To create a VLAN segment in NSX, you must create it in a VLAN transport zone and provide a VLAN ID. The NSX documentation states you “set up VLAN transport zones to… connect VLAN segments,” and when creating a VLAN-backed segment you select the VLAN transport zone. The segment creation flow shows “Segment Type: VLAN” with required “VLAN ID” entry and transport zone selection; gateways are not required to merely create a L2 segment. Default gateway IP and Tier-1 attachment are applicable for routed (overlay/T1) use cases, not mandatory for a basic VLAN L2 network; segment profiles can be applied but are not required to create the segment. Thus, the two required actions are selecting the VLAN transport zone and specifying the VLAN ID.