switchport mode

Use this command to configure the mode of a switch port as access, trunk or general.

In Trunk mode, the port becomes a member of all VLANs on switch unless specified in the allowed list in the switchport trunk allowed vlan command. The PVID of the port is set to the Native VLAN as specified in the switchport trunk native vlan command. It means that trunk ports accept both tagged and untagged packets, where untagged packets are processed on the native VLAN and tagged packets are processed on the VLAN ID contained in the packet. MAC learning is performed on both tagged and untagged packets. Tagged packets received with a VLAN ID of which the port is not a member are discarded and MAC learning is not performed. The Trunk ports always transmit packets untagged on native VLAN.

In Access mode, the port becomes a member of only one VLAN. The port sends and receives untagged traffic. It can also receive tagged traffic. The ingress filtering is enabled on port. It means that when the VLAN ID of received packet is not identical to Access VLAN ID, the packet is discarded.

In General mode, the user can perform custom configuration of VLAN membership, PVID, tagging, and ingress filtering.