CCNP Network Assurance Practice Test 4 — 15 Questions

Question 1

A network engineer is implementing QoS on a WAN link to prioritize voice traffic. Which queuing mechanism provides the lowest latency for real-time traffic?

Accepted Answer

Low Latency Queuing (LLQ). LLQ is correct because it combines strict priority queuing with CBWFQ, ensuring that voice traffic (marked with EF or CS5) is dequeued before any other traffic class. This strict priority mechanism guarantees the lowest possible latency for real-time traffic, as packets in the priority queue are always transmitted first, regardless of congestion on the WAN link.

Answer

Weighted Random Early Detection (WRED)

Answer

Class-Based Weighted Fair Queuing (CBWFQ)

Answer

First-In, First-Out (FIFO)

Question 2

A network administrator is troubleshooting a BGP routing issue where routes from an eBGP neighbor are not being installed in the routing table. The 'show ip bgp' output shows the routes are received but not valid. What is the most likely cause?

Accepted Answer

The next-hop IP address is not reachable.. For a BGP route to be considered valid and installed in the routing table, the next-hop IP address must be reachable via an IGP or a static route. If the next hop is not reachable, the route will appear in the 'show ip bgp' output but will be marked as not valid (often with a 'r' for received but not valid). This is the most common cause when routes are received from an eBGP neighbor but not installed.

Answer

The AS-path contains the local AS number.

Answer

BGP synchronization is enabled.

Answer

The maximum-prefix limit has been exceeded.

Question 3

A network engineer is designing a multicast network for IPTV. Which protocol is used by routers to discover which multicast groups are of interest to directly connected hosts?

Accepted Answer

Internet Group Management Protocol (IGMP). IGMP is the protocol used between hosts and their directly connected routers to signal membership in multicast groups. When a host wants to receive traffic for a specific IPTV multicast stream, it sends an IGMP membership report, and the router uses this information to build its multicast forwarding state for that subnet. Without IGMP, the router would have no way of knowing which groups are of interest to local hosts.

Answer

Rendezvous Point (RP)

Answer

Protocol Independent Multicast (PIM)

Answer

Multicast Source Discovery Protocol (MSDP)

Question 4

Which TWO statements are true about IP SLA? (Choose two.)

Accepted Answer

IP SLA can be used with tracking objects to trigger route changes.. IP SLA can be combined with tracking objects and the 'track' command to influence routing decisions. When an IP SLA probe fails or falls below a threshold, the tracked object changes state, which can trigger a route change (e.g., via a static route with a higher administrative distance or a PBR policy). This allows the network to react to network performance or reachability issues automatically.

Answer

IP SLA is only supported on ASR routers.

Answer

IP SLA uses actual user traffic for measurements.

Answer

IP SLA can only measure round-trip time, not one-way delay.

Question 5

Which THREE are common causes of high CPU utilization on a Cisco Catalyst switch? (Choose three.)

Accepted Answer

Broadcast storms. Broadcast storms (A) are a classic cause of high CPU utilization on a Catalyst switch because flooded broadcast frames are punted to the CPU for processing and replication to all ports in the VLAN, overwhelming the control plane. Frequent STP topology changes (D) drive high CPU because each TCN forces the switch to recompute the spanning-tree topology, flush MAC address entries, and process BPDUs, consuming significant control-plane cycles. ACL logging with the 'log' keyword (E) is correct because every matching packet is punted to the CPU to generate a syslog message, and a high volume of matches can saturate the CPU. Excessive hardware switching of packets (B) is not a cause of high CPU since hardware (ASIC) switching is designed to forward packets at wire speed without involving the CPU. Low memory conditions (C) affect memory, not CPU utilization, and are not a common cause of high CPU on a Catalyst switch.

Answer

Excessive hardware switching of packets

Answer

Low memory conditions

Question 6

Refer to the exhibit. An engineer notices that interface resets have occurred. What is the most likely cause of the interface resets?

Accepted Answer

Cable or hardware issue causing link flapping. Interface resets typically indicate that the interface has gone down and come back up, which is most commonly caused by a physical layer issue such as a faulty cable, damaged connector, or hardware problem that leads to link flapping. When the link flaps, the interface counters increment the 'resets' field, reflecting the number of times the interface has been reset due to a loss of carrier or a link state change. This is distinct from errors like CRC or collisions, which do not directly cause the interface to reset.

Answer

CRC errors due to noise

Answer

Collisions on the link

Answer

Interface is administratively down

Question 7

Refer to the exhibit. Which OSPF route type is the default route?

Accepted Answer

External type 2 (E2). The exhibit shows a default route (0.0.0.0/0) being redistributed into OSPF from another routing protocol or static route. By default, OSPF redistributes routes as External Type 2 (E2), meaning the metric does not include the internal cost to the ASBR. The route is not an NSSA type because the area is not configured as a not-so-stubby area, and it is not an inter-area route because it originates outside the OSPF domain.

Answer

Inter-area (IA)

Answer

NSSA external type 2 (N2)

Answer

External type 1 (E1)

Question 8

A network engineer is troubleshooting intermittent connectivity issues between two switches connected via a trunk link. The engineer notices that the port counters show a high number of CRC errors and runts on one side. Which action should the engineer take first?

Accepted Answer

Check the cable and connectors for damage or loose connections.. CRC errors and runts on a trunk link typically indicate a Layer 1 physical-layer issue, such as faulty cabling, damaged connectors, or poor termination. The first and most logical step is to inspect and test the physical cable and connectors, as this is the most common root cause and the easiest to verify before making configuration changes.

Answer

Increase the MTU size on the interface.

Answer

Configure the interface with a different duplex setting.

Answer

Disable Dynamic Trunking Protocol (DTP) on the interface.

Question 9

A network administrator is deploying a new QoS policy to prioritize voice traffic across a WAN link. The policy must ensure that voice packets are not dropped even during congestion, and that bandwidth is guaranteed for voice. Which queuing mechanism should be used for the voice class?

Accepted Answer

Low Latency Queuing (LLQ). LLQ is the correct choice because it combines strict priority queuing with CBWFQ, ensuring that voice traffic is placed into a strict priority queue that is serviced before any other queues. This guarantees low latency and prevents voice packet drops during congestion by allowing the priority queue to be policed to a configured bandwidth limit, while still providing bandwidth guarantees for the voice class.

Answer

Weighted Random Early Detection (WRED)

Answer

Class-Based Weighted Fair Queuing (CBWFQ)

Answer

First-In, First-Out (FIFO) queuing

Question 10

Which TWO STP features are used to improve convergence time after a topology change?

Accepted Answer

UplinkFast. UplinkFast is correct because it enables a switch to immediately use an alternate root port when its current root port fails, bypassing the usual 30-second listening and learning delay. This is achieved by artificially lowering the bridge priority of the switch to trigger a topology change notification, allowing the backup port to transition directly to forwarding. BackboneFast is correct because it reduces convergence time by detecting indirect link failures in the backbone and allowing a switch to expire its Max Age timer (default 20 seconds) immediately, rather than waiting for the full timer to expire, thus speeding up the transition to a new root port.

Answer

Root Guard

Answer

BPDU Guard

Answer

PortFast

Question 11

Refer to the exhibit. An administrator needs to ensure that traffic to 192.168.1.0/24 is forwarded via a different path than traffic to 192.168.2.0/24, even though both routes are learned via OSPF with the same metric. Which action should the administrator take?

Accepted Answer

Add a static route for 192.168.1.0/24 with a lower administrative distance than OSPF.. Adding a static route for 192.168.1.0/24 with a lower administrative distance (e.g., 1) than OSPF (default 110) forces the router to prefer the static route over the OSPF-learned route, even though the OSPF metric is the same. This allows traffic to 192.168.1.0/24 to use a different next-hop (e.g., 10.0.0.1) while traffic to 192.168.2.0/24 continues using the OSPF-learned path via 10.0.0.2, achieving the desired path differentiation without altering OSPF metrics or using complex PBR.

Answer

Configure policy-based routing to match 192.168.1.0/24 and set the next hop to 10.0.0.1.

Answer

Use the 'distance ospf' command to change the OSPF administrative distance for all routes.

Answer

Adjust the OSPF cost on the interface to 10.0.0.2.

Question 12

A company has a network with multiple VLANs connected via a Layer 3 switch acting as the gateway for all VLANs. The network uses Rapid PVST+ for spanning tree. Recently, the network team added a new access switch to VLAN 100. After the switch was connected, users in VLAN 100 experienced intermittent connectivity, and the Layer 3 switch logs show 'SPANTREE-2-ROOTGUARD_BLOCK' messages for the port connected to the new switch. The new switch is intended to provide additional access ports for VLAN 100. The network team ensured that the new switch's configuration is correct for VLAN 100 access. What is the most likely cause of the issue, and what action should be taken to resolve it?

Accepted Answer

Configure the new switch with a higher bridge priority (e.g., 28672) to prevent it from becoming the root bridge.. The issue is that the new switch, intended as an access switch, has a lower bridge priority (or default priority of 32768) than the existing root bridge for VLAN 100. When connected, it becomes the new root bridge, causing topology changes and intermittent connectivity. Root Guard on the Layer 3 switch port detects this superior BPDU and blocks the port to protect the root bridge position. Configuring the new switch with a higher bridge priority (e.g., 28672) ensures it cannot become the root bridge, resolving the Root Guard blocks.

Answer

Change the port configuration on the new switch to access mode for VLAN 100.

Answer

Disable Root Guard on the Layer 3 switch port connected to the new switch.

Answer

Remove the new switch from the network because it is causing a BPDU attack.

Question 13

Which TWO statements about Cisco DNA Center's Assurance capabilities are correct?

Accepted Answer

It uses streaming telemetry to collect data for real-time analytics.. Option A is correct because Cisco DNA Center Assurance relies on streaming telemetry (model-driven telemetry pushed from devices) rather than legacy SNMP polling, enabling near real-time analytics and faster issue detection. Option E is correct because Assurance applies machine learning and baseline analytics to historical data, allowing it to proactively identify trends and predict potential problems before they impact users. Option B is incorrect because Assurance covers both wired and wireless networks, including wireless client onboarding and RF health monitoring. Option C is incorrect because DNA Center is typically deployed as an on-premises appliance (with cloud-managed options like DNA Center in the cloud, but not exclusively cloud-based). Option D is incorrect because Assurance provides far more than health scores, including path trace, client 360 views, and network topology analysis.

Answer

It supports only wired networks and not wireless.

Answer

It is a fully cloud-based solution with no on-premises components.

Answer

It only displays network device health scores and does not provide path tracing.

Question 14

A network administrator is troubleshooting a performance issue in a large enterprise campus network. The network consists of Cisco Catalyst 9300 switches acting as access switches and Cisco Catalyst 9500 switches as distribution. Users on VLAN 10 report intermittent slow file transfers to a server on VLAN 20. The administrator has verified that there are no errors on the links, CPU utilization is normal, and STP topology is stable. The administrator suspects a possible QoS issue. Upon checking the QoS configuration on the access switch, the administrator finds that the default QoS configuration is in place, which trusts the CoS value at the port level. The connected devices are IP phones and PCs; the IP phones mark voice traffic with CoS 5. The server on VLAN 20 is connected to a distribution switch. Which action should the administrator take to most likely resolve the issue?

Accepted Answer

Configure auto QoS for VoIP on the access ports to ensure proper classification and queuing.. Auto QoS for VoIP automatically configures the necessary class maps, policy maps, and trust settings to properly classify and queue voice traffic (CoS 5) while ensuring data traffic is not starved. The default QoS configuration trusts CoS at the port level, but without proper queuing and scheduling, voice and data may compete for buffers, causing intermittent slow file transfers. Auto QoS sets up strict priority queuing for voice and allocates bandwidth for data, resolving the performance issue without manual misconfiguration.

Answer

Apply a policy map that polices voice traffic to 128 kbps to free bandwidth for data.

Answer

Disable QoS entirely on all switches to eliminate any potential QoS-related drops.

Answer

Configure trust DSCP on the access ports to prioritize all traffic based on DSCP values.

Question 15

Drag and drop the steps for the DHCP DORA process in the correct order.

Accepted Answer

Discover, then Offer, then Request, then Acknowledge. DHCP uses Discover, Offer, Request, Acknowledge (DORA) for dynamic address assignment.

Answer

Discover, then Request, then Offer, then Acknowledge

Answer

Offer, then Discover, then Request, then Acknowledge

Answer

Discover, then Offer, then Acknowledge, then Request