Enabling NVIDIA Spectrum-X Adaptive Routing on Nexus 9000

300-640 By islever Editorial Last updated

Configure high-performance networks to support AI workloads using Cisco Data Center

Short answer

C Include switch configuration “hardware profile spectrum-x” in global configuration mode.

Question

An engineer deploys an AI fabric on Cisco Nexus 9000 Series Switches connected to Cisco UCS nodes with NVIDIA GPUs. The requirements call for optimal network performance for training workloads. Adaptive routing is enabled on the NICs, and per-packet load balancing is enabled on the switches. Which other configuration must be implemented for this integration to be fully operational?
  1. Add the “adaptive-routing” keyword under the switch load balancing configuration.
  2. Set the cisco_dlb=1 option in the NIC configuration so the NIC knows it can use adaptive routing.
  3. Include switch configuration “hardware profile spectrum-x” in global configuration mode. Correct Answer
  4. Include matching statements in your QoS policy so the switch knows which incoming packets to load balance.

Key Takeaways

The exam tests knowledge of specific vendor integration commands for AI workloads; the trap is assuming generic switch load balancing settings are sufficient without enabling the specialized hardware profile.

This question examines the configuration of high-performance AI fabrics on Cisco Nexus switches using NVIDIA Spectrum-X technology. The correct answer is C, as enabling the hardware profile spectrum-x is required to activate adaptive routing features.

Common mistake: Candidates often select option B, believing that NIC-side configuration is the primary step. However, the switch must first be configured to support and enable the specific Spectrum-X protocol before the NICs can utilize it effectively.

Expert Analysis

Why the Answer Is Correct

Correct answer: C — Include switch configuration “hardware profile spectrum-x” in global configuration mode. For NVIDIA Spectrum-X adaptive routing to function correctly with Cisco Nexus 9000 Series Switches, the switch must explicitly enable the feature via the 'hardware profile spectrum-x' command. This command activates the necessary underlying mechanisms for DLB (Dynamic Load Balancing) and ensures the switch understands how to handle packets from Spectrum-X enabled NICs. Without this global configuration, the switch treats traffic normally, ignoring the adaptive routing capabilities.

Why the Other Options Are Wrong

Option A is incorrect because there is no 'adaptive-routing' keyword under standard NX-OS load balancing configurations; the feature is handled by the hardware profile. Option B focuses on the NIC configuration ('cisco_dlb=1'), which is a client-side setting. While important for the endpoint, the question asks for the switch configuration required for the integration to be fully operational at the network level. Option D refers to QoS policies, which are used for traffic classification and prioritization, not for enabling the fundamental adaptive routing load balancing mechanism itself.

Community Comment Notes

Community feedback strongly supports Option C. As SquishyMcG noted, "Enable NVIDIA® spectrum-x adaptive routing. Use the hardware profile spectrum-x command to enable the NVIDIA spectrum-x adaptive routing feature." Wasamela also confirmed that "the hardware profile spectrum-x command must be applied in global configuration mode" to integrate properly with the infrastructure.

Exam Strategy

When configuring AI fabrics, always check if specific vendor integrations (like NVIDIA Spectrum-X or Broadcom Tomahawk) require explicit hardware profiles on the switch. Generic networking concepts often have vendor-specific implementation steps that override standard behaviors.

Frequently Asked Questions

Why is cisco_dlb=1 not the correct answer?

While cisco_dlb=1 configures the NIC, the question asks for the switch configuration required to enable the integration. The switch must have the hardware profile enabled first to process the adaptive routing traffic.

Does hardware profile spectrum-x affect regular traffic?

It primarily affects traffic utilizing the Spectrum-X adaptive routing features. It enables the switch to understand and load balance based on the enhanced packet headers used by NVIDIA GPUs.

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Discussion 2 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 2

  1. SquishyMcG 👍 1 Answered C
    (Optional) Enable NVIDIA® spectrum-x adaptive routing. Use the hardware profile spectrum-x command to enable the NVIDIA spectrum-x adaptive routing feature. When you run this command, the DLB functionality is based on the configuration under hardware profile dlb. https://www.cisco.com/c/en/us/td/docs/dcn/nx-os/nexus9000/106x/configuration/unicast-routing-configuration/cisco-nexus-9000-series-nx-os-unicast-routing-configuration-guide/m-configure-dynamic-load-balancing.html#_nvidia_spectrum_dlb
  2. Wasamela 👍 1 Answered C
    To enable NVIDIA Spectrum-X adaptive routing features and integrate properly with the switch infrastructure, the hardware profile spectrum-x command must be applied in global configuration mode.

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