Access Ports and Trunk Links

Once you have VLANs, switch ports come in two main flavors: access ports and trunk ports. An access port carries traffic for a single VLAN and connects to end devices. A trunk port carries traffic for many VLANs at once and connects switches together. Knowing the difference is essential to building any multi-switch VLAN network, and it is a favorite exam topic.

An access port belongs to exactly one VLAN. You plug an end device, a PC, printer, or phone, into it, and that device sits in the assigned VLAN. The device has no idea VLANs exist; it just sends and receives normal frames. The switch quietly associates everything on that port with its single VLAN. Most ports in a building are access ports.