The VMware Cloud Foundation 9.0 NSX Projects and VPC Guide outlines the prerequisites for configuring external connectivity using a Transit Gateway (TGW). When VLAN-backed external connectivity is used, the documentation specifies:

“For VLAN-backed external connectivity, ensure that all hosts in the workload cluster where VPC workloads run have physical access to the VLAN(s) used by the Transit Gateway. This ensures end-to-end packet reachability between VPC segments and the physical router.”

Analysis of options:

A (TWO BGP Peers): BGP can be configured later to enable dynamic routing but is not a prerequisite for establishing VLAN-backed connectivity.

B (TNP attached): A Transport Node Profile is required for NSX host preparation, but it is part of the general NSX setup, not the specific prerequisite for TGW VLAN external connectivity.

C (Access to VLANs): This is the critical prerequisite—hosts running workloads must have access to the external VLANs. Without this, connectivity to the physical routers will fail.

D (Access to Edge TEP network): TEP networks are used for overlay traffic (Geneve encapsulation), not for VLAN-backed TGW external connectivity.

Therefore, the correct prerequisite is ensuring all VPC workload hosts have access to the VLAN(s) used by the Distributed TGW.