Cisco Nexus 9000 integration with NVIDIA adaptive-routing capabilities requires the Nexus switch to enable the Spectrum-X hardware profile . Cisco's current NX-OS configuration guide explicitly specifies the global configuration command hardware profile spectrum-x to enable NVIDIA Spectrum-X adaptive routing. When a Nexus switch peers with a supported NVIDIA NIC, this capability allows the NIC to handle packet reordering created by granular techniques such as per-packet Dynamic Load Balancing.

This is particularly important for AI training because large synchronized RDMA flows can create uneven utilization under conventional hash-based ECMP. Cisco explains that per-packet DLB can spray packets over multiple paths and that NVIDIA adaptive routing/direct data placement enables the receiver to correctly handle packets that arrive out of order, improving utilization and collective-operation performance.

Option A is not the documented NX-OS configuration syntax. Option B is not the Cisco-prescribed Nexus integration command. Option D may be relevant to traffic classification in other designs but does not activate Spectrum-X adaptive-routing interoperability.

Therefore, the Cisco-documented configuration is C. This differs from the supplied file's marked answer B.

Study Guide Reference: 3.0 AI Infrastructure Deployment and Data Management — 3.1.d Load distribution.

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