Hello and welcome back to “What Is: ____” with Fantastic IT, where we break down complicated but critical IT concepts and break them down in a way that even the least technologically literate can understand.

This week, we’re going to look at an often-used and rarely-understood phrase in the world of 2023 IT: the network layer. The network layer is a lot more confusing than it sounds – as with most things in IT – but it’s also arguably the most important element of your day-to-day internet usage.

Every one of us engages with a network layer of some sort every day of our lives – you’re using the network layer to read these words right now, in fact – making it the most important layer of any network, especially for businesses and business owners.

In this article, we’ll cover all the basics of what a network layer is and why it’s important. Let’s get to learning!

What Is The Network Layer in IT?

The network layer, in its simplest, most basic form, is the part of any network (for example, the Internet) that is responsible for overseeing and ensuring the efficient, secure, and consistent transmission of data from one end to the other.

Since what a “network layer” is can be a bit confusing, we need to define some important elements of what a network layer is. Here are some of the key terms when it comes to the Network Layer.

Data Packets

  • A data packet is a unit of data carried by a network.
  • Packets consist of two main parts: the header and the payload. The header contains control information such as the source and destination addresses, while the payload carries the actual data.
  • The network layer is responsible for both creating and routing these packets across networks.

Internet Protocol (IP):

  • Internet Protocol or IP is a protocol used for routing packets across networks.
  • Every device connected to a network is assigned a unique IP address, which helps identify the source and destination of data packets.
  • IP operates at the network layer and is fundamental for internet communication.


  • Routing is the process of determining the path that data packets will take to reach their destination.
  • Routers use routing protocols to find the most efficient path for data packet transmission.


  • Routers are devices that direct data packets along network paths, helping them reach their intended destinations.
  • You probably know it best as that annoying thing in the living room corner that is always flashing an orange light (just us?).

Network Addressing:

  • Network addressing involves assigning unique identifiers (IP addresses) to devices on a network.
  • This is one of the key elements of the network layer – creating unique IDs for data to flow to and from accurately and efficiently.


  • Subnetworks, or subnets, are divisions within a larger network that allow for easier management and improved network performance. Your Internet Service Provider (ISP), for example, is made up of a series of subnets.
  • The network layer manages communication between subnets, ensuring data packets traverse correctly between them.

The network layer plays a vital role in everything on the internet – in fact, it’s probably the most important part of the internet. It’s where the internet actually happens. It’s the system of data routers that send the data packets that make up our digital systems to all the various IPs within the system.

The network layer is where the basic units of information that make up the internet – data packets – are delivered from one end of the internet to the other. The network layer, specifically, is tasked with the responsibility of sending data packets across varying networks to reach their intended destinations. It employs protocols like the Internet Protocol (IP) to accomplish this task.

This layer operates within the framework of the 7-layer Open Systems Interconnection (OSI) model as Layer 3. The OSI model is a conceptual framework used to understand network interactions in seven distinct layers, each with a specific functionality:

  • Layer 1: Physical Layer: The physical connection between devices in the form of cables, servers, and so on.
  • Layer 2: Data Link Layer: Ensures error-free transmission of data between individual data points on the same network.
  • Layer 3: Network Layer: Our topic of discussion – the network layer is of course responsible for data packet transmission between different networks.
  • Layer 4: Transport Layer: Works alongside the network layer, and ensures the reliable transmission of data segments (large sections of packets) between points on a network.
  • Layer 5: Session Layer: Manages sessions or connections between applications.
  • Layer 6: Presentation Layer: Ensures that data is presented in a readable format. This is the UI layer.
  • Layer 7: Application Layer: Interfaces with the software applications.

Key Areas Of The Network Layer

Packet Forwarding and Routing

  • The network layer is crucial for packet forwarding, which encompasses routing through intermediate routers. This layer provides the mechanism for transferring variable-length network packets from a source to a destination host via one or more networks, ensuring that data traverses the correct path even through multiple networks​.

Data Movement Across Networks

  • The most critical function a network layer serves is to move data into and through various networks. A network layer works as a bridge between and within networks, moving data across digital space, and ensuring seamless communication regardless of the network’s architecture​​.

Data Routing Paths for Network Communication

  • The network layer creates a specific, clear roadmap for data, defining routing paths for network communication. It ensures that data reaches the receiving device in an ordered format through logical network paths. This routing is meticulously controlled by the network layer to maintain order and efficiency in data transfer​​.

Switching Connections and Packet-Oriented Services:

  • The network layer also dubbed the packet level, provides defined benefit services for switching connections and packet-oriented services for relaying data packets. The data transmission choreographed by the network layer encompasses the entire communication network, including the key responsibility of routing between and within network nodes to ensure smooth data transfer between devices and users​.

What Business Owners Need To Know About The Network Layer

For business owners, understanding the network layer is pivotal for ensuring operational efficiency and cybersecurity. Not only will a well-established, robust, network layer increase operational efficiency for anyone connecting to your network, but it also prevents the crushing consequences of cyberattacks that can cost companies millions of dollars for even the smallest breach.

Here are some of the simplest, most direct things you can do to facilitate an efficient and well-protected network layer (and therefore an efficient and well-protected business!)

The Basics Of Network Layer Security For Businesses

  • Develop A Cybersecurity Strategy: A well-rounded cybersecurity strategy is pivotal for small businesses to shield against growing cybersecurity threats. It’s not just about protecting the business but also safeguarding customers’ data, which in turn, builds trust and upholds the business reputation​.
  • Know Your Network Infrastructure: Before diving into security measures, it’s crucial to have a comprehensive understanding of the network infrastructure. Knowing the hardware and software components that comprise the network is the first step toward securing it against potential threats​.
  • Monitor Your Systems Constantly: Keeping a close eye on network traffic is essential to identify any unusual activity that might signify a security threat. Monitoring the traffic coming in and going out of the firewall, and reviewing the reports meticulously, helps in the early detection of potential security issues​.

Essential Security Measures For Any Network Layer

When it comes to network layer security, there’s a few tried-and-true methods and tools that even the most skilled, advanced IT expert uses daily. These are the go-to guardians of your network layer, covering 99% of cases, for both business and personal use.

  • Firewalls and VPNs
    • Firewalls help monitor, control, and restrict network traffic based on predetermined security rules. This provides a line of defense against potential hacks or cyberattacks.
    • Virtual Private Networks (VPNs) provide security by creating a secure channel for data to pass through. In many cases, VPNs also disguise the physical location of anyone using a VPN.
  • Encryption
    • Encrypting sensitive data is a crucial security measure, and can be set up on physical systems or can be established digitally. Hard drive encryption protects data wherever it resides, be it cache or application data, thereby ensuring that sensitive information remains inaccessible to unauthorized users​.
  • Network Intrusion Detection
    • Network Intrusion Detection Systems (NIDS) monitor the network for malicious activities or policy violations and provide reports, enabling timely intervention and mitigation of threats
  • Regular Audits and Assessments
    • Regular network security assessments help in identifying vulnerabilities and ensuring that the security measures in place are effective in safeguarding the network. Usually, this is done with the assistance of your internal IT team or an external managed service provider.
  • Endpoint Security
    • Integrating endpoint security to protect network endpoints like PCs, mobile devices, and other network-connected devices is increasingly becoming one of the most important initiatives businesses can take on to secure their network layer.
  • Consult An Expert
    • Sure, we may be the teensiest bit biased, but we really can’t recommend consulting with a licensed, trained IT professional to sort out your network layer, both to protect your assets from cyberattacks and to optimize your systems for maximum efficiency. Nobody does this better than someone who knows IT in and out.

Secure Your Network Layer and Reap The Rewards

That’s it for this edition of “What Is____”! We hope you have at least a basic understanding of what the network layer is – and why it’s so dang important!

If you haven’t invested substantial resources into securing all aspects of your network layer, we have to recommend you do that – right away. The network layer is where many attacks originate or propagate so making sure your end-to-end network is safe and reliable is step 1 for any business looking to tighten up their cybersecurity.

Additional Reading

OSI – The OSI Model Layer 3
Techopedia – Network Layer