Virtual Switching Extension (VSX) provides multi-chassis link aggregation, independent control planes, and highly available Layer 2 and Layer 3 forwarding.

Option D describes a topology where VSX at the core can provide redundant Layer 2 connectivity and gateway functions for downstream aggregation devices.

If the aggregation layer operates at Layer 2, the core can terminate VLANs, provide routed interfaces, and deliver resilient forwarding through a VSX pair.

However, this must be distinguished from HPE Aruba Networking's preferred modern three-tier campus architecture.

The official Campus Design Validated Solution Guide recommends a dedicated Layer 3 core with routed connections to the aggregation layer. In that architecture, VSX is normally deployed at the aggregation layer, while the core uses independent routed devices and protocols such as OSPF.

Consequently, option B is not the preferred arrangement because a Layer 3-only core generally does not require VSX to establish redundant routed connectivity.

Option A incorrectly implies that spanning tree is mandatory for VSX LAG operation.

Option C is too absolute because VSX can be deployed in supported designs beyond the standard reference topology.

Option D is the most defensible selection among the available choices, but it describes a conditional design rather than HPE's default three-tier recommendation.

Official HPE Reference: HPE Aruba Networking ESP Campus Design Validated Solution Guide — Three-Tier Campus LAN, Network Resiliency and VSX Pair Placement.

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