Yes, in a Layer 2 (L2) network where scalability, security, and traffic efficiency are important considerations, it is advisable to deploy a router (or Layer 3 switches) to segment the network into multiple VLANs and perform routing between them. .

This is commonly known as inter-VLAN routing. We explain why this practice is beneficial:

1. Network Segmentation

The use of VLANs allows the network to be segmented into multiple logical subnets, which improves the organization and control of traffic within the network. Each VLAN can act as a separate network, making it easy to manage security policies, control access, and limit broadcast propagation at the network level.

2. Security Improvement

Segmenting the network into VLANs improves security by limiting the scope of broadcast traffic and providing the ability to apply specific security policies to each VLAN. This helps prevent potential threats from spreading freely throughout the network.

3. Efficiency and Performance

By dividing a large network into smaller VLANs, the broadcast domain is reduced. Fewer devices in each broadcast domain means less broadcast traffic, which can significantly improve network performance by reducing the amount of unnecessary traffic each device has to process.

4. Routing between VLANs

To allow communication between VLANs (which are effectively on different subnets), routing must be implemented. This can be accomplished using a router or Layer 3 switches. Routing allows traffic to flow between VLANs as needed, while maintaining segmentation and security between those VLANs.

5. Trunking

Trunking is the process of passing multiple VLANs over a single physical link between switches or between a switch and a router. This is typically done by using the IEEE 802.1Q protocol to “tag” VLAN traffic on the trunk link. Trunking is essential for deploying VLANs across multiple devices, allowing each VLAN to keep its traffic separate and secure, even when traversing the same physical infrastructure.

Conclusion

Deploying a router and configuring VLAN trunking is an effective strategy for managing a Layer 2 network, especially as the network grows in size and complexity. This configuration not only improves security and performance but also offers flexibility in network management, making it easier for administrators to control traffic flow and apply specific network policies.