350-501 Architecture Practice Test 11 — 15 Questions

Question 1

A service provider is using NSO for service orchestration. Which protocol does NSO use to communicate with network devices for configuration?

Accepted Answer

NETCONF. NSO uses NETCONF as the primary protocol for device configuration, leveraging YANG models.

Answer

SNMP

Answer

RESTCONF

Answer

CLI scripting

Question 2

Which TWO are characteristics of the access layer in a service provider network? (Choose two.)

Accepted Answer

Provides connectivity to end customers. Access layer provides connectivity to end users and aggregates traffic from various technologies.

Answer

Implements inter-AS MPLS

Answer

Uses MPLS label switching for core traffic

Answer

Performs BGP route reflection

Question 3

Which TWO are benefits of using EVPN over traditional VPLS for L2VPN services? (Choose two.)

Accepted Answer

Provides MAC address learning via control plane. EVPN offers better control plane (BGP) and supports multi-homing with all-active load balancing.

Answer

Uses LDP for label distribution

Answer

Requires full mesh of pseudowires

Answer

Simpler configuration than VPLS

Question 4

Which THREE are correct statements about IOS XR process separation? (Choose three.)

Accepted Answer

Processes can be restarted independently without affecting others. IOS XR runs each protocol as a separate process, providing fault isolation and independent restart.

Answer

A failure in one process can crash the entire system

Answer

All processes share a single memory space

Question 5

Which access technology in a service provider network uses a passive optical splitter to distribute signals to multiple customers, with typical downstream speeds up to 2.5 Gbps?

Accepted Answer

GPON. GPON is a point-to-multipoint fiber access technology using passive optical splitters, providing downstream speeds up to 2.5 Gbps and upstream up to 1.25 Gbps.

Answer

Metro Ethernet

Answer

DSL

Answer

Cable (DOCSIS)

Question 6

An SP is deploying MPLS in the core/backbone to support L3VPN services. What is the purpose of MP-BGP in an MPLS VPN architecture?

Accepted Answer

To exchange customer VPN routes and VPN labels between PE routers. MP-BGP (Multiprotocol BGP) carries VPNv4 routes between PE routers, including the VPN label, enabling customer isolation and reachability across the MPLS core.

Answer

To forward data packets across the MPLS core

Answer

To establish IGP adjacencies between PE and CE routers

Answer

To distribute MPLS labels for LSPs

Question 7

An SP uses Cisco ASR 9000 routers with IOS XR. Which statement correctly describes the commit/rollback configuration model in IOS XR?

Accepted Answer

Changes are staged in a candidate configuration and applied only after 'commit'; rollback to a previous commit is possible.. IOS XR requires a 'commit' to apply changes; it supports rollback to previous committed configurations, allowing safe changes.

Answer

Only 'commit replace' is supported; rollback requires manual re-entry.

Answer

The router automatically commits changes every 10 minutes.

Answer

Changes take effect immediately without commit; rollback is not supported.

Question 8

Which Cisco router platform is designed for the core/backbone of a service provider network, supporting high-density 100GE interfaces and massive scale for MPLS and Segment Routing?

Accepted Answer

Cisco CRS. The Cisco CRS (Carrier Routing System) is a core router platform with high-density interfaces and large scale for MPLS and Segment Routing.

Answer

Cisco ASR 9000

Answer

Cisco ISR 4000

Answer

Cisco NCS 5500

Question 9

A service provider wants to offer a point-to-point Ethernet service between two customer sites with a defined bandwidth and performance guarantee, according to MEF standards. Which Carrier Ethernet service type is appropriate?

Accepted Answer

E-Line. E-Line (Ethernet Line) is a point-to-point service defined by MEF for Carrier Ethernet.

Answer

E-LAN

Answer

E-Access

Answer

E-Tree

Question 10

In the context of network slicing for 5G, which type of slice is optimized for massive IoT with low data rates and high connection density?

Accepted Answer

mMTC. Massive IoT corresponds to mMTC (massive Machine Type Communications) slice, designed for many devices with low data rates.

Answer

uRLLC

Answer

V2X

Answer

eMBB

Question 11

An SP deploys EVPN to provide L2VPN services with multi-homing. The customer CE is dual-homed to two different PE routers. Which EVPN mechanism ensures that only one PE forwards traffic to the CE for a given Ethernet segment, preventing loops?

Accepted Answer

Designated Forwarder election based on ESI. Ethernet Segment Identifier (ESI) and designated forwarder (DF) election in EVPN ensure that only one PE forwards traffic to the CE for a given Ethernet segment, preventing loops.

Answer

BGP Route Reflector

Answer

MAC learning via data plane

Answer

Split horizon groups

Question 12

Which architecture feature of IOS XR ensures that a failure in one routing protocol process does not affect other processes on the same router?

Accepted Answer

Process separation with each protocol as a separate process. IOS XR uses a distributed OS with process separation; each protocol runs as a separate process in its own memory space, providing fault isolation.

Answer

Admin plane vs default SDR

Answer

Commit/rollback configuration model

Answer

CPU and memory allocation per card

Question 13

A service provider needs to offer L3VPN services with customer isolation. Which technology is used to maintain separate routing tables for different customers on a single PE router?

Accepted Answer

VRF. VRF (Virtual Routing and Forwarding) instances provide separate routing tables per customer, ensuring isolation in L3VPN.

Answer

VLAN

Answer

Route distinguisher (RD)

Answer

MPLS labels

Question 14

An SP uses Cisco NSO for automation. Which protocol does NSO typically use to push configuration changes to network devices?

Accepted Answer

NETCONF. NSO uses NETCONF as the primary protocol to push configuration changes, leveraging YANG data models.

Answer

RESTCONF

Answer

SNMP

Answer

CLI via SSH

Question 15

What is the primary function of the aggregation layer in a service provider network?

Accepted Answer

Aggregate traffic from the access layer and forward to the core. The aggregation layer collects traffic from access nodes and forwards it to the core, often performing QoS, filtering, and subscriber management.

Answer

Provide direct customer connections

Answer

Perform deep packet inspection

Answer

Provide high-speed backbone connectivity