Understanding Your Home Network: A Complete Guide.

#networking #network #networkdevices #cybersecurity

Part 1: The Brain and Backbone: Routers, Switches, and the Devices Running Your Internet

Every day, you video call family across the country, stream shows, and work from home - all at the same time, thanks to the internet. This internet connection is made up of smaller network connections from our individual homes and offices.

In this three-part series, we will explore network devices, wired and wireless connections, and how they work together to enable communication and information sharing.

What devices allow you to connect to your local network and access the internet?

Every network connection depends on devices that keep it connected both locally and over the internet, to share and receive information. These devices that enable these seamless connections are called network devices.

Network devices are physical tools that enable computers and other devices to communicate. Without them, devices would not be able to send or receive information over a network or access the internet. They work behind the scenes to move data from one place to another, make sure information reaches the correct destination, strengthen network signals so connections stay stable, and protect the network from unauthorised access.

Common network devices and their functions

Each network device has a specific role they play in a network connection. Knowing the different kinds of network devices helps you build a network that works well and stays secure. Below is a list of common network devices that play a key role in keeping networks connected and running smoothly.

Hub

A network hub is a basic device that connects multiple computers or Ethernet cables to form a single network segment. When a hub receives data from one device, it sends it to all connected devices without checking where it's actually supposed to go. Because of this, hubs can easily cause network congestion and slow performance, especially when many devices are communicating simultaneously.

Hubs do not filter or manage data traffic, so they lack the intelligence of modern networking devices. Some hubs are passive, simply allowing data to pass through, while active hubs strengthen or regenerate signals before sending them out, acting like repeaters for longer distances. With proper configuration, hubs can handle both digital and analog signals. Because of their limitations and inefficiencies, hubs are rarely used today and have largely been replaced by network switches, which handle data more efficiently and securely.

Modem

A modem (modulator–demodulator) is a device that allows computers to send and receive data over communication lines such as telephone lines or cable systems. It works by converting digital data from a computer into analog signals for transmission, then converting incoming analog signals back into digital data that the computer can understand.

Modems are commonly used to provide internet access for customers of an Internet Service Provider (ISP) and often serve as the connection point between a home or office network and the wider internet. They can come in different forms, including external devices connected via USB or built-in hardware.

Switch

A network switch is a multi-port device that connects multiple devices within a network and sends data only to the intended destination. Unlike a hub, which broadcasts data to every device, a switch uses MAC (physical) addresses to determine exactly where each data packet should go. This makes it faster, more efficient, and more reliable.

Switches support full-duplex communication, allowing devices to send and receive data simultaneously, reducing network congestion and improving performance. They can also help improve network security by controlling access to different parts of the network. More advanced multilayer switches can operate at higher network layers and perform routing, allowing them to act as both switches and routers.

Router

A router is a network device that directs data traffic between networks. It connects two or more networks or subnets and decides the best path for data packets to reach their destination. Routers use IP (logical) addresses and store network information in routing tables to forward data accurately and efficiently.

Routers are intelligent devices that can divide a large internal network into smaller subnetworks, allowing each section to operate independently. They can also be connected to other routers, forming larger and more complex networks such as the Internet. When a router does not know the destination of a packet, it uses information from other connected routers to determine where to send it.
Many routers can filter traffic using access control lists (ACLs) and may function as packet-filtering firewalls, thereby improving network security. Routers support both static routing, which is manually configured, and dynamic routing, in which routers automatically exchange information and select the most efficient path using routing protocols.

Repeater

A repeater is a basic network device that helps data travel longer distances by strengthening and regenerating weak signals. As data travels over a cable or wireless connection, the signal gradually weakens, a process known as attenuation. A repeater solves this problem by restoring the signal so it can continue travelling without loss. They simply receive, amplify, and retransmit signals. While dedicated repeaters are less common today, their functionality is often built into devices like hubs, switches, and routers. They are still sometimes used to extend the range of wireless access points or long network links.

Access point

A wireless access point (WAP) is a network device that allows wireless devices to connect to a wired Ethernet network. It contains a built-in antenna, transmitter, and receiver, and it creates a wireless local area network (WLAN) by acting as a bridge between wireless clients and the wired LAN. Making it possible for laptops, phones, and other wireless devices to access the network and the internet.

To connect to a WAP, devices use a network name called an SSID (Service Set Identifier). The WAP may broadcast this name so nearby devices can easily find the network, or it can be hidden for security reasons, requiring users to enter the SSID manually.

Depending on the area's size and layout, multiple WAPs may be needed to provide full wireless coverage and support more users. The range of a WAP depends on factors such as the wireless standard in use, physical obstacles (Walls, furniture, dense materials), and environmental conditions. Some advanced access points include features such as switching, firewall protection, and DHCP services, making them more versatile network devices.

Firewall

A firewall is a network security device that protects a network by creating a barrier between trusted internal networks and untrusted external networks, such as the internet. It controls how data moves in and out of the network by applying security rules that decide which traffic is allowed and which is blocked.
Firewalls often manage traffic between different network zones, such as the LAN (internal network), WAN (external network), and DMZ (a semi-trusted area for public-facing services). They can also be placed inside an organisation’s network to separate sensitive departments from the rest of the network.
Firewalls can be hardware-based, software-based, or a combination of both. They filter traffic using predefined policies, either allowing most traffic and blocking specific threats (blocklists) or blocking everything except approved traffic (allowlists).
It’s important to note that in most home networks, firewalls are not separate devices. Instead, the router typically includes a basic firewall that blocks incoming internet traffic while allowing devices to connect to the internet.

Conclusion

In conclusion, network devices are what make it possible for our devices to connect, share information, and access the internet safely and smoothly. From simple devices like hubs to routers, switches, Wi-Fi access points, and firewalls, each one helps keep a network running properly. Understanding these basics makes it easier to see how your home or office network works.
In Part Two, we’ll look at network connections, both wired and wireless, and explain how they work with these devices. We’ll also cover how to choose the right connection, how speed affects performance, and how data travels across networks.