Access Port vs Trunk Port: The Difference
It comes down to how many VLANs a port carries: an access port carries exactly one VLAN to an end device (a PC, printer), while a trunk port carries many VLANs between switches, tagging each frame with its VLAN ID so the other side knows where it belongs.
Side by side
| Factor | Access Port | Trunk Port |
|---|---|---|
| VLANs carried | One | Many |
| Connects to | End devices (PC, printer, AP) | Switches, routers, other trunks |
| Tagging | Untagged | 802.1Q tags each frame |
| Config | switchport mode access | switchport mode trunk |
| Native VLAN | N/A | Untagged VLAN on the trunk |
The details that matter
An access port is what a normal device plugs into — it belongs to one VLAN and sends/receives untagged frames; the device doesn't even know VLANs exist. A trunk port is the highway between switches: it carries traffic for every VLAN, adding an 802.1Q tag to each frame so the receiving switch can sort it back into the right VLAN. The one exception is the native VLAN, whose traffic crosses the trunk untagged (and must match on both ends). Confusing these — or a native VLAN mismatch — is a top CCNA troubleshooting scenario. Practise in the trunk lab.
Frequently asked questions
What is the difference between an access port and a trunk port?
An access port carries a single VLAN to an end device with untagged frames; a trunk carries multiple VLANs between switches, tagging each frame with 802.1Q.
When should I use a trunk port?
Between switches (or to a router/AP) when multiple VLANs must cross the same link. Use access ports for end devices that belong to one VLAN.
What is the native VLAN on a trunk?
The one VLAN whose traffic is sent untagged across the trunk; it must match on both ends to avoid a native VLAN mismatch.
Related articles
Want hands-on training?
Learn this on real Cisco lab devices with placement support at Attila Technologies, Ahmedabad.