# Go back one pageGo to the next page#Go to this book's Index

Accepting tagged and untagged frames

In a Passport switch, whether or not tagged frames are sent or received is configured at the port level. Tagging is set as true or false for the port and applied to all VLANs on that port. You can select whether or not to discard:

The default is not to discard the frames. You can also designate the port-based VLAN to which these frames are assigned by setting the tagged port's default VLAN ID (the default is VLAN 1). This port-based VLAN must be in spanning tree group 1.

A Passport switch port with tagging enabled is a port from which all frames sent are tagged. You can configure a tagged port to discard untagged frames or to associate them with a VLAN. In the latter case, when an untagged frame is received on a tagged port, it is sent to the user-specified VLAN.

A port with tagging disabled is a port that does not send tagged frames. If a tagged frame is forwarded out a port with tagging set to false, the switch removes the tag from the frame before sending it out the port. When a port with tagging set to false receives a frame, you can configure it to discard tagged frames or to associate them with the VLAN specified in the tag.


Note Note: To optimize performance, on untagged ports in configurations where you do not expect to see tagged frames, you should set DiscardTaggedFrames to true. However, on untagged ports for interconnecting switches, it is probably a better choice to set DiscardTaggedFrames to false. That way, if you should convert an interswitch port from an untagged port to a tagged port, you do not
lose connectivity.

To set a port to discard tagged frames it receives:

  1. From the device view, select a port.
  2. From the Device Manager menu bar, choose Edit > Port.
  3. The Port dialog box opens with the Interface tab displayed.
  4. Click the VLAN tab.
  5. The VLAN tab opens.
  6. In the VLAN tab, check the box entitled DiscardTaggedFrames.
  7. Click Apply.

Go back one pageGo to the next page##Go to this book's Index