Updated August 10, 2016
This article explains why the VLAN Membership is displayed as trunk on the UDT console when an endpoint is assigned to multiple VLANs.
All UDT versions
The VLAN Membership is displayed as trunk when an endpoint sits on multiple VLANs to indicate that there is more than one VLAN entry for the port. Selecting the Trunk hyperlink will expand the view and show all VLAN IDs.