In DMF metadata is appended to the packets forwarded by the fabric to a tool attached to a delivery interface. This metadata is encoded primarily in the outer VLAN tag of the packets. By default (using the auto-delivery-strip feature), this outer VLAN tag is always removed on egress upon delivery to a tool. This feature introduces a choice to selectively preserve a packet's outer VLAN tag instead of either stripping all VLANs or preserving all of them.

DMF-8.4.0 VLAN Preservation

In DMF metadata is appended to the packets forwarded by the fabric to a tool attached to a delivery interface. This metadata is encoded primarily in the outer VLAN tag of the packets.

Improvement VLAN Preservation DMF-8.5.0