Cisco 350-401 Implementing Cisco Enterprise Network Core Technologies (ENCOR) Exam Dumps and Practice Test Questions Set 2 Q21-40

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Question 21:

In a Cisco SD-Access fabric, which control-plane function is primarily responsible for mapping endpoint identifiers such as IP and MAC addresses to their corresponding RLOCs, enabling optimized traffic forwarding within the fabric overlay?

A) LISP map-server/map-resolver
B) SXP binding service
C) VXLAN VNI allocator
D) Fabric border node resolver

Answer:

A) LISP map-server/map-resolver

Explanation:

The control-plane architecture in Cisco SD-Access uses LISP as its foundational mapping system, and the map-server/map-resolver role is the critical element that correlates endpoint identity information (such as IP or MAC addresses) to their routing locators, known as RLOCs. This mapping allows fabric devices to dynamically learn where an endpoint resides in the network so that the overlay built using VXLAN can deliver traffic efficiently. Understanding this mapping mechanism is essential because SD-Access separates identity from location, enabling mobility and segmentation that scale far beyond what traditional Layer 2 or Layer 3 architectures could achieve without significant complexity.

The map-server function stores endpoint identity entries learned from edge nodes, allowing any fabric device to query the current location of a client or host inside the fabric. When a packet destined for an endpoint arrives at an edge device, the node may not immediately know the RLOC of the destination. Instead of flooding or performing inefficient lookups, the edge device contacts the map-resolver, which points it to the correct map-server that holds the requested identity-to-locator mapping. This two-part system ensures the entire fabric functions with minimal broadcast traffic and supports highly scalable endpoints.

Option B, SXP binding service, is unrelated because SXP is used in TrustSec deployments to propagate SGT information, not identity-to-locator mappings. This is important in security contexts but not in fundamental SD-Access forwarding. Option C refers to VXLAN VNI allocation, which is necessary for segmentation but does not determine endpoint location. Option D incorrectly suggests that border nodes resolve every mapping, but border nodes only handle north-south communication between the fabric and external networks, not the end-to-end mapping between endpoints inside the fabric.

The map-server/map-resolver combination also supports micro-segmentation and mobility. When devices move between fabric edge nodes, the control-plane updates their RLOC entries without requiring a renumbering or change in identity. As long as the endpoint’s identity remains consistent, the controller updates the mapping databases and distributes the new location to interested nodes. This gives SD-Access a fundamental advantage over traditional campus LAN architectures, where moving a client to a different wiring closet often involved VLAN changes, DHCP renewals, or manual administrative tasks.

The role of the map-server/map-resolver is unique because it abstracts endpoint location from transport. It enables VXLAN-encapsulated traffic to take the shortest path through the fabric based on updated locator mappings. Without LISP as the intelligent mapping mechanism, the SD-Access control-plane could not provide the level of efficiency, scalability, and mobility that defines intent-based networking. This is why mastering LISP concepts is a major focus area in the ENCOR exam blueprint.

Question 22:

Which QoS model in enterprise networks classifies and marks packets as close to the source as possible, ensuring that traffic maintains its assigned priority markings as it traverses multiple network domains?

A) Best-effort forwarding model
B) IntServ model
C) DiffServ model
D) Layer 2 CoS model

Answer:

C) DiffServ model

Explanation:

The Differentiated Services (DiffServ) model is specifically designed to classify and mark packets close to the ingress point of the network, typically at the access layer, so that traffic maintains consistent behavior as it moves through distribution, core, WAN, and data center domains. This marking allows routers and switches across the enterprise to make forwarding decisions based on predefined QoS rules that associate traffic types with priority levels. When a packet is assigned a DSCP value early, the rest of the network can enforce uniform treatment without having to reclassify. This scope makes DiffServ ideal for large-scale enterprise environments where consistent traffic handling is a necessity.

DiffServ is a scalable model that uses traffic classes rather than per-flow reservations, unlike the IntServ model, which requires RSVP to reserve bandwidth for every individual flow. While IntServ offers tight guarantees, it does not scale well in enterprise contexts where tens of thousands of flows may need prioritization. DiffServ avoids this by grouping flows into classes and relying on boundary marking so that traffic keeps its tags throughout the network. This allows for diverse handling, such as expedited forwarding for voice or assured forwarding for business-critical applications.

Option A, the best-effort forwarding model, does not classify traffic at all. This model is the default behavior of IP networks where all packets are treated equally without prioritization. While simple, it cannot support latency-sensitive or mission-critical applications that need predictable delivery. Option B, IntServ, focuses on guaranteeing bandwidth through resource reservation, but it is impractical at scale and rarely used in modern enterprise designs except in very controlled environments. Option D, Layer 2 CoS, applies markings only within a Layer 2 domain and does not extend across routed boundaries without being mapped to DSCP, which means it does not independently solve end-to-end QoS consistency.

The real power of DiffServ lies in its ability to shape network behavior for a wide range of application types without the overhead associated with per-flow reservation systems. When DiffServ marking is done at entry points, such as access switches, wireless controllers, firewalls, or WAN edges, the downstream devices enforce queues, shaping, or policing based on these markings. For example, voice traffic might receive expedited forwarding to minimize delay and jitter, while transactional data receives assured forwarding and bulk data uses standard best-effort queues.

Cisco ENCOR emphasizes DiffServ due to its prevalent use in enterprise QoS configurations. The exam covers classification, marking, queuing, congestion avoidance, and shaping mechanisms that all depend on proper DiffServ implementation. Understanding how DiffServ propagates markings across trust boundaries and how devices interpret those markings is essential for achieving consistent performance across wired and wireless networks. This is why the DiffServ model is the correct answer: it establishes an end-to-end strategy that preserves traffic priority across multiple administrative and geographic boundaries.

Question 23:

In a Cisco IOS XE programmable network, which configuration method allows the network engineer to define device configurations using structured, model-driven schemas that can be programmatically applied through NETCONF or RESTCONF?

A) CLI templating
B) SNMP MIB provisioning
C) YANG-based configuration
D) Syslog-based sets

Answer:

C) YANG-based configuration

Explanation:

YANG is the core data modeling language used in model-driven programmability across Cisco IOS XE and other modern network operating systems. It provides a structured, hierarchical representation of configuration and operational data, enabling devices to expose their capabilities in a predictable, standards-compliant manner. By using YANG models, engineers can programmatically configure devices through NETCONF or RESTCONF, ensuring consistent layouts, reducing human error, and allowing large-scale automation.

CLI templating (Option A) is familiar to many administrators but lacks true structure. While templates reduce repeated typing, they do not enforce schema consistency or enable programmatic validation against device models. SNMP MIB provisioning (Option B) is outdated for configuration purposes because SNMP was designed primarily for monitoring rather than full lifecycle management. Option D, syslog-based sets, is incorrect because syslog only performs event reporting and does not configure devices at all.

YANG-based configuration allows network-wide automation tools such as Ansible, Cisco NSO, and DNA Center to retrieve, validate, and apply structured configuration objects. This supports declarative intent: rather than specifying commands line-by-line, engineers define the desired final state according to YANG schemas, and network tools enforce that state. YANG also enhances interoperability because it adheres to standard models published by IETF, OpenConfig, and vendor-specific bodies, making it easier to integrate multivendor equipment.

ENCOR places heavy emphasis on programmability and automation, so engineers must understand YANG’s role in building model-based APIs and how those APIs replace traditional CLI interactions in modern network designs.

Question 24:

Which routing protocol feature enables OSPF to reduce SPF recalculations by limiting the need to run the full algorithm when only specific parts of the topology have changed?

A) OSPF stub areas
B) Incremental SPF
C) LSA flooding reduction
D) OSPF default route injection

Answer:

B) Incremental SPF

Explanation:

Incremental SPF is a performance optimization technique that allows OSPF to run the shortest-path calculation only for the sections of the topology affected by a change, rather than recalculating the entire topology. This significantly reduces CPU load and convergence time, especially in large or rapidly changing OSPF networks. Instead of performing a full SPF run every time a link flaps or a node goes down, the protocol identifies which nodes and edges are impacted and recalculates only those paths. This is particularly beneficial in enterprise and service provider environments where real-time responsiveness is critical.

Option A, OSPF stub areas, reduces external LSAs but does not reduce SPF computational overhead in the core areas. Option C, LSA flooding reduction, minimizes the number of LSAs sent but does not control how often SPF is calculated. Option D, default route injection, influences routing behavior but has no relevance to SPF computation frequency.

Incremental SPF is important for network stability because frequent full-table recalculations can cause performance bottlenecks. This feature makes OSPF more scalable without requiring significant architectural redesign. In the ENCOR exam, understanding optimization techniques like incremental SPF helps engineers design high-performance OSPF networks.

Question 25:

In a wireless network using Cisco Catalyst controllers, which mechanism helps ensure reliable roaming by enabling clients to maintain the same IP address as they move between APs within the same mobility group?

A) Fast secure roaming
B) Mobility tunneling
C) FlexConnect local switching
D) Rogue containment

Answer:

B) Mobility tunneling

Explanation:

Mobility tunneling is the mechanism that allows wireless clients to retain their IP addresses when moving across APs or controllers within the same mobility group. When roaming occurs, the original controller establishes a tunnel with the new controller, allowing client traffic to continue flowing through the original anchor point. This ensures seamless connectivity for applications that cannot tolerate IP address changes.

Option A, fast secure roaming, focuses on speeding up authentication, not preserving IP addresses. Option C deals with remote site mode and shifts traffic decisions away from controllers, but it does not handle mobility anchoring. Option D is unrelated to roaming and deals with security enforcement.

Mobility tunneling is crucial for applications like voice over wireless, video calls, and real-time services that depend on IP continuity. ENCOR testing includes mobility concepts because modern enterprise networks must deliver uninterrupted connectivity even in dynamic wireless environments.

Question 26:

Which routing protocol is considered most suitable for large-scale enterprise networks that require rapid convergence and scalability?

A) RIP
B) OSPF
C) EIGRP
D) BGP

Answer:

B) OSPF

Explanation:

Open Shortest Path First (OSPF) is widely regarded as a highly suitable routing protocol for large-scale enterprise networks due to several inherent advantages that align with scalability and convergence requirements. Unlike RIP, which relies on hop count and suffers from slow convergence in larger networks, OSPF uses a link-state routing algorithm that maintains a comprehensive map of the network topology in the form of a link-state database. This allows each router to calculate the shortest path to every destination independently using the Dijkstra algorithm, resulting in rapid convergence when network changes occur.

In terms of scalability, OSPF supports hierarchical network design through the use of areas. This segmentation reduces routing table size and limits the propagation of link-state advertisements, making it practical for extensive enterprise environments. The backbone area (Area 0) serves as the central hub, interconnecting all other areas and maintaining routing efficiency. This hierarchical design contrasts with flat protocols like RIP, which flood routing updates throughout the entire network, causing unnecessary bandwidth consumption and slower convergence.

Moreover, OSPF offers multiple features that enhance its suitability for enterprise networks, such as support for equal-cost multipath (ECMP), route summarization, and authentication mechanisms to secure routing updates. ECMP allows for the distribution of traffic across multiple equal-cost paths, enhancing bandwidth utilization and redundancy. Route summarization reduces the size of routing tables, which is critical in enterprise networks with hundreds or thousands of subnets. Authentication protects the integrity of routing information, preventing unauthorized updates from causing network disruptions.

EIGRP, while offering fast convergence due to its Diffusing Update Algorithm (DUAL), is Cisco-proprietary and, although scalable within Cisco environments, does not have the same standardized deployment and interoperability benefits as OSPF. BGP, on the other hand, is primarily used for inter-domain routing and is more suitable for connecting enterprise networks to multiple ISPs or for large-scale WAN environments, rather than internal routing within an enterprise. RIP is limited to smaller networks because it only supports a maximum hop count of 15 and converges slowly.

From a practical deployment standpoint, OSPF also supports both IPv4 and IPv6, providing future-proofing as enterprises migrate to dual-stack or fully IPv6 networks. Its deterministic nature ensures that all routers in an area have the same view of the network, which is crucial for troubleshooting and network stability. Network administrators can implement OSPF with fine-grained control over metrics, route redistribution, and policy-based routing, making it extremely versatile.

In summary, OSPF combines scalability, fast convergence, hierarchical design support, and robust features that are critical for large enterprise networks. Its ability to efficiently manage large routing tables, segment networks into areas, and provide redundancy and load balancing makes it the most suitable choice when compared to RIP, EIGRP, or BGP for internal enterprise routing. Therefore, option B is the correct choice.

Question 27:

Which of the following technologies provides both Layer 2 and Layer 3 virtualization in a data center network?

A) VLAN
B) VXLAN
C) STP
D) EtherChannel

Answer:

B) VXLAN

Explanation:

Virtual Extensible LAN (VXLAN) is a modern network virtualization technology designed to extend both Layer 2 and Layer 3 capabilities in large-scale data center networks. Traditional VLANs are limited to 4096 identifiers, which restricts scalability in multi-tenant environments, particularly when enterprises and service providers need to isolate hundreds of thousands of tenants. VXLAN overcomes these limitations by encapsulating Layer 2 Ethernet frames within Layer 3 UDP packets, thereby enabling Layer 2 networks to be extended over Layer 3 IP infrastructures.

VXLAN employs a 24-bit segment identifier known as the VXLAN Network Identifier (VNI), which allows up to 16 million unique segments. This vastly increases scalability over traditional VLANs. Encapsulation enables Layer 2 adjacency to span geographically dispersed data centers or virtualized environments connected through IP networks, providing both isolation and flexibility for tenants or application overlays. The encapsulation and tunneling mechanisms also facilitate workload mobility, allowing virtual machines (VMs) to migrate across physical hosts or data centers without changing IP addresses, maintaining network continuity.

Another key feature of VXLAN is its integration with EVPN (Ethernet VPN) as a control plane protocol. EVPN provides MAC address learning and distribution using BGP, reducing the need for flooding in VXLAN overlays and improving convergence times. This combination enables VXLAN to operate efficiently at scale while providing full Layer 2 and Layer 3 segmentation.

Traditional Layer 2 technologies like VLANs provide segmentation within a single broadcast domain, but they lack the ability to natively route traffic or extend across Layer 3 networks. STP (Spanning Tree Protocol) prevents loops but does not provide Layer 3 virtualization. EtherChannel aggregates multiple physical links for bandwidth and redundancy but is not a virtualization technology.

VXLAN also addresses operational challenges in modern enterprise data centers, such as multi-tenancy, microsegmentation, and integration with software-defined networking (SDN) controllers. By decoupling the logical network from the physical network, VXLAN allows network architects to implement overlay networks that are independent of underlying hardware topology, providing flexibility for future expansion and automation. Security policies can also be applied at the VXLAN segment level, enabling fine-grained control over traffic within multi-tenant environments.

In conclusion, VXLAN offers a scalable and efficient solution for implementing both Layer 2 and Layer 3 virtualization in data centers, overcoming limitations of VLANs and providing seamless network extensions across large, distributed environments. Therefore, the correct option is B.

Question 28:

Which Cisco feature allows seamless integration of wired and wireless networks while enforcing security policies consistently across the enterprise?

A) Cisco DNA Center
B) Cisco ISE
C) Cisco Prime
D) Cisco APIC

Answer:

B) Cisco ISE

Explanation:

Cisco Identity Services Engine (ISE) is a comprehensive network security policy management platform that enables organizations to implement consistent access control across wired, wireless, and VPN networks. It provides centralized authentication, authorization, and accounting (AAA) capabilities while allowing granular policy enforcement based on user roles, device types, location, and security posture.

In enterprise networks, maintaining consistent security policies across both wired and wireless segments is critical. Traditionally, wired networks have relied on 802.1X authentication for port-based access control, while wireless networks have used WPA2/WPA3 Enterprise authentication methods. Cisco ISE consolidates these approaches, enabling a unified authentication framework for all network access types.

ISE can integrate with Active Directory or other identity sources to ensure role-based access policies. For example, employees may receive full network access, while guests or IoT devices receive restricted access based on pre-defined policies. The platform also provides profiling of devices, which allows the network to dynamically assign policies based on device type, operating system, or compliance state.

Another critical feature of ISE is its posture assessment capability. Devices attempting to connect to the network can be evaluated for compliance with corporate security policies, such as up-to-date antivirus, OS patches, or required configurations. Non-compliant devices can be placed in a remediation network segment until they meet the security standards.

Cisco ISE also integrates with network infrastructure components like switches, wireless controllers, and VPN gateways to enforce policies in real time. Its integration with Security Group Tags (SGTs) enables scalable segmentation and consistent policy enforcement across different types of access points, switches, and routers, without relying solely on traditional VLANs.

Other Cisco platforms like DNA Center focus on network automation and analytics, Prime provides monitoring and management, and APIC is primarily related to data center fabric management with ACI. While they provide complementary functions, they do not enforce consistent security policies across wired and wireless networks at the granular identity and device level that ISE does.

In large-scale enterprise deployments, ISE ensures that user and device authentication, network access, and security policies are consistently applied across all access points, maintaining compliance, reducing risk, and simplifying operational workflows. By consolidating wired and wireless policy enforcement into a single platform, Cisco ISE reduces complexity, enhances visibility, and improves the overall security posture of the enterprise.

Therefore, the correct answer is B.

Question 29:

Which protocol is used to provide secure routing updates between BGP peers over an IP network?

A) OSPF
B) MD5 authentication
C) IPSec
D) HSRP

Answer:

B) MD5 authentication

Explanation:

Border Gateway Protocol (BGP) is the primary exterior gateway protocol used to exchange routing information between autonomous systems (ASes). Because BGP often operates over untrusted networks such as the Internet, it is susceptible to security risks, including route hijacking, session tampering, and spoofing. To mitigate these risks, BGP can use cryptographic authentication methods to ensure that routing updates are exchanged securely between peers.

One common method for securing BGP sessions is MD5 authentication. MD5 provides a message-digest algorithm that generates a hash of the BGP message using a shared secret key configured on both peers. Each BGP message is accompanied by this hash, allowing the receiving peer to verify the authenticity and integrity of the message. If the hash does not match, the message is discarded, preventing malicious or corrupted routing updates from affecting network stability.

MD5 authentication is simple to configure and widely supported across Cisco routers and other vendors’ devices. It ensures that only authorized peers can establish BGP sessions, mitigating risks such as unauthorized route injections or man-in-the-middle attacks. However, while MD5 ensures message integrity and authentication, it does not provide encryption of the BGP payload; for full confidentiality, additional methods like IPSec tunneling would be necessary.

IPSec can secure BGP updates by encrypting the entire session, but it is not the standard method used for routine authentication between peers. OSPF is an internal routing protocol and unrelated to securing BGP, while HSRP is a redundancy protocol for default gateways and does not deal with routing security.

In enterprise or service provider networks, enabling MD5 authentication for BGP sessions is considered a best practice. It ensures that routers only accept routing updates from verified peers, protecting against misconfigurations or malicious attempts to manipulate routing tables. Administrators can configure separate keys per peer, rotate keys periodically, and monitor authentication failures through logs, enhancing both security and operational visibility.

The choice of MD5 authentication represents a balance between security, simplicity, and compatibility. It maintains BGP session integrity without requiring complex encryption or tunneling configurations while providing sufficient protection against common routing threats. For environments where stronger security is needed, MD5 can be combined with IPSec to achieve authentication and encryption simultaneously.

Therefore, the correct answer is B.

Question 30:

Which feature in Cisco devices allows automatic discovery of neighboring devices and builds a network topology map?

A) CDP
B) STP
C) LACP
D) EIGRP

Answer:

A) CDP

Explanation:

Cisco Discovery Protocol (CDP) is a Layer 2 proprietary protocol that allows Cisco devices to automatically discover information about directly connected neighbors. CDP is particularly useful in large enterprise networks for topology mapping, troubleshooting, and network monitoring. By sending multicast advertisements at regular intervals, devices share details such as device type, model, software version, IP addresses, and interface information with neighboring devices.

CDP operates independently of higher-layer protocols, meaning it can function even if IP addressing or routing has not yet been configured. This capability is invaluable during initial network deployment or troubleshooting, as administrators can quickly identify connected devices, verify physical connectivity, and ensure that interfaces are operating correctly.

The information gathered by CDP can be used to generate a comprehensive network topology map. Tools like Cisco Prime or third-party network management systems leverage CDP data to provide visual representations of network connectivity, highlighting relationships between switches, routers, and other infrastructure components. This visualization aids in fault isolation, performance monitoring, and capacity planning.

While STP (Spanning Tree Protocol) prevents loops in Layer 2 networks, LACP (Link Aggregation Control Protocol) manages bundling of physical interfaces for redundancy and bandwidth, and EIGRP is a routing protocol for Layer 3, none of these protocols provide neighbor discovery or topology mapping capabilities. CDP is specifically designed for device discovery and operational visibility.

Security considerations are important when deploying CDP, as it broadcasts information about the device to all directly connected neighbors. In multi-tenant or untrusted environments, CDP can be disabled or restricted to prevent potential information leakage. However, in enterprise-managed networks, the benefits of automatic discovery, simplified troubleshooting, and efficient topology documentation generally outweigh the risks.

By enabling CDP, administrators can quickly identify misconfigurations, monitor device relationships, and maintain an up-to-date view of the network, which is critical for proactive network management and incident response. Its integration with other management platforms makes it a cornerstone feature for enterprise network operations.

Therefore, the correct answer is A.

Question 31:

Which technology enables a single physical switch to support multiple isolated Layer 2 networks for tenants in a data center?

A) VLAN
B) VTP
C) HSRP
D) STP

Answer:

A) VLAN

Explanation:

Virtual Local Area Networks (VLANs) are a foundational technology in enterprise and data center networking, enabling network segmentation and isolation at Layer 2. VLANs allow a single physical switch to logically divide the network into multiple broadcast domains, each operating as an independent logical LAN. This isolation is critical in multi-tenant environments, where different departments, applications, or tenants require separation for security, performance, and administrative purposes.

Each VLAN is assigned a unique VLAN ID, which is included in the Ethernet frame using IEEE 802.1Q tagging. When a switch receives a frame, it examines the VLAN tag and forwards it only to ports that are members of the same VLAN. This ensures that broadcast traffic, multicast traffic, and unknown unicast traffic do not leak between VLANs, maintaining traffic isolation. VLANs also simplify network management by allowing logical grouping of devices based on function or department rather than physical location, making moves, adds, and changes easier.

VLANs support scalability in enterprise networks by providing a mechanism to create multiple broadcast domains without requiring additional hardware. By partitioning a switch into multiple VLANs, organizations can reduce unnecessary traffic, improve network efficiency, and enhance security. They also serve as the basis for advanced features such as Private VLANs, which further isolate devices within a VLAN while maintaining a shared uplink, providing an additional layer of segmentation for sensitive workloads.

VLANs are often integrated with routing protocols through Layer 3 interfaces or switch virtual interfaces (SVIs) to provide inter-VLAN communication. Routing between VLANs is handled by Layer 3 devices such as multilayer switches or routers, enabling efficient communication while maintaining isolation within each VLAN. This hierarchical approach also supports better network design and easier troubleshooting.

Other technologies in the options serve different purposes. VTP (VLAN Trunking Protocol) helps propagate VLAN configuration across switches but does not provide isolation itself. HSRP (Hot Standby Router Protocol) provides gateway redundancy, ensuring high availability but not Layer 2 segmentation. STP (Spanning Tree Protocol) prevents Layer 2 loops but does not create separate broadcast domains.

VLANs are critical in modern enterprise networks, providing traffic isolation, scalability, and flexibility. Their role extends to supporting virtualization environments, where each virtual machine may reside in its own VLAN, ensuring proper segmentation and security policies are enforced. VLANs also integrate with security mechanisms such as 802.1X, where access control policies can be applied per VLAN based on authentication outcomes.

In summary, VLANs allow a single physical switch to support multiple isolated Layer 2 networks for tenants in a data center. They provide traffic isolation, improved efficiency, simplified management, and integration with security and routing policies, making them the correct choice.

Question 32:

Which of the following protocols allows a router to dynamically discover and establish neighbor relationships for IPv6 routing?

A) OSPFv3
B) RIPng
C) EIGRP for IPv6
D) All of the above

Answer:

D) All of the above

Explanation:

IPv6 introduces several new protocols and updates to existing routing protocols to accommodate its expanded address space and unique features. OSPFv3, RIPng, and EIGRP for IPv6 are all examples of protocols designed to support IPv6 networks, and each includes mechanisms for dynamic neighbor discovery and route advertisement.

OSPFv3 (Open Shortest Path First version 3) is the IPv6-specific version of OSPF. It uses the link-state routing algorithm to maintain a complete network topology. OSPFv3 employs the IPv6 multicast addresses FF02::5 (All OSPF routers) and FF02::6 (All OSPF designated routers) to discover neighbors and exchange routing updates. Neighbor relationships are established through hello packets, and routers maintain adjacency only with those neighbors that share matching parameters, such as hello/dead intervals, area ID, and authentication settings. OSPFv3 also separates the routing protocol operation from address family management, allowing multiple instances per link for greater flexibility.

RIPng (Routing Information Protocol next generation) is an extension of RIPv2 for IPv6. Like its predecessor, RIPng uses a distance-vector algorithm with hop count as the metric. RIPng routers send periodic updates to the multicast address FF02::9 to discover neighbors and maintain routes. It maintains neighbor relationships dynamically, adding routes to the routing table as updates are received. RIPng, although simple and widely supported, is generally suited for smaller IPv6 networks due to its limitations in scalability and slower convergence compared to OSPFv3 or EIGRP.

EIGRP for IPv6 is a Cisco-proprietary protocol that extends EIGRP functionality to IPv6 networks. It maintains neighbor tables, topology tables, and routing tables similar to its IPv4 counterpart. EIGRP for IPv6 uses multicast packets sent to FF02::A for neighbor discovery. It dynamically establishes adjacency with directly connected routers and exchanges routing information efficiently using the Diffusing Update Algorithm (DUAL), ensuring loop-free and fast convergence. EIGRP for IPv6 supports features like unequal-cost load balancing, summarization, and authentication, making it suitable for enterprise IPv6 networks.

All three protocols share a common principle: dynamically discovering neighbors on directly connected links and establishing relationships to exchange routing information. The choice among them depends on network requirements. OSPFv3 is suitable for large-scale networks requiring hierarchical segmentation and fast convergence. RIPng works well for small networks with simplicity as a priority. EIGRP for IPv6 offers Cisco-specific optimizations for fast, loop-free convergence in medium to large enterprise networks.

In conclusion, OSPFv3, RIPng, and EIGRP for IPv6 all provide mechanisms to dynamically discover and establish neighbor relationships in IPv6 networks. Their implementations differ in complexity, scalability, and efficiency, but all fulfill the fundamental requirement of dynamic neighbor discovery. Therefore, the correct answer is D.

Question 33:

Which method allows network administrators to centrally manage policies, configurations, and monitoring across an enterprise network using Cisco DNA?

A) CLI-based configuration
B) SNMP monitoring
C) Cisco DNA Center
D) NetFlow

Answer:

C) Cisco DNA Center

Explanation:

Cisco Digital Network Architecture (DNA) represents a comprehensive approach to network automation, assurance, and policy management. Cisco DNA Center is the central management platform that enables administrators to manage, configure, and monitor the entire enterprise network from a single interface. Unlike traditional CLI-based management, which is manual and prone to human error, Cisco DNA Center leverages automation, policy-driven configuration, and analytics to improve operational efficiency, consistency, and network performance.

Cisco DNA Center provides a centralized dashboard for network visibility, allowing administrators to monitor device health, application performance, and user experience. It collects telemetry data from network devices using protocols such as NETCONF, REST APIs, and streaming telemetry. This data is then analyzed to detect anomalies, predict potential failures, and recommend proactive actions, enhancing network reliability.

Policy management is a core feature of Cisco DNA Center. Administrators can define intent-based policies, specifying network access, security controls, quality of service (QoS), and segmentation requirements. These policies are automatically translated into device-specific configurations and deployed across the network, ensuring consistency and reducing configuration drift. Policies can also adapt dynamically based on contextual information such as user identity, device type, application type, and location.

Automation capabilities extend to provisioning and deployment of network devices. Cisco DNA Center supports zero-touch provisioning (ZTP), enabling new devices to be automatically discovered, configured, and brought online without manual intervention. Configuration templates, software image management, and network segmentation can be applied consistently across the enterprise, significantly reducing operational overhead.

Monitoring and assurance features provide continuous visibility into network performance, with AI/ML-based insights for troubleshooting. Administrators can quickly identify root causes of issues, verify policy compliance, and ensure that service-level agreements (SLAs) are met. Integration with Cisco ISE ensures security policies are enforced across both wired and wireless networks.

Other options serve different purposes. CLI-based configuration is manual and decentralized. SNMP provides monitoring but lacks automation and policy enforcement. NetFlow focuses on traffic analysis and reporting but does not manage network configurations or policies. Cisco DNA Center uniquely combines centralized management, automation, policy enforcement, and assurance in a single platform.

In summary, Cisco DNA Center provides a centralized, policy-driven, and automated approach to managing enterprise networks. It enables consistent configuration, proactive monitoring, and assurance across the network, making it the correct choice for centralized management in Cisco DNA environments.

Question 34:

Which wireless standard operates in the 5 GHz band and supports higher throughput compared to 802.11n?

A) 802.11a
B) 802.11ac
C) 802.11g
D) 802.11b

Answer:

B) 802.11ac

Explanation:

802.11ac, also known as Wi-Fi 5, is a wireless networking standard that operates primarily in the 5 GHz frequency band and supports significantly higher data rates and throughput compared to previous standards such as 802.11n. The key advancements of 802.11ac include wider channel bandwidths, higher-order modulation, and multi-user MIMO (MU-MIMO), all of which contribute to improved performance in enterprise and high-density wireless environments.

The 5 GHz band provides more available channels compared to the 2.4 GHz band, reducing interference from other devices such as Bluetooth, microwaves, and legacy Wi-Fi networks. Wider channels (up to 160 MHz) in 802.11ac allow more data to be transmitted simultaneously, increasing overall throughput. Higher-order modulation schemes like 256-QAM enable more bits to be transmitted per symbol, further enhancing performance.

MU-MIMO allows an access point to transmit to multiple devices simultaneously, improving efficiency and user experience in environments with numerous connected clients. This is a significant improvement over 802.11n, which uses single-user MIMO and requires sequential transmission to multiple devices. Additionally, beamforming in 802.11ac improves signal quality by directing RF energy toward clients, enhancing range and reliability.

Earlier standards such as 802.11a also operate in the 5 GHz band but provide lower throughput and lack advanced features like MU-MIMO or wider channel support. 802.11b and 802.11g operate in the 2.4 GHz band, offering lower speeds and being more susceptible to interference. 802.11n operates in both 2.4 GHz and 5 GHz but achieves lower maximum throughput and lacks many of the efficiency features of 802.11ac.

For enterprise deployments, 802.11ac provides high-speed wireless connectivity suitable for video streaming, cloud applications, large file transfers, and high-density environments. Its backward compatibility ensures that older devices can still connect, while new devices take advantage of the performance improvements. The standard’s enhancements in throughput, range, and client handling make it the preferred choice for modern wireless networks.

Therefore, the correct answer is B.

Question 35:

Which method is used to provide redundancy for default gateways in a LAN environment, ensuring continuous network availability?

A) STP
B) HSRP
C) VRRP
D) Both B and C

Answer:

D) Both B and C

Explanation:

High availability for default gateways is critical in enterprise networks to prevent single points of failure that can disrupt connectivity. Two widely used protocols for default gateway redundancy are Hot Standby Router Protocol (HSRP) and Virtual Router Redundancy Protocol (VRRP). Both protocols provide mechanisms to maintain continuous network availability by creating a virtual IP address that serves as the default gateway for hosts on a LAN.

HSRP is Cisco-proprietary and allows multiple routers to share a virtual IP and MAC address. One router is elected as the active router, forwarding traffic for the virtual IP, while others remain in standby mode. If the active router fails, a standby router automatically takes over, minimizing downtime. HSRP supports multiple groups, load sharing across routers, and authentication features to secure control messages.

VRRP is an open standard alternative that provides similar functionality. It elects a master router to handle traffic for a virtual IP address, with backup routers ready to take over if the master fails. VRRP allows interoperability between multi-vendor devices and supports preemption, priority configuration, and advertisement intervals for redundancy.

Both protocols rely on periodic hello messages to monitor the health of the active/master router. Failover is typically seamless, ensuring hosts continue to reach the default gateway without reconfiguration. While STP provides redundancy for Layer 2 loops and path selection, it does not handle default gateway failover. Other methods like static routing alone do not offer automatic failover without additional configuration.

Implementing HSRP or VRRP enhances network resilience and uptime, which is critical in enterprise environments where connectivity interruptions can disrupt applications, business operations, and productivity. Network engineers often combine these protocols with Layer 2 redundancy and load balancing techniques for comprehensive high availability.

In summary, both HSRP and VRRP are effective methods for providing default gateway redundancy in a LAN, ensuring seamless failover and continuous availability. Therefore, the correct answer is D.

Question 36:

Which routing protocol supports both IPv4 and IPv6, uses a link-state algorithm, and is widely deployed in enterprise networks for internal routing?

A) RIP
B) OSPF
C) EIGRP
D) BGP

Answer:

B) OSPF

Explanation:

Open Shortest Path First (OSPF) is a robust and versatile routing protocol widely deployed in enterprise networks to manage internal routing efficiently. One of the core strengths of OSPF lies in its link-state algorithm, which enables rapid and deterministic convergence compared to distance-vector protocols such as RIP. Link-state routing involves each router independently building a complete map of the network topology, known as the link-state database (LSDB). This database is constructed using link-state advertisements (LSAs) exchanged between routers, allowing every router in an area to have an identical view of the network.

OSPF supports both IPv4 and IPv6 through two versions: OSPFv2 for IPv4 and OSPFv3 for IPv6. OSPFv3 extends the protocol to handle IPv6 addresses natively and introduces improvements such as support for multiple instances per link and the separation of the routing process from address family management. This dual support ensures that enterprises can deploy OSPF in dual-stack environments where IPv4 and IPv6 coexist.

Scalability is another key advantage of OSPF. The protocol allows hierarchical network design through the use of areas, with Area 0 acting as the backbone to interconnect all other areas. This segmentation reduces LSDB size, minimizes routing overhead, and improves convergence in large networks. Without hierarchical segmentation, link-state flooding could overwhelm routers and impact network performance, especially in extensive deployments with thousands of devices.

OSPF provides multiple advanced features that enhance enterprise network performance. Equal-cost multipath (ECMP) enables the use of multiple paths simultaneously, distributing traffic across parallel links and improving bandwidth utilization. OSPF also supports route summarization and filtering at area boundaries, reducing routing table sizes and minimizing unnecessary routing updates across areas. Authentication mechanisms within OSPF ensure that LSAs are verified, protecting against unauthorized or malicious updates that could compromise network stability.

When compared to other routing protocols, OSPF offers several advantages in enterprise deployments. RIP, while simple, is limited by a maximum hop count of 15, making it unsuitable for large-scale networks, and it converges slowly. EIGRP provides fast convergence and loop-free routing but is Cisco-proprietary, limiting interoperability in multi-vendor environments. BGP excels at inter-domain routing and connecting multiple autonomous systems but is designed for WAN and ISP-level deployments, making it less practical for internal enterprise routing.

OSPF also integrates seamlessly with modern enterprise network designs, including virtualization, data center overlays, and SDN environments. Its deterministic nature and hierarchical design facilitate troubleshooting and network planning, allowing network engineers to predict routing behavior accurately. Additionally, OSPF supports multiple metrics and policy-based routing options, giving administrators granular control over path selection, traffic engineering, and redundancy.

In summary, OSPF’s support for both IPv4 and IPv6, use of a link-state algorithm, hierarchical scalability, rapid convergence, and robust enterprise features make it the preferred choice for internal routing in large-scale enterprise networks. Its versatility, reliability, and ability to integrate with modern networking solutions confirm that option B is correct.

Question 37:

Which data center technology encapsulates Layer 2 Ethernet frames within Layer 3 IP packets to extend networks across large environments?

A) VLAN
B) VXLAN
C) GRE
D) MPLS

Answer:

B) VXLAN

Explanation:

Virtual Extensible LAN (VXLAN) is a network virtualization technology designed to address the scalability limitations of traditional VLANs and enable large-scale Layer 2 connectivity over Layer 3 infrastructures. In modern data centers, multi-tenant environments require flexible network segmentation to isolate workloads while supporting VM mobility and high-density deployments. VXLAN solves these challenges by encapsulating Layer 2 Ethernet frames within Layer 3 IP packets using UDP tunneling.

The core concept of VXLAN is the VXLAN Network Identifier (VNI), a 24-bit field that provides up to 16 million unique segments, vastly exceeding the 4096 VLAN limitation. Each VXLAN segment operates as an independent Layer 2 domain, allowing virtual networks to be created on top of the underlying physical IP infrastructure. Encapsulation ensures that Layer 2 adjacency can span Layer 3 boundaries, enabling seamless connectivity across data center racks, buildings, or geographically dispersed locations.

VXLAN supports integration with control plane protocols such as EVPN (Ethernet VPN), which provides MAC address learning and distribution through BGP. EVPN reduces the need for flooding in VXLAN overlays, improves convergence times, and enables more scalable deployments. By decoupling the logical network from the physical network, VXLAN allows administrators to create overlay networks that are independent of the underlying topology, supporting network virtualization, automation, and multi-tenancy.

Traditional VLANs provide segmentation but are limited by the maximum number of VLAN IDs and the need for consistent Layer 2 connectivity. GRE (Generic Routing Encapsulation) provides tunneling capabilities but does not inherently provide multi-tenant segmentation or integration with EVPN. MPLS is designed for WAN and traffic engineering applications but is not primarily used for Layer 2 network virtualization within data centers.

VXLAN also improves operational flexibility. Network administrators can implement workload mobility across data centers without changing IP addresses, maintaining connectivity for applications and users. It supports microsegmentation by integrating with security policies, allowing fine-grained access control within each VXLAN segment. Automation and orchestration tools can leverage VXLAN overlays to dynamically provision virtual networks and enforce policies based on user identity, device type, or application requirements.

Performance considerations in VXLAN are addressed through hardware offloading in modern switches and network interface cards (NICs). Encapsulation and decapsulation can be handled efficiently, minimizing latency and maximizing throughput. Additionally, VXLAN supports multicast, unicast, and head-end replication to ensure efficient broadcast, unknown unicast, and multicast (BUM) traffic handling.

In summary, VXLAN encapsulates Layer 2 Ethernet frames within Layer 3 IP packets, enabling scalable network segmentation, multi-tenancy, and seamless Layer 2 extension across large data center environments. Its features make it the preferred choice for modern enterprise networks, confirming that option B is correct.

Question 38:

Which protocol allows consistent identity-based access policies across wired, wireless, and VPN connections in an enterprise network?

A) RADIUS
B) TACACS+
C) Cisco ISE
D) LDAP

Answer:

C) Cisco ISE

Explanation:

Cisco Identity Services Engine (ISE) is a central component of enterprise network security, providing consistent identity-based access policies across wired, wireless, and VPN connections. ISE integrates AAA (authentication, authorization, and accounting) services with device profiling, posture assessment, and policy enforcement to ensure that users and devices are granted appropriate access based on roles, location, device type, and compliance status.

In modern enterprise networks, the diversity of devices—laptops, mobile phones, IoT devices, and virtual machines—requires dynamic and granular access control. ISE addresses these requirements by centralizing policy management. For wired networks, ISE integrates with 802.1X port-based authentication, ensuring that only authorized devices can connect. For wireless networks, it supports WPA2/WPA3 Enterprise authentication methods, maintaining consistent security policies across all access methods. For VPN connections, ISE can enforce role-based access control and posture assessment before granting connectivity.

ISE’s profiling capabilities allow it to identify devices automatically, classifying them by type, operating system, or manufacturer. This information is used to apply tailored access policies, such as granting full network access to corporate laptops while restricting guest devices to a limited VLAN. Posture assessment ensures that devices meet security compliance standards before they can access sensitive resources, reducing risk from compromised or non-compliant devices.

Other protocols or services, while relevant, do not provide the same centralized policy enforcement capabilities. RADIUS is a protocol used for AAA, TACACS+ is used primarily for device administration access, and LDAP is a directory service for user authentication. While these technologies may integrate with ISE, they do not offer the holistic policy, profiling, and enforcement capabilities that ISE provides across all network access types.

ISE also supports Security Group Tags (SGTs), which enable scalable segmentation and policy enforcement throughout the network. These tags allow security policies to follow users and devices across network segments without relying solely on VLANs, providing greater flexibility and reducing operational complexity. Integration with Cisco DNA Center allows administrators to automate deployment and monitoring of policies, ensuring consistent enforcement and reducing manual errors.

Cisco ISE is critical in environments where consistent access control is required across multiple network access technologies. It reduces administrative overhead, strengthens security, and provides visibility and compliance reporting for enterprise operations. By centralizing identity-based policy enforcement, ISE ensures that security is applied consistently, regardless of whether a user connects via wired, wireless, or VPN.

Therefore, the correct answer is C.

Question 39:

Which feature of EIGRP ensures loop-free and fast convergence in large enterprise networks?

A) DUAL algorithm
B) Split horizon
C) Hold timer
D) Route poisoning

Answer:

A) DUAL algorithm

Explanation:

Enhanced Interior Gateway Routing Protocol (EIGRP) is a Cisco-proprietary routing protocol known for its fast convergence, scalability, and loop-free operation. The key feature responsible for these properties is the Diffusing Update Algorithm (DUAL). DUAL allows EIGRP to calculate the shortest path to a destination while maintaining backup routes, ensuring that network changes do not cause loops or prolonged downtime.

DUAL maintains two critical tables: the topology table and the routing table. The topology table stores all learned routes and their metrics, including feasible distance (FD) and reported distance (RD). The feasible distance represents the best path from the local router to the destination, while the reported distance represents the metric advertised by the neighbor router. By applying the feasibility condition, DUAL determines loop-free backup routes that can be activated immediately if the primary path fails.

One major advantage of DUAL is its ability to provide rapid convergence without relying on periodic updates like RIP. When a network change occurs, only affected routes are recalculated and propagated, minimizing bandwidth usage and reducing network instability. Backup routes identified in the topology table allow EIGRP to switch paths immediately without waiting for neighbors to converge, providing near-instantaneous failover.

Other EIGRP features such as split horizon, hold timers, and route poisoning contribute to loop prevention and stability, but they do not provide the same comprehensive loop-free convergence mechanism as DUAL. Split horizon prevents routing information from being sent back to the source interface, hold timers manage neighbor detection, and route poisoning marks failed routes as unreachable, but none individually ensure the combination of loop-free operation and fast convergence that DUAL provides.

DUAL also allows EIGRP to support unequal-cost load balancing, which enables traffic distribution across multiple paths with different metrics while maintaining loop-free operation. This enhances bandwidth utilization and redundancy in large enterprise networks. The protocol supports Classless Inter-Domain Routing (CIDR), route summarization, and authentication, making it suitable for complex enterprise topologies with thousands of routes.

From a design perspective, EIGRP with DUAL offers predictable and stable routing behavior. Network administrators can design hierarchical networks with multiple paths and rely on DUAL to prevent loops while providing fast failover. The ability to maintain a feasible backup route ensures high availability, which is critical for business-critical applications, VoIP, and real-time services.

In conclusion, the DUAL algorithm is the core mechanism that makes EIGRP fast-converging and loop-free, supporting reliable and scalable routing in enterprise networks. Therefore, option A is correct.

Question 40:

Which wireless security protocol provides strong encryption and is considered the standard for enterprise Wi-Fi networks?

A) WEP
B) WPA2-Enterprise
C) WPA-PSK
D) TKIP

Answer:

B) WPA2-Enterprise

Explanation:

Wi-Fi Protected Access 2 (WPA2) Enterprise is the industry-standard security protocol for enterprise wireless networks, offering strong encryption, centralized authentication, and policy-based access control. Unlike WEP or WPA-PSK, which are suitable for home or small networks but vulnerable to attacks, WPA2-Enterprise integrates with IEEE 802.1X authentication and RADIUS servers to provide identity-based access control and robust encryption using AES (Advanced Encryption Standard).

WPA2-Enterprise enables each user or device to authenticate individually using credentials or certificates. This approach prevents unauthorized access and allows administrators to assign access rights and VLANs based on user roles. It supports mutual authentication, ensuring that clients verify the authenticity of the network and vice versa. By using AES-based CCMP encryption, WPA2-Enterprise provides strong confidentiality, integrity, and protection against eavesdropping and replay attacks.

In contrast, WEP is highly insecure due to weak RC4 encryption and predictable initialization vectors. WPA-PSK uses a pre-shared key, which is less secure in enterprise environments because sharing a single password across many users increases the risk of compromise. TKIP (Temporal Key Integrity Protocol) was introduced as a temporary solution for WPA but is now considered obsolete due to known vulnerabilities.

WPA2-Enterprise is compatible with modern wireless LAN controllers, identity services such as Cisco ISE, and supports advanced features like network access control, device profiling, and guest access segregation. Its integration with centralized AAA systems ensures consistent policy enforcement across the enterprise, allowing secure onboarding of employees, contractors, and IoT devices.

From an operational standpoint, WPA2-Enterprise simplifies security management in large-scale deployments. By leveraging RADIUS authentication, administrators can rotate credentials, enforce password policies, revoke access when necessary, and monitor user activity. It also supports roaming between access points without compromising encryption, ensuring seamless connectivity for mobile users.

In summary, WPA2-Enterprise provides strong encryption, centralized authentication, and identity-based access control, making it the standard for secure enterprise wireless networks. Therefore, the correct answer is B.