In the early days, being able to link every device in a company was quite the revelation. It allowed businesses to share information without the hassle of paperwork.
However, as networks have grown, they have become less easily managed. With hundreds or even thousands of devices connected to a single network, processing power and security became significant concerns. The issue was that anyone with network access could view, download, steal, or sell sensitive company data, causing substantial security concerns.
VLANs, or Virtual Local Area Networks, work by sectioning a local network, allowing devices within each section to communicate exclusively. This segmentation drastically reduces broadcast traffic and significantly enhances data security by restricting unwanted access.
To benefit from VLANs you need to understand how they work. Embracing network segmentation enables you to adopt a more granular, identity-based approach to safeguarding your network.
What Is a VLAN?
A VLAN, is a group of devices that share the same broadcast domain. While this may sound straightforward, VLANs represent a significant advancement over traditional LANs.
A LAN, or Local Area Network, connects computers within a specific area, such as an office. When a broadcast is sent within a LAN, every device on that network must process and accept it. This can put a tremendous load on all connected devices, slow down the entire network, and expose broadcasted data to anyone with network access. As the network grows, this strain on processing power and the lack of security can become unmanageable.
Many businesses have adopted VLANs to address these challenges, which divide a LAN into smaller, distinct segments. Typically, businesses create VLANs for each department, allowing devices within a VLAN to communicate exclusively.
Because VLANs are virtual, they enable secure communication between employees regardless of their physical location. Even when employees are all in the same office, VLANs simplify adding or removing devices from the network without requiring extensive cabling or infrastructure changes, making network management more efficient and secure.
How Does a VLAN Work?
The progression of VLANs came from the limitations of early Ethernet technology. In the 1970s, Ethernet was revolutionary, allowing multiple devices to connect in ways that had never been possible.
However, as more devices joined these networks, significant issues emerged. When multiple devices transmitted broadcasts simultaneously, messages would often become garbled, prompting the development of the first routers and switches.
Even with these advancements, the challenge of constant broadcast traffic persisted. Network performance degraded as more devices were added, and it became clear that limiting networks to a single local area wasn’t a sustainable solution, especially as remote work became more popular. This led to the creation of Virtual Local Area Networks (VLANs).
VLANs logically segment an extensive network into smaller, more manageable networks. Each VLAN operates as an independent network where connected devices can communicate and share broadcasts within their own group.
However, setting up a VLAN involves more than just dividing a business into separate departments. There are often situations where devices on different VLANs need to communicate. For example, a device in one VLAN might need to connect to a scanner or smart TV on another VLAN. At the same time, specific VLANs, like those for customer support and finance teams, may need to be isolated from each other for security reasons.
VLANs manage these interactions through ports, which regulate how subnetworks communicate. When data reaches a switch, the port determines whether to allow the VLAN information to pass through. These ports are classified as “tagged” or “untagged,”
The Difference Between Tagged and Untagged VLAN
VLANs are generally categorised into tagged and untagged. Here’s a closer look at their similarities and differences.
Untagged VLANs
Untagged VLANs, are connected to servers that transmit VLAN information between networks without distinguishing between different VLAN configurations. These VLANs have a straightforward, linear flow of traffic—moving from point A to point B, without branching out to multiple destinations. In most cases, untagged VLANs are the default setup.
Tagged VLANs
Tagged VLANs, allow switch access ports to handle multiple VLANs and direct traffic accordingly. Unlike untagged VLANs, where data moves between two specific hosts, tagged VLANs can distribute with a VLAN tag to numerous hosts connected to different ports based on their configuration. The VLAN tags indicate what data should be sent to specific VLANs on the receiving end.
VLAN Tagging and Network Security
Implementing VLAN tagging may require a more complex setup, but it unlocks a host of powerful network benefits, including:
Enhanced Security: VLAN tags can be integrated into the user authentication, dynamically directing users to the correct VLAN and preventing unauthorised access to other networks. Additionally, VLANs can be used to configure separate firewalls and security protocols based on the sensitivity of the data being transmitted within each tagged VLAN.
Reduced Network Congestion: Unlike untagged VLANs, which are limited by their linear design, tagged VLANs offer superior traffic management. This efficiency leads to better overall network performance and less congestion.
Cost Efficiency: Untagged VLANs often require additional switches to route data effectively, driving up costs. Tagged VLANs, however, optimise traffic direction from the start, reducing the need for extra hardware and lowering overall expenses.
Simplified Troubleshooting and Updates: VLAN tagging provides complete visibility into network traffic, making troubleshooting and resolving issues easier. VLAN tags can be updated quickly, which allows changes without significantly disrupting employee productivity. As a company grows, more tagged VLANs can be added to the network, whether for physical or remote expansion.
Network Segmentation
Network segmentation is a critical strategy for thorough WiFi network security, especially now threats are increasingly sophisticated. VLAN tagging helps organise network traffic, helping switches and routers identify the appropriate VLAN for each packet. This contributes to micro-segmentation within a network, enhancing security and performance by isolating specific devices. Such isolation strengthens control and protects against potential breaches.
Maintaining a separate guest Wi-Fi network is also essential for security, bandwidth management, and convenience. It ensures that your primary network remains secure and focused on work-related activities.
If you need help with VLANs or segmentation of your network, contact us. We have the skills and experience to ensure your network is fully secure and functional.
