Free Cisco 300-540 Exam Dumps September 2026

Comprehensive and Detailed Explanation

SNMP traps in Cisco NFVIS (and in SNMP generally):

Are unsolicited notifications

Sent from the NFVIS device to the SNMP manager

Indicate alarms, changes, or significant operational events

Do not require polling

Examples:

Disk failures

VM crashes

Host status changes

Resource alarms

Why the others are wrong:

A describes SNMP monitoring (done by the manager with GET requests)

B SNMP cannot control host activities

D SNMP GET retrieves a variable, but traps send unsolicited notifications

Thus, the correct answer is C.

Comprehensive and Detailed Explanation

Cisco NFVIS logging levels (from lowest to highest):

critical

error

warning

info

debug highest verbosity

To capture maximum diagnostic detail, engineers must enable debug logging on the operational log type, which records system activity and runtime behavior.

Thus the correct command is:

system set-log logtype operational level debug

This provides the deepest troubleshooting visibility.

In a cloud-scale or data center--scale environment, Virtual Extensible LAN (VXLAN) is used as an overlay technology to transport Layer 2 segments over a Layer 3 underlay network. VXLAN encapsulates Layer 2 Ethernet frames inside UDP/IP packets, allowing broadcast, unknown unicast, and multicast (BUM) traffic and tenant Layer 2 domains to be extended across a routed IP fabric.

Key points aligned with Cisco Service Provider Cloud Infrastructure design principles:

VXLAN creates a Layer 2 overlay on top of a Layer 3 underlay.

The VXLAN Network Identifier (VNI) provides a much larger segmentation space than traditional VLANs, enabling multi-tenancy at cloud scale.

Because the underlay is pure Layer 3 (IP routed fabric), VXLAN allows you to interconnect Layer 2 segments between leaf switches or data centers over an IP/MPLS backbone without relying on large Layer 2 domains in the physical network.

Why the options evaluate as follows:

Option A: extends Layer 2 segments across the underlying Layer 3 infrastructure

This is the core benefit of VXLAN in cloud-scale designs. VXLAN encapsulates Layer 2 frames into IP/UDP headers, allowing isolated Layer 2 segments (per VNI) to be stretched across a routed IP network. This enables:

Multi-tenant Layer 2 connectivity across a distributed cloud fabric

Mobility of virtual machines or containers while keeping same IP/MAC addressing

Use of an IP-based leaf--spine or service provider underlay for scalability and resiliency

Option B: extends Layer 3 segments across the underlying Layer 2 infrastructure

This is the opposite of what VXLAN does. VXLAN is explicitly L2-over-L3, not L3-over-L2. Extending pure Layer 3 segments over Layer 2 is not the VXLAN use case.

Option C: reduces spanning-tree complexity across the Layer 2 infrastructure (Partially related but not the primary or direct benefit)

In modern designs, the underlay is Layer 3 routed, and VXLAN overlays provide logical Layer 2 segments. This design avoids dependence on spanning tree in the fabric, which indirectly reduces STP complexity. However, the fundamental, exam-relevant benefit is L2 extension over L3, so C is not the best or most accurate answer compared to A.

Option D: eliminates the need for a Layer 3 underlay in the service provider infrastructure

VXLAN absolutely requires an IP (Layer 3) underlay for transport. VXLAN tunnels are built over a routed infrastructure (leaf--spine, MPLS/IP core, etc.). It does not remove the need for Layer 3; it depends on it.

For a site-to-site IPsec VPN, each peer must configure a pre-shared key tied to the public IP address of the remote VPN peer:

crypto isakmp key <KEY> address <REMOTE_PUBLIC_IP>

From the diagram:

R1 outside IP: 192.168.10.1/24

R2 outside IP: 192.168.20.2/24 remote peer for R1

In the current R1 configuration, the ISAKMP key is incorrectly bound to 192.168.10.2, which is a local next-hop/ISP address on R1's own subnet, not the R2 public IP. Because the pre-shared-key address does not match the source IP of R2's IKE packets, phase 1 negotiation fails and the tunnel never comes up.

The correct configuration on R1 must therefore be:

crypto isakmp key vpnuser address 192.168.20.2

Options A and C incorrectly change the default route (next hop must be the local ISP router, not R2's public IP or a LAN address). Option D uses an internal address (10.1.1.2), which is not the IP used for IKE on the Internet.

Comprehensive and Detailed Explanation

In Cisco high-availability LAN gateway designs, the requirement is:

Multiple L3 gateways sharing a virtual MAC and virtual IP

Ability to load balance across multiple active gateways

Capability to seamlessly take over gateway forwarding during a failure

Among Cisco First Hop Redundancy Protocols (FHRPs):

HSRP Active/standby only

VRRP Active/standby only

GLBP (Gateway Load Balancing Protocol) The only FHRP providing active/active load balancing

GLBP allows multiple routers to share:

A common virtual IP

Multiple virtual MAC addresses

Multiple active forwarders that load-balance end hosts

Automatic failover if any gateway fails

Thus, GLBP is the only correct protocol matching the requirement for redundant default gateways with load balancing and shared MAC addressing.

Cisco Umbrella DNS-layer security:

Blocks malicious domains used in phishing, malware, C2 communications, and ransomware

Stops threats before connections are made

Uses DNS-based filtering and threat intelligence

It does not mitigate:

DDoS (needs scrubbing centers)

Brute force login attempts

Zero-day exploits directly

Thus, A is correct.

Comprehensive and Detailed Explanation

Infrastructure as Code (IaC) requires:

Declarative configuration

Automation

API-driven workflows

Multi-cloud capability

Integration with orchestration and provisioning tools

Terraform is a widely adopted IaC platform supporting:

Cloud automation (AWS, Azure, GCP, private clouds)

Cisco infrastructure provisioning (Nexus, ACI, IOS-XR, NSO, SD-WAN, etc.)

REST APIs and providers for programmability

Cisco provides official Terraform providers for multiple platforms, enabling full IaC operations. This aligns exactly with SP cloud automation design principles.

Other options:

Cloud-based sandboxes For testing, not IaC automation

ThousandEyes Monitoring and performance analytics

AppDynamics Application performance management

Comprehensive and Detailed Explanation

Cisco Container Platform (CCP), built on Kubernetes orchestration, uses YAML files for:

Cluster configuration

Pod definitions

Network settings

Storage mappings

YAML is the industry-standard declarative syntax for Kubernetes and container orchestration platforms.

HTML, XHTML, and XML are not used for CCP configuration.