300-640 Exam Dumps - Implementing Cisco Data Center AI Infrastructure (DCAI)

Priority Flow Control is a foundational mechanism used to provide lossless Ethernet behavior for RoCEv2. PFC operates on individual Ethernet priorities and allows a congested receiver or switch to pause transmission for the affected priority while permitting traffic in other classes to continue. Cisco's AI networking guidance explicitly states that PFC is enabled for RoCEv2 traffic to prevent packet drops caused by congestion.

This characteristic is critical for RDMA workloads because packet loss can trigger retransmission behavior and significantly degrade GPU collective communication performance. In an AI backend fabric, RoCEv2 is normally placed in a no-drop QoS class with PFC configured for that traffic class. ECN is commonly used alongside PFC to provide proactive congestion signaling, but PFC is the mechanism that directly prevents loss when buffers approach critical utilization.

Traffic shaping in option A may moderate burst rates but does not establish lossless transport. A high DSCP marking in option C provides classification and forwarding preference, not loss prevention. Weighted fair queuing in option D allocates scheduling bandwidth but also does not guarantee that packets will not be discarded during congestion.

Study Guide Reference: 3.1.a Congestion control mechanisms — PFC, ECN, ETS; 3.1.b RoCE/RoCEv2; 3.1.c QoS.

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Configuring an email address as a notification endpoint is not sufficient by itself. Cisco Nexus Hyperfabric requires the recipient endpoint to undergo email verification . After an email endpoint is created, Hyperfabric sends a verification code; the administrator must enter that code and confirm that the endpoint status is verified and active. An unverified address therefore causes the condition described in option B.

The endpoint must also be associated with a notification policy . Cisco documents that assertion notifications are configured by selecting one or more fabrics and one or more notification endpoints in the notification policy. If the relevant fabric and the newly created email endpoint are not paired in the policy, assertion messages are not sent to that address. This makes option C correct.

Options A and E incorrectly assume that Hyperfabric directly uses the organization's own email server. Nexus Hyperfabric provides the notification service through its controller architecture. Option D similarly does not represent the required notification configuration described by Cisco.

The correct operational workflow is therefore: create the email endpoint, complete verification, then associate the desired fabric and endpoint through the notification policy.

Study Guide Reference: AI Infrastructure Operations and Troubleshooting — Hyperfabric monitoring, assertions, notification endpoints, and notification policies.

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hardware profile dlb

dlb-interface all

mode flowlet

The exhibit shows materially uneven utilization across the eight interfaces, with receive utilization ranging from approximately 32.5% to 75.3%. Cisco Dynamic Load Balancing addresses this problem by considering current path utilization rather than relying exclusively on static ECMP hashing.

The configuration begins with hardware profile dlb, which enters the DLB hardware-profile context. dlb-interface all enables DLB on all eligible Layer 3 physical interfaces. Cisco documents both an explicit interface list and the all keyword for this purpose. The document's supplied drag-and-drop answer then selects mode flowlet. Cisco defines flowlet load balancing as the default DLB mode, in which forwarding decisions use Dynamic Resilient Ethernet metrics to select less-loaded paths while maintaining packet ordering within a flowlet.

Cisco also supports per-packet DLB, which can produce even greater path utilization but can reorder packets. When NVIDIA adaptive-routing capabilities are explicitly enabled and endpoints can handle reordering, Cisco documents per-packet DLB as an optimized alternative. That additional prerequisite is not stated in this question.

Therefore, the source-derived configuration is DLB / all interfaces / flowlet .

Study Guide Reference: AI Infrastructure Deployment and Data Management — Dynamic Load Balancing, ECMP optimization, AI backend fabrics, and traffic distribution.

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Cisco Intersight provides comprehensive infrastructure monitoring that extends beyond conventional CPU and memory health reporting to AI accelerator visibility and performance telemetry . Cisco's current Intersight material specifically highlights GPU performance visibility, resource-utilization trends, power consumption, device health, and Metrics Explorer as important capabilities for managing AI-ready infrastructure.

This makes option D the only answer that addresses all three requirements: direct GPU visibility, detection of resource bottlenecks, and overall compute health. Monitoring GPU utilization, memory consumption, power, and associated platform telemetry allows operators to determine whether an AI workload is constrained by the GPU itself or by supporting compute, memory, networking, storage, or thermal infrastructure.

Option A incorrectly characterizes an Intersight Analyze capability as an AI container and Kubernetes deployment engine. Option B identifies valuable complementary network telemetry through Nexus Dashboard, but the question asks specifically for the most critical Intersight capability for monitoring GPU-centric UCS infrastructure. Option C is contradicted by current Cisco capabilities because Intersight provides AI-accelerator and GPU-performance visibility rather than being restricted to basic CPU and memory telemetry.

Study Guide Reference: AI Infrastructure Operations and Troubleshooting — Cisco Intersight health monitoring, GPU telemetry, resource utilization, bottleneck identification, and AI infrastructure optimization.

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Cisco Intersight's automated OS installation workflow requires the operating-system installation media to be available through the Software Repository and an appropriate OS configuration source to supply unattended-install parameters. Cisco's UCS X-Series installation workflow first adds an OS image link to the Software Repository and subsequently selects an OS configuration file during the installation wizard.

The configuration file contains or exposes variables needed for unattended deployment, such as hostname, IP addressing, gateway, DNS configuration, credentials, and other operating-system installation parameters. Cisco also supports validated configuration templates for supported operating systems, depending on the deployment mode and OS version.

A firmware policy is not an OS-installation prerequisite; firmware lifecycle configuration is separate from installation of the guest operating system. A virtual KVM policy is likewise unnecessary for an unattended Cisco Mode installation.

A Server Configuration Utility can be relevant to certain Intersight installation workflows and older/standalone platform procedures, but the question specifically asks for the Cisco Mode prerequisite pair represented by the available choices. The combination of the OS image and operating-system configuration file is therefore the intended answer.

Study Guide Reference: AI Infrastructure Deployment and Data Management — Cisco Intersight automated provisioning, Software Repository, and operating-system deployment.

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