350-501 Practice Test 23 — 15 Questions

Question 1

Which THREE technologies or protocols are used to implement automated service provisioning in a Cisco service provider network?

Accepted Answer

Cisco NSO. Cisco NSO provides orchestration and service lifecycle management. NETCONF is used for configuration management. YANG provides data models for configuration and state data. SNMP is for monitoring, not provisioning. RIP is a routing protocol, not for provisioning.

Answer

SNMP

Answer

RIP

Question 2

Refer to the exhibit. Which statement is correct about the LDP bindings for prefix 10.0.0.0/24?

Accepted Answer

There are two remote label bindings for this prefix from different LSRs.. Option B is correct because the local label is 180, and there are two remote bindings from different LSRs. Option A is incorrect; the local label is 180, not 18. Option C is incorrect; the remote labels are from two different peers. Option D is incorrect; there is no implied PHP from this output.

Answer

Both remote bindings are from the same LSR.

Answer

The local label for this prefix is 18.

Answer

The router is performing PHP for this prefix.

Question 3

Refer to the exhibit. An engineer makes a RESTCONF request to retrieve operational data for all interfaces, but the response shows only one interface. What is the most likely cause?

Accepted Answer

The request path includes a specific interface key, filtering the result. The request path includes '/interface=GigabitEthernet0/0/0', which filters the list to that specific interface. To retrieve all interfaces, the path should be '/interfaces' without the key. The YANG model is supported (200 OK), the HTTP method is correct, telemetry and VRFs are irrelevant.

Answer

The interfaces are in different VRFs

Answer

The device does not support the YANG model

Answer

The engineer used the wrong HTTP method

Answer

The collector is not subscribed to telemetry

Question 4

An SP is troubleshooting an MPLS L2VPN VPLS network where MAC flapping is occurring between two PEs. Which mechanism in VPLS prevents loops and ensures that a broadcast frame from one PE is not reflected back to the originating PE?

Accepted Answer

Split horizon. Option D is correct. Split horizon in VPLS means a PE will not forward a frame received from one pseudowire out another pseudowire within the same VFI, preventing loops. Option A (STP) is used at the CE side but not inside the VPLS core. Option B (RSTP) same. Option C (MAC aging) is for learning, not loop prevention.

Answer

Spanning Tree Protocol (STP)

Answer

Rapid Spanning Tree Protocol (RSTP)

Answer

MAC address aging

Question 5

Refer to the exhibit. An engineer configures IP SLA for UDP jitter. The operation completes successfully, but the customer reports voice quality issues. What should the engineer check next?

Accepted Answer

The threshold is set too high. The threshold of 100 ms is too high for jitter monitoring; voice quality typically degrades when jitter exceeds 20-30 ms. With a 100 ms threshold, even if jitter spikes to harmful levels, the SLA does not trigger an alert. The current jitter (5 ms) and packet loss (0%) are fine, but the threshold setting prevents proactive detection.

Answer

The packet loss is 0%

Answer

The frequency is too low

Answer

The jitter value is within threshold

Answer

The destination is unreachable

Question 6

Which TWO of the following are characteristics of Segment Routing (SR-MPLS) compared to traditional LDP-based MPLS? (Select two.)

Accepted Answer

SR-MPLS does not require LDP or RSVP-TE for label distribution.. Options A and E are correct. SR-MPLS uses a segment list (stack of labels) encoded in the packet header, and it does not require LDP or RSVP-TE for label distribution; labels are assigned by the IGP (OSPF or IS-IS). Option B is wrong: SR-MPLS can do traffic engineering via SR-TE policies. Option C is wrong: SR-MPLS supports fast reroute (TI-LFA). Option D is wrong: SR-MPLS can support any label range (16-1,048,575).

Answer

SR-MPLS requires a dedicated label range from 16 to 99.

Answer

SR-MPLS does not support traffic engineering.

Answer

SR-MPLS cannot provide fast reroute protection.

Question 7

A service provider is automating the provisioning of MPLS L3VPNs across multiple devices using NETCONF. During a deployment, the automation script fails with an error indicating that the device does not support the required YANG model. Which action should the engineer take to verify device capabilities?

Accepted Answer

Use the hello message exchange to check supported YANG modules via capabilities.. NETCONF hello message exchange includes the list of supported YANG modules in the capabilities. This is the standard way to discover device capabilities. Other options are either not standard or would not provide the required information.

Answer

Use CLI show command to list YANG models.

Answer

Use RESTCONF with GET to retrieve device capabilities.

Answer

Use SNMP to check device OID.

Question 8

Which TWO of the following are services that can be offered using MPLS Layer 3 VPN (L3VPN) technology? (Select two.)

Accepted Answer

IP transit services. Options A and C are correct. MPLS L3VPN provides Layer 3 connectivity between customer sites; Internet service can be provided via separate VRF or global table; IP transit is a typical Layer 3 service. Option B (Layer 2 bridging) is for L2VPN/VPLS. Option D (Transport of Ethernet frames) is L2VPN. Option E (Multicast support) is possible but is a feature, not a service itself.

Answer

Layer 2 bridging between sites

Answer

Transport of Ethernet frames over MPLS

Answer

Native multicast support without tunnels

Question 9

An SP engineer is configuring model-driven telemetry (MDT) to monitor interface utilization on Cisco routers. The telemetry receiver uses gRPC and is experiencing high CPU load due to excessive subscription data. Which MDT subscription parameter should be adjusted to reduce the data rate without losing critical threshold events?

Accepted Answer

Enable on-change reporting with suppression.. On-change reporting with suppression reduces data rate by sending updates only when values change, and suppression prevents too-frequent updates. Increasing sample interval risks missing threshold events. Other options do not effectively reduce data rate while preserving event detection.

Answer

Use a smaller path XPath.

Answer

Increase the sensor-group period.

Answer

Increase the sample-interval.

Question 10

A service provider deploys MPLS L3VPN to connect multiple customer sites. Which VPN address family must be enabled on the PE routers to exchange customer IPv4 routes between PEs?

Accepted Answer

VPNv4 unicast. Option C is correct because VPNv4 address family carries IPv4 VPN routes with RD and RT. Option A is wrong because IPv4 unicast is for global table. Option B is wrong because VPNv6 is for IPv6 VPNs. Option D is wrong because labeled IPv4 is used for MPLS label distribution.

Answer

IPv4 labeled-unicast

Answer

IPv4 unicast

Answer

VPNv6 unicast

Question 11

A network engineer is using Cisco NSO to create a managed L3VPN service. After deploying the service, the engineer notices that the configuration on the devices is not being updated. What is the most likely cause?

Accepted Answer

The service has not been committed.. In NSO, services are committed to push configuration changes to devices. If the commit is not performed, the changes remain in the candidate database and are not applied. Other options are less likely given the symptom.

Answer

The service model is not compiled.

Answer

The device is not in the device list.

Answer

The sync-from command was not run.

Question 12

A network engineer is troubleshooting slow BGP convergence after a link failure in an MPLS core. Which feature can be enabled on the PE routers to fast-failover traffic upon BGP next-hop unreachability?

Accepted Answer

BGP Prefix Independent Convergence (PIC). Option B is correct because BGP PIC (Prefix Independent Convergence) provides fast failover using backup paths. Option A is wrong because BFD is for fast detection, not convergence. Option C is wrong because Local Pref influences path selection, not convergence. Option D is wrong because Route Reflectors reduce iBGP sessions, not failover speed.

Answer

Route Reflector clustering

Answer

Bidirectional Forwarding Detection (BFD)

Answer

Local Preference manipulation

Question 13

A network architect is designing a model-driven telemetry solution for a large SP network. Which three factors are critical to consider when configuring telemetry subscriptions? (Choose three.)

Accepted Answer

The collection protocol (gRPC vs gNMI vs native TCP).. Network bandwidth to the collector ensures the data can be transmitted without loss. The collection protocol affects performance and feature support. The sampling interval determines data granularity and load. The size of the YANG model is not a subscription configuration factor, and encoding format is a trade-off but not as critical as the others.

Answer

The size of the YANG data model.

Answer

The encoding format (GPB, JSON, XML).

Question 14

Match each MPLS protection mechanism to its description.

Question 15

Match each network automation tool to its primary use.