As said earlier, anytime you connect two computers with a cable, you have a network. When you try to establish communication between these two devices, data travels across the wire(cable). Data travelling across a wire decays as it travels long distances. For example if the two computers joined together by a cable are located in two separate buildings, as it travels longer distances it begins to decay and eventually the data is lost before it gets to its destination host. If the two hosts connected by a cable are located in the same room, for example the data might not decay as the data would travel from the source host to the destination host faster.

In order for the data to get to their destination host when they travel a longer distance a network device called REPEATER is used.

REPEATER

A repeater is a network device that regenerates signals. This allows communication between hosts that spans greater distances. This prevents signal from decaying before getting to the destination.

Now let's imagine we now have more than 2 different hosts i.e. more than 2 computers connected on with a wire.

Connecting hosts directly to each other doesn’t scale, it can congest the network very quickly and it is also difficult to maintain. This is how it will look if we try to connect 5 hosts directly to each other in order to build a network.

We can place a network device in the center of these devices and that device can handle communication among all hosts on the network. This way it’s easier to add more hosts on the network and it’s scalable and easier to maintain.

The devices at the center of these hosts that facilitate communication are: Hub, Bridge, Switch and Router.

HUB

Hubs are multiport repeaters. If a host sends a packet the hub simply regenerates the signal across all ports. The problem here is that every host receives other host’s data.

For example if host A sends a packet to host D other hosts receive the packet.

BRIDGES

Bridges sit between hub connected hosts. Bridges only have two ports. One port facing a set of hub connected hosts and the other posts facing another set of hub connected hosts.

Bridges would then learn which hosts are on which side of the bridge. This will help the bridge to contain communication to only the side that is necessary.

For example if host B sends data to host A the hub is going to regenerate the signal across all ports which means that the bridge is going to get a copy of that signal/data. The bridge knows that the destination host of the data is still in the same group therefore the data will not be sent to the other side of the bridge.

If a host A sends data to host F the bridge knows that the destination host is on another network therefore it’ll allow the signal to pass through the bridge to the destination host. Bridges help devices to contain communication to their relative networks.

SWITCHES

Switch is a very important device in modern day networking. A Switch is like a combination of hub and bridge. Switches are like hubs because many devices can connect to the switch and they are like bridges because they can learn which host is connected to which port.

One key thing to note about switches is that they facilitate communication on a port to port basis.

For example if host A wants to send a packet to host D the switch knows exactly which port D is located and it sends the packet to host D without involving other hosts in that communication.

Note: Switch is a device that facilitates communication WITHIN a network.

For example one switch can facilitate communication within the hosts of the biology classroom and another switch will facilitate the communication within the computer science classroom.

What if a host in the computer science classroom wants to speak with another host in the biology classroom and we have established that switches handle communication within a network. For this communication to happen we need another device that can handle communication BETWEEN networks.

ROUTER

Router is a device that facilitates communication BETWEEN networks. At the least the router may also need to connect with the ultimate network of networks which is the internet.

Router provides a good traffic control point for data travelling between networks. Control here means performing security, redirecting and filtering.

If two hosts on different networks want to communicate, since they have to pass through the router it will be a good point to add security policies, filtering of traffic or even redirecting the traffic.

Traditionally, switches could not perform such filtering but there are modern switches with such functionalities.

The way routers work is that they learn which network that they are attached to i.e. they learn the IP Address space of each interface of the network they are connected to. The knowledge of each of these different networks is known as ROUTE and all these routes is stored in what is known as a ROUTING TABLE by the router.

Therefore a Routing Table is all the network that a router knows about. The router is going to use the routing table to distribute/route traffic through the appropriate interface.

A router learns which network they are attached to by having an IP address in that network which serves as its gateway in and out of that network. Gateway also means each hosts way out of their local network.

For example if host A (172.16.22.32) wants to speak to host F(172.16.32.102) which is on a different network it knows that it has to go through a router and the IP Address of that router is stored as the host default gateway.

Routers actually create the hierarchy in networks and even the entire internet. From our earliest example of CITIBANK we saw how networks are laid out for easy scalability to enhance router/switch connectivity.

Note:

• Routing is the process of moving data between networks

• A router is a device whose primary purpose is to perform routing

• Switching is the process of moving data within a network

• A switch is a device whose primary purpose is to perform switching.

Other types of network devices that we won’t discuss in this article

• Access Points - Firewalls - Load Balancers

• Virtual Switches - IDS/IPS - Proxies

• Virtual Routers

All of these devices perform either routing/switching or both.

CONCLUSION

And that’s a wrap on the basics of networking! We’ve explored how data travels, network devices and how they perform their function in what makes the internet such a seamless part of our lives. But guess what? This is only the first stop on our journey. In future posts, we’ll unravel more mysteries – ARP Protocols, OSI Model, TCP/IP, the dreaded SUBNETTING and how to keep your online activities safe from cyber threat actors. Whether you’re a tech newbie or just curious about the digital world, this blog will keep things simple, engaging, and packed with “aha!” moments. So, stay tuned – the best is yet to come, and you won’t want to miss it! 🌐✨