Users Guide

Port Characteristics 639
Switchport Modes
Each port on the Dell EMC Networking N-Series switches can be configured
to be in one of the following modes:
• Access — Access ports are intended to connect end-stations to the system,
especially when the end-stations are incapable of generating VLAN tags.
Access ports support a single VLAN (the PVID). Packets received untagged
are processed as if they are tagged with the access port PVID. Packets
received that are tagged with the PVID are also processed. Packets received
that are tagged with a VLAN other than the PVID are dropped. If the
VLAN associated with an access port is deleted, the PVID of the access
port is set to VLAN 1. VLAN 1 may not be deleted from the switch.
Access mode port VLAN membership may be reconfigured dynamically by
protocols such as 802.1X or Voice VLAN. Reconfiguration can change the
PVID (802.1X RADIUS assignment) or allow an additional VLAN (Voice
VLAN) to pass traffic.
• Trunk — Trunk-mode ports are intended for switch-to-switch links. Trunk
ports can receive both tagged and untagged packets. Tagged packets
received on a trunk port are forwarded on the VLAN contained in the tag if
the trunk port is a member of the VLAN. Untagged packets received on a
trunk port are forwarded on the native VLAN. Packets received on another
interface belonging to the native VLAN are transmitted untagged on a
trunk port.
Trunk mode ports are members of all VLANs by default. Administrators
can restrict the VLAN membership of trunk mode ports and may configure
VLANs that do not exist on the switch. Trunk mode port VLAN
membership is generally not reconfigured by protocols beyond adding
newly created VLANs to the port, as allowed by trunk port membership
configuration.
• General — General ports can act like access or trunk ports or a hybrid of
both. General mode port VLAN membership may be reconfigured
dynamically by protocols such as 802.1X, GVRP, MVRP, or Voice VLAN.
Reconfiguration can change the PVID (802.1X RADIUS assignment), or
NOTE: Cable diagnostics may give misleading results if green mode is enabled
on the port. Disable green mode prior to running any cable diagnostics.