Configure a tagged port to discard all untagged packets so that the frame is not classified into the default VLAN for the port.
default untagged-frames-discard
default untagged-frames-discard port {slot/port[/sub-port][-slot/port[/sub-port]][,...]}
no untagged-frames-discard
no untagged-frames-discard port {slot/port[/sub-port][-slot/port[/sub-port]][,...]}
untagged-frames-discard
untagged-frames-discard port {slot/port[/sub-port][-slot/port[/sub-port]][,...]}
Identifies the slot and port in one of the following formats: a single slot and port (slot/port), a range of slots and ports (slot/port-slot/port), or a series of slots and ports (slot/port,slot/port,slot/port). If the platform supports channelization and the port is channelized, you must also specify the sub-port in the format slot/port/sub-port.
None
GigabitEthernet Interface Configuration