CCNP Cisco IP Switched Networks (SWITCH v2.0) Free Practice Test — 30 Questions

Question 1

A network administrator observes that users in a branch office are reporting severe performance degradation and intermittent disconnections when accessing the corporate CRM application. Network diagnostics indicate that the underlying physical and data link layers are stable, with no excessive error rates on interfaces. However, application-level metrics show high packet loss and significant latency for CRM-related traffic. Further investigation on an aggregation switch responsible for routing traffic from the branch office reveals an improperly configured Quality of Service (QoS) policy. This policy, intended to prioritize voice traffic, has an overly stringent rate-limiting action applied to the voice class, causing a substantial number of voice packets to be dropped. This congestion, in turn, is indirectly impacting the performance of the CRM application traffic, which shares the same egress path. Which of the following most accurately describes the primary technical reason for the CRM application\'s performance issues?

Accepted Answer

Inefficient queuing and policing of voice traffic on the aggregation switch, leading to congestion that negatively impacts unrelated application traffic.

Question 2

An IT administrator notices that users in the Engineering department, who are assigned to VLAN 30, are experiencing sporadic network access issues, while other departments remain unaffected. Upon investigation, it\'s determined that the core switch, SW-CORE-A, correctly permits VLAN 30 traffic on its trunk link to SW-CORE-B. However, SW-CORE-B\'s trunk interface is configured to allow only VLANs 10 and 20. What is the most precise command to rectify the connectivity problem for VLAN 30 users without disrupting existing VLAN traffic?

Accepted Answer

switchport trunk allowed vlan add 30

Question 3

Consider a Cisco Catalyst 9300 Series switch in a large enterprise network employing Rapid Per-VLAN Spanning Tree Plus (Rapid PVST+). A critical trunk link connecting two distribution layer switches, SW-DIST-A and SW-DIST-B, experiences a transient flapping condition. During this instability, the Spanning Tree protocol recalculates the topology for VLAN 100. Subsequently, SW-DIST-A becomes the root bridge for VLAN 100. Prior to this event, the optimal path for VLAN 100 traffic utilized a direct link between SW-DIST-A and a core switch. Post-flapping, the network administrator observes that the direct link between SW-DIST-A and the core switch is now in a blocking state specifically for VLAN 100 traffic, forcing it to traverse SW-DIST-B. What fundamental principle of Rapid PVST+ explains this behavior, and why might this rerouting occur even if the link itself is operational?

Accepted Answer

Each VLAN runs an independent instance of STP, allowing for distinct optimal path selections and port states per VLAN, even if a physical link is shared.

Question 4

Consider a large enterprise campus network meticulously designed with Rapid PVST+ across all VLANs. During a routine maintenance window, a core switch experiences a spontaneous failure of a link connecting to an aggregation layer switch. Within milliseconds, the redundant path is automatically activated by the network infrastructure. Which fundamental characteristic of Rapid PVST+ is primarily responsible for the swift re-establishment of connectivity, minimizing packet loss and service interruption for end-users on affected VLANs?

Accepted Answer

The protocol's inherent ability to immediately transition non-edge ports to the forwarding state upon detecting a topology change, leveraging faster timer mechanisms and proposal/agreement exchanges.

Question 5

During a planned network expansion, a junior network administrator connects a new unmanaged switch to two existing distribution layer switches, unaware of the existing Spanning Tree Protocol (STP) configuration. The new switch creates an unintended redundant physical path between these two distribution switches. Shortly after the connection, users report a complete network outage. What is the most probable root cause of this immediate and widespread service disruption?

Accepted Answer

A broadcast storm caused by a Layer 2 loop, disabling network functionality.

Question 6

Consider a network segment where Switch Alpha and Switch Beta are interconnected via a 10 Gbps Ethernet link, and Switch Beta is also connected to Switch Gamma using a 1 Gbps Ethernet link. This configuration is operating under Rapid PVST+ with the default path cost values. A new 40 Gbps Ethernet link is then introduced directly between Switch Alpha and Switch Beta. What is the most likely immediate consequence on the forwarding status of the links between Switch Alpha and Switch Beta, assuming Switch Gamma is the root bridge for the VLAN in question?

Accepted Answer

The 40 Gbps link between Switch Alpha and Switch Beta will become the designated path, and the 10 Gbps link between Switch Alpha and Switch Beta will be blocked.

Question 7

A network administrator is configuring a Layer 2 EtherChannel bundle consisting of two 10Gbps links between a distribution switch and a server farm\'s aggregation switch. The primary goal is to ensure optimal traffic distribution from multiple client workstations to a single critical server hosted in the farm. Analysis of network traffic patterns indicates that while the aggregate bandwidth is rarely exceeded, there are instances where one physical link within the EtherChannel appears heavily utilized, nearing its capacity, while the other remains significantly idle. Which of the following EtherChannel load balancing methods is most likely responsible for this observed uneven traffic distribution?

Accepted Answer

Load balancing based on source and destination MAC addresses.

Question 8

Anya, a network engineer, is tasked with upgrading a critical access layer switch in a large enterprise campus network. The existing switch, a Cisco Catalyst 3750, is being replaced with a Cisco Catalyst 9300. Following the physical installation and initial configuration of the new 9300, including basic IP addressing and management access, users begin reporting intermittent connectivity issues. Simultaneously, network monitoring tools begin to flag an increase in broadcast traffic, leading to a noticeable degradation in network performance. Anya, under pressure to restore service quickly, decides to temporarily disable Spanning Tree Protocol (STP) globally on the new switch to mitigate the broadcast storm. This action, however, does not resolve the underlying connectivity problems and introduces new complexities. What fundamental networking principle is most directly violated by Anya\'s immediate action, and what is the primary consequence of disabling STP in this context?

Accepted Answer

Disabling STP removes the network's ability to detect and prevent Layer 2 loops, leading to broadcast storms and unpredictable connectivity, which Anya's action failed to address correctly.

Question 9

A network administrator is troubleshooting a newly deployed 802.1X environment where clients are authenticating successfully but are not being placed into their designated VLANs. Analysis of the switch logs reveals that the RADIUS server is acknowledging authentication, but the switch is not applying any post-authentication policies. The administrator has confirmed that the switch is correctly configured to communicate with the RADIUS server for authentication and accounting. What is the most probable underlying cause for the clients failing to be assigned to their correct VLANs post-authentication?

Accepted Answer

The RADIUS server is not sending the necessary authorization attributes, such as VLAN IDs or tunnel attributes, within its Access-Accept messages that the switch can interpret for dynamic VLAN assignment.

Question 10

Following a significant network disruption where a misconfigured EtherChannel led to cascading link failures and substantial downtime for a global financial services firm, the network engineering team is tasked with re-architecting the core switching infrastructure. The incident highlighted the fragility of the existing design when faced with human error in complex link aggregation configurations. What fundamental network design principles should be prioritized to prevent similar widespread outages in the future, ensuring high availability and rapid recovery from potential misconfigurations?

Accepted Answer

Implement EtherChannel Guard on all EtherChannel interfaces, utilize redundant EtherChannels with diverse physical pathways, and ensure robust Spanning Tree Protocol (STP) configurations including BPDU Guard and Root Guard.

Question 11

A network administrator is configuring a Cisco Catalyst 3850 Series switch to support voice over IP (VoIP) and data traffic. A voice VLAN has been defined and assigned to multiple access ports. During a period of network congestion, a user reports intermittent call quality degradation for non-voice applications while voice calls remain clear. If the switch is configured with a standard QoS policy that prioritizes voice traffic, what is the most likely mechanism ensuring the voice calls maintain clarity and the observed issue with non-voice applications?

Accepted Answer

Low Latency Queuing (LLQ) is prioritizing voice traffic, servicing it before other data classes, thus protecting voice quality during congestion.

Question 12

A network administrator is troubleshooting intermittent connectivity issues impacting a critical business application. The problem appears to be related to a newly configured EtherChannel between two distribution layer switches, SW-DIST-A and SW-DIST-B. The EtherChannel uses LACP and is currently load balancing based on the source and destination MAC addresses. It has been observed that the critical application generates traffic with frequently changing source and destination MAC addresses, even for the same IP-level conversations, leading to an uneven distribution of traffic across the EtherChannel links and subsequent packet drops. Which of the following load balancing methods for the EtherChannel would most effectively address this specific scenario and ensure more consistent traffic distribution?

Accepted Answer

Load balancing based on the XOR of the source and destination IP addresses.

Question 13

Consider a network design where a Cisco Catalyst switch utilizes Rapid Per-VLAN Spanning Tree Plus (Rapid PVST+) and has multiple EtherChannels configured for high-availability and increased bandwidth between core switches. If the Rapid PVST+ instances for several VLANs spanning these EtherChannels do not correctly interpret the bundled links as a single logical entity, what is the most likely consequence on network stability and performance?

Accepted Answer

Each VLAN's Rapid PVST+ instance treats the EtherChannel as a single logical link, ensuring consistent STP states and optimal path utilization across the bundle.

Question 14

Consider a network segment where SW-Access-1 and SW-Access-2, both operating with Rapid PVST+, are interconnected by a primary active link and a secondary redundant link. The primary link is currently carrying traffic. If the secondary redundant link between SW-Access-1 and SW-Access-2 abruptly fails, what is the most direct and immediate impact on the MAC address tables of the switches participating in the same VLANs as the failed link, assuming no loops are immediately created by the failure itself?

Accepted Answer

MAC address tables on switches within the affected VLANs will be flushed to relearn paths.

Question 15

A multinational corporation\'s financial trading platform has been experiencing significant performance degradation, characterized by sporadic packet loss and elevated latency, particularly during periods of high market activity. Network engineers have confirmed that the underlying physical infrastructure is sound and that no widespread hardware failures are present. Analysis of network traffic patterns reveals that the congestion is not due to a complete bandwidth saturation but rather an inability of the network devices to effectively manage competing traffic flows during peak demand. The core issue appears to be that critical financial transaction data is being subjected to the same forwarding treatment as less time-sensitive data, leading to its delay and occasional dropping. Which fundamental network mechanism is most critically absent or inadequately configured to address this scenario?

Accepted Answer

Advanced queuing and traffic prioritization policies

Question 16

Anya, a network engineer, is troubleshooting a persistent, intermittent degradation in a latency-sensitive financial trading application. Initial observations suggest a potential Layer 2 loop or suboptimal path selection within the switched infrastructure, impacting the application\'s real-time data flow. The network utilizes Rapid PVST+ to ensure fast convergence. Anya needs to definitively confirm the Spanning Tree Protocol\'s operational state and decision-making process for the specific links connecting the application servers to the core network to isolate the root cause of the performance issue. Which of the following actions would be the most effective first step in verifying the STP\'s behavior on the suspected problematic segment?

Accepted Answer

Analyzing the `show spanning-tree vlan detail` output on adjacent switches to observe port states and priorities

Question 17

Consider a network design where a Cisco Catalyst switch utilizes an EtherChannel bundle comprising four 1 Gbps links to connect to a core router. A single server, identified by the IP address $192.168.1.100$, is actively communicating with a diverse range of client devices across different subnets, all of which are reachable via the core router. The primary objective is to ensure that traffic originating from this server is distributed as evenly as possible across all four member links of the EtherChannel to maximize bandwidth utilization. If the EtherChannel\'s load-balancing algorithm is configured to use only the source IP address for hashing, what is the most probable outcome regarding the distribution of traffic from this server?

Accepted Answer

Traffic from the server will be distributed unevenly, with all packets likely traversing a single member link within the EtherChannel.

Question 18

A financial services firm\'s critical trading platform is experiencing severe performance degradation, characterized by intermittent transaction failures and high latency. Network engineers have identified that the primary link between two core Cisco Catalyst switches, aggregated via an EtherChannel, is the bottleneck. Upon investigation, it\'s discovered that Switch A\'s EtherChannel is configured to use LACP active mode and a load balancing method based on source and destination MAC addresses. Concurrently, Switch B\'s EtherChannel is configured with LACP passive mode and a load balancing method that considers source and destination IP addresses. Which of the following is the most accurate explanation for the observed network instability and application impact?

Accepted Answer

The EtherChannel fails to form a stable logical link due to incompatible LACP negotiation parameters and disparate load balancing algorithms between the two switches, leading to suboptimal traffic distribution and packet loss.

Question 19

A network administrator is troubleshooting an intermittent connectivity issue in a large enterprise campus network employing RPVST+ across its Cisco Catalyst switches. During a planned maintenance window, a core switch unexpectedly fails, triggering a new root bridge election. A specific access layer switch, which had a port connected to the failed core switch in a forwarding state, now receives superior BPDUs indicating a different root bridge. What is the maximum duration the affected port on this access layer switch might remain in a non-forwarding state as it re-evaluates the network topology and converges to the new STP topology?

Accepted Answer

45 seconds

Question 20

Anya, a network administrator for a growing enterprise, is tasked with enhancing the security posture of their campus network. The current infrastructure utilizes several VLANs for departmental segmentation, including a dedicated VLAN for critical servers. A new security directive mandates that all traffic originating from user VLANs destined for the server VLAN must be inspected by a centralized firewall. Anya needs to implement a solution that ensures inter-VLAN routing occurs at a point where security policies can be effectively enforced, preventing unauthorized access to sensitive server resources. Considering the typical Cisco campus design principles and the need for efficient traffic management and policy enforcement, what is the most appropriate configuration approach to meet this requirement?

Accepted Answer

Configure inter-VLAN routing on a Layer 3 switch, applying Access Control Lists (ACLs) to the VLAN interfaces to filter traffic between user and server VLANs.

Question 21

Following a sudden failure of the designated root bridge in a complex enterprise network utilizing Rapid PVST+, a switch in a remote branch office that previously had a direct, active forwarding path to the original root now finds itself needing to establish a new optimal path to the newly elected root bridge. What is the most likely immediate consequence for the switch\'s port that will ultimately become the new path to the root?

Accepted Answer

The port will transition through blocking states before entering a forwarding state as the new STP topology converges.

Question 22

Following a catastrophic failure of a primary fiber link connecting two Cisco Catalyst 9500 series switches, a secondary redundant link immediately becomes active. Network engineers observe a brief but disruptive network outage characterized by high CPU utilization on the switches and intermittent connectivity issues for end-users. After approximately 45 seconds, normal operations resume. Analysis of the network event logs indicates that the secondary link was transitioning through various Spanning Tree Protocol states for multiple VLANs. Which fundamental network behavior is most likely responsible for the temporary disruption observed by the network engineers?

Accepted Answer

The inherent transient forwarding state of Spanning Tree Protocol during topology change convergence, even with Rapid PVST+ enabled.

Question 23

A network administrator is troubleshooting a critical trunk link between two Cisco Catalyst 9300 series switches, SW1 and SW2, that connects to a core router. Users in several departments report intermittent connectivity and high latency, specifically impacting traffic for VLANs 10, 20, and 30. Basic physical layer checks and IP addressing have been confirmed as correct. The trunk is configured to allow these VLANs. During troubleshooting, it\'s observed that the link\'s behavior fluctuates, sometimes appearing stable for short periods before degrading again. What is the most appropriate configuration step to definitively resolve this issue and ensure stable multi-VLAN traffic flow across the trunk?

Accepted Answer

Explicitly configure the trunk interface on both switches with `switchport mode trunk` and `switchport trunk encapsulation dot1q`.

Question 24

Following a network migration where an EIGRP-speaking segment is being integrated into an existing OSPF routing domain, a network administrator observes that traffic is consistently favoring a particular path that was originally learned via EIGRP, even though other OSPF-learned paths to the same destination exist with seemingly adequate bandwidth. What is the most probable underlying technical reason for this persistent path preference after the redistribution process?

Accepted Answer

The EIGRP metric associated with the preferred path, when converted to an OSPF cost using the default reference bandwidth, results in a lower cumulative cost within the OSPF domain compared to alternative paths.

Question 25

A critical customer-facing application hosted on a server cluster experiences intermittent unavailability, impacting service delivery. The network team has been alerted, and preliminary checks reveal no obvious hardware failures on the server cluster itself. Network engineers are observing unusual traffic patterns but cannot immediately pinpoint a specific misconfiguration or device failure. The organization operates under strict Service Level Agreements (SLAs) that mandate near-continuous availability for this application, with significant financial penalties for prolonged downtime. The team must act decisively to restore service while adhering to best practices for network incident management. Which of the following initial actions best balances the urgency of the situation with a systematic approach to problem resolution?

Accepted Answer

Immediately revert all recent network configuration changes across the entire infrastructure to eliminate potential misconfigurations as the root cause.

Question 26

Anya, a network engineer, is diagnosing a scenario where multicast traffic for a specific group is successfully reaching receivers within the same local subnet but is failing to be delivered to receivers in a remote branch office connected via multiple Layer 3 hops. She has confirmed the multicast source is active, receivers are correctly configured, and PIM-SM is enabled on all relevant interfaces. The network topology includes several distribution layers and inter-subnet routing. What is the most likely underlying cause of this selective multicast delivery failure?

Accepted Answer

An incorrect or unreachable Rendezvous Point (RP) configuration for the affected multicast group, preventing the establishment of the shared distribution tree to the remote branch.

Question 27

Consider a scenario where network administrators at "QuantumLeap Solutions" are observing sporadic disruptions in network connectivity affecting numerous client workstations across several distinct VLANs. Concurrently, the primary distribution switch, a Cisco Catalyst 9500 series, is reporting significant and unusual spikes in its CPU utilization, particularly during these periods of intermittent network access. These disruptions are not isolated to a single subnet or building segment but are widespread, impacting users on VLAN 10 (Sales), VLAN 20 (Engineering), and VLAN 30 (Marketing). The core switch is responsible for inter-VLAN routing.

Which of the following is the most probable underlying cause for these observed network anomalies?

Accepted Answer

A broadcast storm is overwhelming the switch's processing capabilities.

Question 28

Anya, a network engineer at a growing tech firm, is troubleshooting a perplexing issue on their core Layer 3 switch. For several hours after a recent network expansion, inter-VLAN routing between newly created VLANs was functioning flawlessly. However, users in VLAN 100 began reporting intermittent connectivity to resources in VLAN 200. Anya verified IP addressing, subnet masks, and default gateway configurations on the affected hosts and the switch interfaces, finding no discrepancies. The problem persisted for a short duration before mysteriously resolving itself, only to reappear later. A reboot of the Layer 3 switch temporarily restored full connectivity, but the issue would inevitably resurface. What underlying network service, if experiencing instability or an error state, would most likely explain these symptoms of intermittent inter-VLAN routing failure that is temporarily resolved by a switch reload?

Accepted Answer

HSRP (Hot Standby Router Protocol)

Question 29

A network administrator is tasked with designing a switched network infrastructure that will support high-density wireless access points and a significant volume of Voice over IP (VoIP) traffic. The primary objective is to ensure that these real-time applications experience the lowest possible latency and are resilient to network topology changes, minimizing any disruption to voice calls and wireless client connectivity. The existing network utilizes a mixture of Layer 2 access switches and Layer 3 distribution switches, with a single, unified STP domain. Considering the need for rapid convergence and the impact of link failures on real-time data streams, which Spanning Tree Protocol variant would be the most suitable choice to implement across the access and distribution layers to meet these stringent requirements?

Accepted Answer

Rapid Per-VLAN Spanning Tree Plus (RPVST+)

Question 30

Consider a scenario where a network administrator is integrating a new access layer switch into an existing campus network. The core distribution layer switch, a Cisco Catalyst 9300, is running Rapid PVST+ across VLANs. A port on this distribution switch, previously in a blocking state due to STP, is now being considered for activation to connect the new access switch. What is the expected behavior of this port as it progresses through the Spanning Tree Protocol states to reach a forwarding state, specifically concerning its processing of Bridge Protocol Data Units (BPDUs) and user data traffic?

Accepted Answer

The port will process BPDUs to determine its role in the Spanning Tree topology but will not forward user data until it has completed the learning phase and is explicitly in the forwarding state.

CCNP Cisco IP Switched Networks (SWITCH v2.0) Free Practice Test — 30 Questions

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