Configure a Tagged Port to Discard Untagged Frames

Configure a tagged port to discard all untagged packets so that the frame is not classified into the default VLAN for the port.

Procedure

  1. Enter GigabitEthernet Interface Configuration mode:

    enable

    configure terminal

    interface GigabitEthernet {slot/port[/sub-port][-slot/port[/sub-port]][,...][slot/all][all]}

    Note

    Note

    If the platform supports channelization and the port is channelized, you must also specify the sub-port in the format slot/port/sub-port.

  2. Configure a tagged port to discard untagged frames:

    untagged-frames-discard [port {slot/port[/sub-port][-slot/port[/sub-port]][,...]}]

  3. Discard a tagged frame on an untagged port:

    tagged-frames-discard [port {slot/port[/sub-port][-slot/port[/sub-port]][,...]}] enable

  4. Untag the default VLAN on a tagged port:

    untag-port-default-vlan [port {slot/port[/sub-port][-slot/port[/sub-port]][,...]}] enable

Example

Configure a tagged port to discard untagged frames:

Switch(config-if)#untagged-frames-discard port 1/1

Discard a tagged frame on an untagged port:

Switch(config-if)#tagged-frames-discard port 1/1 enable

Untag the default VLAN on a tagged port:

Switch(config-if)#untag-port-default-vlan port 1/2 enable

Variable Definitions

Use the data in the following table to use optional parameters with the untagged-frames-discard command.

Variable

Value

{slot/port[/sub-port][-slot/port[/sub-port]][,...][slot/all][all]}

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)

  • a series of slots and ports (slot/port,slot/port,slot/port)

  • all ports on the same slot (slot/all)

  • all ports on the switch (all)

If the platform supports channelization and the port is channelized, you must also specify the sub-port in the format slot/port/sub-port.