View Full Cisco CCNP Service Provider 350-501 Exam Dumps and Practice Test Dumps.

 

Question 141

Which protocol is used to synchronize the clocks of network devices with a centralized time source?

1. NTP
2. BFD
3. LDP
4. PIM

Correct Answer: 1

Explanation

Network Time Protocol (NTP) is used to synchronize clocks across network devices and servers. Accurate time is important in service provider networks because logs, troubleshooting events, authentication systems, certificates, and monitoring systems often depend on consistent timestamps. NTP uses a hierarchy of time sources called strata, allowing devices to synchronize with reliable upstream clocks. BFD provides fast failure detection, LDP distributes MPLS labels, and PIM handles multicast routing. Therefore, NTP is the correct protocol for network time synchronization.

Question 142

Which protocol is commonly used to collect management information from network devices using a manager-agent architecture?

1. NETCONF
2. SNMP
3. BGP
4. RSVP

Correct Answer: 2

Explanation

Simple Network Management Protocol (SNMP) uses a manager-agent architecture for monitoring and managing network devices. An SNMP manager can query devices for operational information such as interface counters, CPU utilization, memory usage, and other MIB-defined objects. Network devices typically run an SNMP agent that responds to queries and may generate notifications such as traps. NETCONF is designed for structured configuration management, while BGP exchanges routing information and RSVP provides signaling capabilities. Therefore, SNMP is the correct protocol for traditional manager-agent network monitoring.

Question 143

Which SNMP operation allows a management system to retrieve the value of a specific object from a network device?

1. SET
2. TRAP
3. GET
4. INFORM

Correct Answer: 3

Explanation

The SNMP GET operation allows a management system to request the current value of a specific managed object from an SNMP agent. For example, a network management system can use GET operations to retrieve interface counters or device information. SET is used to modify supported management objects, while TRAP is an unsolicited notification sent by an agent to a management system. INFORM is also a notification mechanism but provides acknowledgment capabilities. Therefore, GET is the correct SNMP operation for retrieving a specific object value.

Question 144

Which technology provides structured, model-driven configuration and operational data access over a network management protocol?

1. NETCONF
2. TFTP
3. ARP
4. ICMP

Correct Answer: 1

Explanation

NETCONF is a network management protocol designed for structured configuration and operational data exchange. It commonly uses YANG data models to provide a standardized representation of network configuration and state. NETCONF can support transactional configuration operations, making it useful for automation and consistent device management. TFTP is a basic file-transfer protocol, ARP resolves IPv4 addresses to MAC addresses, and ICMP provides control and diagnostic messaging. Therefore, NETCONF is the appropriate technology for model-driven network configuration and management.

Question 145

Which data modeling language is commonly used with NETCONF and RESTCONF?

1. JSON
2. XML
3. YANG
4. YAML

Correct Answer: 3

Explanation

YANG is a data modeling language used to describe configuration data, operational state, notifications, and relationships between network elements. It is commonly associated with NETCONF and RESTCONF-based network management. YANG models define structured schemas that automation systems can use to understand and manipulate device configuration consistently. XML and JSON are data encoding formats rather than the primary modeling language, although NETCONF commonly uses XML and RESTCONF can use JSON or XML representations. YAML is also a data serialization format. Therefore, YANG is the correct answer.

Question 146

Which protocol provides HTTP-based access to YANG-modeled network configuration and operational data?

1. RESTCONF
2. LDP
3. PIM
4. BFD

Correct Answer: 1

Explanation

RESTCONF provides HTTP-based access to configuration and operational data modeled with YANG. It enables network automation applications to interact with network devices using familiar REST-style operations such as GET, POST, PUT, PATCH, and DELETE, depending on the resource and implementation. RESTCONF commonly uses JSON or XML for data representation. LDP distributes MPLS labels, PIM provides multicast routing, and BFD detects failures rapidly. Therefore, RESTCONF is the correct protocol for HTTP-based interaction with YANG-modeled network data.

Question 147

Which network automation principle means that applying the same configuration operation repeatedly should produce the same desired state?

1. Redundancy
2. Idempotency
3. Fragmentation
4. Encapsulation

Correct Answer: 2

Explanation

Idempotency is an important principle in network automation. An idempotent operation can be applied repeatedly without causing unintended additional changes after the desired state has already been achieved. For example, an automation system should be able to ensure that a particular interface configuration exists without repeatedly creating duplicate configuration statements. This makes automation safer and more predictable. Redundancy relates to availability, fragmentation divides data into smaller pieces, and encapsulation involves wrapping data with protocol information. Therefore, idempotency is the correct concept.

Question 148

Which telemetry approach continuously streams operational data from network devices to a monitoring or analytics system?

1. SNMP polling
2. Streaming telemetry
3. TFTP
4. ARP

Correct Answer: 2

Explanation

Streaming telemetry continuously sends selected operational data from network devices toward a collector or analytics platform. Unlike traditional polling, where a management system repeatedly asks devices for information, streaming telemetry allows devices to push updates as data changes or at configured intervals. This can provide more timely visibility into interface statistics, routing state, resource utilization, and other operational metrics. SNMP polling is traditionally request-driven, TFTP is a file-transfer protocol, and ARP resolves IPv4 addresses. Therefore, streaming telemetry is the correct approach for continuous operational data delivery.

Question 149

Which protocol is commonly used to exchange routing information between autonomous systems?

1. OSPF
2. IS-IS
3. BGP
4. EIGRP

Correct Answer: 3

Explanation

Border Gateway Protocol (BGP) is the primary routing protocol used to exchange routing information between autonomous systems. It is an exterior gateway protocol designed for large-scale interdomain routing and supports extensive policy control through attributes and routing policies. OSPF and IS-IS are primarily interior gateway protocols used within an autonomous system, while EIGRP is also an interior routing protocol. Service provider networks commonly use eBGP to exchange routes with external autonomous systems and iBGP to distribute BGP routes internally. Therefore, BGP is the correct answer.

Question 150

Which BGP attribute identifies the next-hop IP address that should be used to reach a BGP route?

1. NEXT_HOP
2. MED
3. ORIGIN
4. COMMUNITY

Correct Answer: 1

Explanation

The BGP NEXT_HOP attribute identifies the IP address that should be used as the next hop when forwarding traffic toward a BGP-learned destination. The next-hop value can behave differently depending on whether the route is learned through eBGP or iBGP and on the configured policies. For example, next-hop-self is often configured on internal BGP speakers when an appropriate internal next hop needs to be advertised. MED influences path selection between neighboring autonomous systems, ORIGIN indicates route origin type, and COMMUNITY carries policy information. Therefore, NEXT_HOP is correct.

Question 151

Which BGP feature can preserve established forwarding information during a control-plane restart to reduce traffic disruption?

1. Route Reflector
2. Graceful Restart
3. Add-Path
4. Route Dampening

Correct Answer: 2

Explanation

BGP Graceful Restart allows forwarding to continue using existing routing information while a control-plane component restarts, provided the necessary capabilities are supported by the participating devices. During the restart, neighboring routers can retain relevant routes for a defined period while the restarting router reestablishes BGP sessions. This can reduce packet loss during certain control-plane events. Route Reflectors improve iBGP scalability, Add-Path advertises multiple paths, and Route Dampening addresses route instability. Therefore, Graceful Restart is the correct feature for reducing disruption during supported control-plane restarts.

Question 152

Which BGP feature is designed to limit the number of prefixes accepted from a particular BGP neighbor?

1. Maximum Prefix
2. Route Refresh
3. Local Preference
4. Add-Path

Correct Answer: 1

Explanation

The BGP Maximum Prefix feature allows an administrator to limit the number of prefixes accepted from a BGP neighbor. This provides an important operational and security safeguard because an unexpected routing table increase from a peer can consume memory and processing resources. When the configured threshold is reached, the router can take a configured action, such as generating warnings or shutting down the session. Route Refresh handles route re-advertisement, Local Preference influences path selection, and Add-Path allows multiple paths to be advertised. Therefore, Maximum Prefix is correct.

Question 153

Which BGP mechanism allows a router to retain multiple valid paths internally so that a backup path can be used rapidly after a failure?

1. BGP PIC
2. SNMP
3. IGMP
4. DHCP

Correct Answer: 1

Explanation

BGP Prefix-Independent Convergence (BGP PIC) improves convergence by allowing backup paths to be prepared in advance so forwarding can switch rapidly when the primary path fails. Instead of requiring extensive per-prefix recalculation before traffic can use an alternate path, the forwarding infrastructure can update relevant next-hop information more efficiently. This is particularly valuable in large service provider networks where many prefixes may be affected by a single failure. SNMP is used for management, IGMP handles multicast membership, and DHCP provides address configuration. Therefore, BGP PIC is correct.

Question 154

Which MPLS service provides a point-to-point Layer 2 Ethernet connection between two customer sites?

1. VPLS
2. VPWS
3. L3VPN
4. Internet VPN

Correct Answer: 2

Explanation

Virtual Private Wire Service (VPWS) provides point-to-point Layer 2 connectivity across a provider network. It can transport customer Ethernet frames between two endpoints using a pseudowire through the MPLS infrastructure. The provider network presents a logical point-to-point service while hiding its internal topology from the customer. VPLS is designed for multipoint Layer 2 connectivity, while L3VPN provides routed Layer 3 VPN services. Therefore, VPWS is the correct service when a customer requires a point-to-point Layer 2 connection.

Question 155

Which Layer 2 VPN technology provides multipoint Ethernet connectivity over an MPLS network?

1. VPWS
2. VPLS
3. BFD
4. LDP

Correct Answer: 2

Explanation

Virtual Private LAN Service (VPLS) provides multipoint Layer 2 connectivity across an MPLS network. It allows multiple customer sites to participate in a virtual Ethernet service as if they were connected to the same logical LAN. Provider-edge devices maintain the necessary Layer 2 forwarding information and use pseudowires to transport frames across the provider network. VPWS is generally point-to-point, while BFD provides failure detection and LDP distributes MPLS labels. Therefore, VPLS is the correct technology for multipoint Ethernet VPN connectivity.

Question 156

Which Ethernet service feature allows customer VLAN tags to be encapsulated inside an additional provider VLAN tag?

1. QinQ
2. LACP
3. STP
4. LLDP

Correct Answer: 1

Explanation

QinQ, also known as VLAN stacking or 802.1ad, allows an additional VLAN tag to be added to an Ethernet frame that already contains a customer VLAN tag. The outer provider tag can identify a customer or service while preserving the customer’s original VLAN information inside the frame. This is useful for service providers transporting multiple customer VLANs across a shared infrastructure. LACP provides link aggregation, STP prevents Layer 2 loops, and LLDP exchanges device and link information. Therefore, QinQ is the correct technology.

Question 157

Which protocol is commonly used to dynamically negotiate Ethernet link aggregation between neighboring devices?

1. LLDP
2. LACP
3. STP
4. CDP

Correct Answer: 2

Explanation

Link Aggregation Control Protocol (LACP) dynamically negotiates and maintains link aggregation between compatible Ethernet devices. Multiple physical interfaces can be combined into a logical port-channel, providing additional bandwidth and redundancy. LACP can detect changes in member links and adjust the aggregation accordingly. LLDP is used to exchange neighbor information, STP prevents Layer 2 loops, and CDP is a Cisco neighbor-discovery protocol. Therefore, LACP is the correct protocol for dynamically establishing and maintaining Ethernet link aggregation.

Question 158

Which Ethernet discovery protocol allows devices to advertise information such as system name and interface details to directly connected neighbors?

1. LDP
2. LLDP
3. BFD
4. PIM

Correct Answer: 2

Explanation

Link Layer Discovery Protocol (LLDP) is a standards-based Layer 2 discovery protocol that allows network devices to advertise information to directly connected neighbors. Advertised information can include system identity, port information, capabilities, and management addresses. This information is useful for network documentation, troubleshooting, topology discovery, and management systems. LDP is associated with MPLS label distribution, BFD provides rapid failure detection, and PIM handles multicast routing. Therefore, LLDP is the correct protocol for exchanging neighbor information at Layer 2.

Question 159

Which protocol is designed to detect forwarding-path failures independently of a routing protocol?

1. BFD
2. OSPF
3. BGP
4. IS-IS

Correct Answer: 1

Explanation

Bidirectional Forwarding Detection (BFD) provides rapid detection of forwarding-path failures between neighboring devices. It operates independently of the specific routing protocol and can be integrated with protocols such as OSPF, IS-IS, BGP, and MPLS-related mechanisms. BFD is designed for fast failure detection, allowing associated routing or forwarding processes to react more quickly than they might through standard protocol timers alone. OSPF, BGP, and IS-IS are routing protocols with broader responsibilities. Therefore, BFD is the correct technology for rapid forwarding-path failure detection.

Question 160

Which MPLS traffic-engineering technology can establish an explicitly signaled path using RSVP?

1. LDP
2. RSVP-TE
3. IGMP
4. SNMP

Correct Answer: 2

Explanation

RSVP-TE, or Resource Reservation Protocol-Traffic Engineering, can establish explicitly signaled MPLS traffic-engineered paths through a network. It can use explicit path information and reserve resources according to configured requirements. This allows traffic to follow a path that differs from the shortest IGP path when necessary for traffic engineering, bandwidth management, or protection objectives. LDP generally follows IGP-derived paths, while IGMP manages multicast membership and SNMP provides network management. Therefore, RSVP-TE is the correct technology for establishing explicitly signaled MPLS traffic-engineered paths.