As campus networks scale, unmanaged collision domains become a significant performance bottleneck. One of the most effective ways to mitigate this issue is through microsegmentation — breaking down large shared domains into smaller, switched segments.
With the widespread adoption of switches like the Catalyst 2900 and 5500 series, we now deploy Layer 2 segmentation using dedicated switch ports per device. This approach eliminates collisions and provides each connected device with a dedicated bandwidth path.
Microsegmentation with VLAN Pruning and Trunking
To prevent broadcast domains from growing uncontrollably, VLANs help isolate traffic. Trunk links carry multiple VLANs between switches, but without pruning, unnecessary broadcast traffic can still flow across the network.
VTP pruning and manual VLAN control on trunks help enforce tighter segmentation. This further reduces the likelihood of collision domain overlap and unnecessary frame propagation.
Best Practices
- Use one switch port per endpoint.
- Segment departments or traffic types with VLANs.
- Enable VTP pruning or manually define VLANs on trunks.
- Monitor interface stats to detect collisions or late errors — they should be zero.
Microsegmentation has become foundational in LAN design, and it’s something we now implement as a standard baseline in any new campus deployment.