Free Practice Questions for Cisco 400-007 Exam

D (High latency):In three-tier architectures, east-west traffic between different pods (access domains) must traverse additional layers (distribution and core), introducing extra hops and thus adding latency. This inefficiency is one reason why spine-leaf architectures are favored for modern data centers.

Other options explained:

A: Bandwidth is less of a concern with high-speed core links.

B: Security is not directly affected by east-west traversal in this architecture.

C: Scalability is limited, but the primary issue for east-west traffic is latency.

A: FabricPath assigns a specific multicast (S,G) flow to one tree. A single (S,G) does not get load-balanced across multiple trees.

E: Overall multicast traffic across multiple (S,G) groups is distributed across multiple FabricPath trees, providing general load balancing and efficient link utilization across the fabric.

Why other options are incorrect:

B: Traffic load per tree may not be uniform due to different group distributions.

C: The assignment is done by the ingress switch based on hashing, not all leaf nodes assign the same tree.

D: Individual (S,G) flows do not get load-balanced across trees.

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The two most common challenges for organizations adopting container technologies are:

B (Security): Containers introduce unique security challenges, such as shared kernels, namespace isolation, image vulnerabilities, and orchestration exposure.

E (Skilled staff): Containerization requires specialized skills in orchestration (e.g., Kubernetes), CI/CD, and microservices design, which may not be readily available in many IT teams.

Other options explained:

A: Performance is generally good for containers; overhead is minimal.

C: Cost savings are often a driver for containerization.

D: Deployment is streamlined via orchestration platforms.

F: Compliance is important but less frequently cited as the initial adoption barrier.

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B (IP Source Guard):IP Source Guard prevents IP address spoofing at Layer 2 by binding IP-to-MAC addresses and filtering unauthorized source IPs. It operates independently of encryption, so it has no impact on encryption performance.

Other options explained:

A: MACsec adds encryption and has performance implications.

C: DHCP snooping with DAI focuses on ARP spoofing, not IP address antispoofing specifically.

D: IPsec handles encryption, which directly impacts performance.

In 802.1d STP, convergence is influenced by hello timer, max_age, and forward_delay.

While hello_timer typically remains at 2 seconds, lowering max_age (default 20s) and forward_delay (default 15s) can speed up convergence.

Forward_delay controls the time spent in listening and learning states; max_age determines how long a BPDU is considered valid before recalculating topology.

Why other options are incorrect:

A, B, D: These timers (transit_delay, bpdu_delay, maximum_transmission_halt_delay) are not directly adjustable parameters in 802.1d implementations.

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Let’s calculate Total Cost of Ownership (TCO) for 24 months based on the table and given scaling requirements:

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Metro Ethernet:

CAPEX = $45,000

Installation Fee = $5,000

OPEX = $125,000/year → $250,000 for 2 years

Total = 45,000 + 5,000 + 250,000 = $300,000

DWDM:

CAPEX = $250,000

Installation Fee = $30,000

OPEX = $100,000/year → $200,000 for 2 years

Total = 250,000 + 30,000 + 200,000 = $480,000

CWDM:

CAPEX = $150,000

Installation Fee = $25,000

OPEX = $100,000/year → $200,000 for 2 years

Total = 150,000 + 25,000 + 200,000 = $375,000

MPLS:

CAPEX = $50,000

Installation Fee = $75,000

OPEX = $150,000/year → $300,000 for 2 years

Total = 50,000 + 75,000 + 300,000 = $425,000

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Metro Ethernet clearly results in the lowest total cost while meeting dual 10G and scalable growth to 20 connections due to its simple provisioning and operational flexibility.

This approach fully aligns with CCDE v3.1 business-driven cost modeling principles: balancing cost, scalability, and operational simplicity.

Why other options are incorrect:

B, C, D: All are more expensive after full 2-year calculation for the required scale.

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D (Python):Python is widely used for network automation, configuration management, and scripting tasks. It simplifies repeatable network changes, validation, and integration with controllers and APIs, reducing deployment time.

Other options explained:

A: LISP is a routing protocol, not an automation tool.

B: Java is a general-purpose language but not commonly used for network automation.

C: " Conclusion " is not a tool.

When both networks use overlapping private IP addresses, a single Cisco IOS NAT router can handle bidirectional NAT with dynamic NAT (overload). However, it requires careful configuration using:

Two distinct NAT pools: One for traffic sourced from side A, and one for traffic sourced from side B.

ip nat inside source and ip nat outside source commands with the overload keyword.

Interfaces must be properly defined with ip nat inside and ip nat outside to reflect traffic directionality.

Option D is correct because it explicitly reflects the requirement to use two different NAT pools for overload in both directions, which ensures proper address translation and session tracking.

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D: Traditional three-tier architectures (access, distribution, and core layers) require that east-west traffic (between servers or pods in different access layers) traverse up to the distribution or core and then back down—introducing unnecessary hops and latency. This is a key design limitation addressed by spine-leaf and fabric architectures.

Other options:

A: Bandwidth may be sufficient but not optimally utilized due to suboptimal pathing.

B: Security is not inherently compromised by architecture, although microsegmentation is harder.

C: Three-tier architectures can scale, but less efficiently and not without trade-offs like latency and complexity.

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A (Distinguishing between config and operational data):NETCONF was designed to provide structured data models (such as YANG), clearly separating configuration from operational state data. SNMP lacks this built-in distinction and generally treats all data as MIB objects.

Other options explained:

B/C/D: Both protocols can perform actions and retrieve or modify data, but only NETCONF natively differentiates config vs. operational state.