VLAN trunking is a method used to send multiple VLANs across a single network link between two switches or devices. Recently, I built a multi-switch VLAN network in Cisco Packet Tracer, connecting different departments while ensuring seamless communication within VLANs. In this article, I'll walk you through the setup, configuration, and successful implementation of VLANs and trunking across multiple switches. Trunking allows traffic from different VLANs on a switch to traverse the same link to another switch while at the same time, providing a method to segment the different user groups. 30) so all three switches have all three VLANS. The VLAN (Virtual LAN) specification is described in the IEEE 802. Why do we need trunk links? Soon after VLANs were introduced.