350-501 · domain
Architecture
Practise Cisco SPCOR / CCNP Service Provider Core 350-501 Architecture practice questions — original exam-style scenarios with answer choices, explanations, and analysis of common mistakes.
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Architecture questions test whether you can apply the concept in context, not just recognise a definition.
How the topic appears in realistic exam-style scenarios.
Which detail in the question changes the correct answer.
How to eliminate plausible but wrong options.
How to connect the question back to the wider exam objective.
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Common Architecture exam traps
- ▸Answering from memory before reading the full scenario.
- ▸Missing a constraint such as cost, availability, security, scope or command context.
- ▸Choosing a broad answer when the question asks for the most specific fix.
- ▸Ignoring why the wrong options are tempting.
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All Architecture questions (232)
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A service provider is deploying Segment Routing (SR) with TI-LFA for fast convergence. Which mechanism does TI-LFA use to repair a link failure in a node segment path?
Hard2A service provider is implementing MPLS-TE with FRR (Fast Reroute) using one-to-one backup tunnels. After activation, they notice that the number of labels in the forwarding table has increased significantly. What is the most likely reason for this increase?
Hard3Refer to the exhibit. A PE router is showing a VRF route. What does the [200/0] indicate?
Medium4A service provider wants to offer Layer 2 VPN services using MPLS. Which technology should be used to transport Ethernet frames across the MPLS core?
Easy5A service provider is deploying multicast over MPLS L3VPN. Which mechanism is used to provide multicast in the core between PE routers?
Hard6A service provider is redesigning its MPLS core to support both L3VPN and L2VPN services. They want to minimize the number of labels in the forwarding table while maintaining per-VRF label allocation. Which label allocation mode should be used for the L3VPN service?
Medium7Which TWO statements accurately describe the differences between GPON and XGS-PON? (Choose two.)
Medium8Which MEF service type provides a point-to-point Ethernet connection between two user-network interfaces (UNIs)?
Medium9Which technology provides Layer 2 multipoint connectivity over an MPLS network, where customer sites appear to be on the same Ethernet broadcast domain?
Medium10A service provider is deploying an MPLS L3VPN solution for a customer with two sites. The PE routers are running OSPF as the IGP and LDP for label distribution. The provider wants to ensure that customer traffic is load-balanced across two equal-cost paths between the PEs. The network team notices that all traffic is taking only one path despite the IGP showing equal-cost routes. The team has verified that the MPLS forwarding table on the P router shows only one label entry for the BGP next-hop. The team suspects a load-balancing issue. Which action best resolves the problem?
Hard11An SP is deploying MPLS in the core/backbone to support L3VPN services. What is the purpose of MP-BGP in an MPLS VPN architecture?
Medium12A provider is implementing EVPN for data center interconnect. They require multi-homing with all-active load balancing and fast convergence using BGP. Which EVPN feature enables this?
Medium13An 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?
Hard14A large SP network uses Segment Routing (SR) with MPLS data plane. They want to enforce a strict path for certain traffic flows across the core while using shortest-path for others. Which technique should be used?
Hard15Which two protocols are commonly used for label exchange in an MPLS network? (Choose two.)
Easy16A service provider is troubleshooting a BGP route advertisement issue. Routes from a customer are not being advertised to the upstream provider. The PE router is configured with 'neighbor 10.0.0.1 route-map RMAP out'. The route-map RMAP permits the customer prefix. However, the BGP table on the PE shows the prefix as valid but not advertised. What is a likely cause?
Medium17A service provider is implementing Segment Routing (SR) with MPLS. Which three statements are true regarding SR-MPLS? (Choose three.)
Hard18A service provider is deploying EVPN-VPWS for point-to-point services. They have set up an EVPN instance with Ethernet Segment Identifier (ESI) and EVI. After configuration, the pseudowire is not coming up. Which misconfiguration is most likely?
Medium19A service provider has deployed QoS on its MPLS backbone to offer different classes of service. The provider notices that EF (Expedited Forwarding) traffic sometimes experiences high jitter during congestion. Following recommended practices, which action is MOST likely to reduce jitter for EF traffic?
Medium20Which statement about the commit/rollback configuration model in IOS XR is true?
Medium21An ISP is deploying EVPN-VXLAN for its data center interconnect. Which statement about control-plane learning is correct?
Hard22You are a network architect for a large service provider. The network consists of multiple core routers (P routers) and edge routers (PE routers) supporting both L3VPN and L2VPN services. The network currently uses LDP for label distribution and has a flat IGP (OSPF) design. Recently, there have been scalability issues: the IGP convergence time has increased significantly, and the OSPF link-state database (LSDB) has grown large, causing high CPU utilization on core routers. Additionally, the LDP sessions are taking longer to establish after a router reboot. You are tasked with redesigning the network to improve scalability and convergence. The budget allows for significant changes but cannot replace all hardware. Which approach best addresses the scalability issues while minimizing disruption?
Hard23Refer to the exhibit. The router is configured as a PE router in an MPLS VPN network. Which option correctly identifies a configuration error that would prevent proper operation?
Medium24A service provider is designing an MPLS L3VPN network to provide Layer 3 VPN services to multiple customers. Which two statements correctly describe the roles of the Provider Edge (PE) and Customer Edge (CE) routers in this architecture?
Medium25Which access technology is based on ITU-T G.984 and provides downstream speeds up to 2.488 Gbps?
Easy26An SP is deploying a Quality of Service (QoS) architecture in its core network to support multiple services: voice, video, and data. The core routers use MPLS and implement QoS based on the MPLS EXP bits. The architecture must ensure that voice packets are never dropped, even during congestion, while allowing video to have higher priority than data. The current design marks voice with EXP 4, video with EXP 3, and data with EXP 0. During a traffic burst, voice traffic is being dropped, which should not happen. The core routers have the following queue configuration: (1) a priority queue (PQ) for EXP 4+5, (2) a bandwidth queue for EXP 2-3, (3) a default queue for EXP 0-1. What is most likely the cause of voice drops?
Easy27Which THREE are requirements for deploying MPLS Traffic Engineering with RSVP-TE?
Hard28In an IOS XR system, CPU and memory resources are allocated per line card. What is the primary reason for this design?
Medium29A service provider is deploying network slicing for 5G services. Which slice type is characterized by low latency and high reliability for applications like autonomous driving?
Hard30Refer to the exhibit. A PE router configuration for VRF CUST1 is shown. What is the most likely result when a CE sends a route with RT 100:100?
Easy31Which 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?
Easy32Which Cisco automation tool is designed for service modeling with YANG and provides lifecycle management of network services?
Easy33A service provider is implementing MPLS L3VPN for a customer. The customer requires that routes from two different VPNs be imported into a single VRF. Which feature should be used?
Easy34Which THREE protocols are used for label distribution in an MPLS network?
Easy35A service provider offers Carrier Ethernet services using MPLS-TP in the access and aggregation layers. The network uses MPLS-TP tunnels with static LSPs and protection via 1:1 linear protection with APS. One customer reports intermittent connectivity issues on their E-LINE service. The operations team observes that the protection switchover is occurring frequently due to apparent signal failures on the working path. However, the physical layer shows no errors. The protection switching is configured with revertive mode. The working LSP has an RDI (Remote Defect Indication) configured. Upon further investigation, the team finds that the working LSP's OAM continuity check messages (CCMs) are being lost occasionally, triggering a protection switch. What is the most likely misconfiguration?
Medium36Which Cisco platform is designed for high-capacity core/backbone routing with support for MPLS, Segment Routing, and large-scale BGP?
Easy37A service provider wants to implement Segment Routing in its MPLS core to simplify traffic engineering. What is the primary advantage of Segment Routing over traditional RSVP-TE?
Medium38In a carrier's network, MPLS-TE tunnels are used to steer traffic away from congested links. The operator configures a tunnel with a bandwidth of 200 Mbps and a dynamic path. The CSPF computation shows a path with sufficient bandwidth, but the tunnel fails to come up. The RSVP neighbor is established. What is the most likely cause?
Hard39A service provider is using NSO for service orchestration. Which protocol does NSO use to communicate with network devices for configuration?
Hard40Refer to the exhibit. An engineer has configured an SR-TE policy. What is required for this policy to be used for traffic steering?
Hard41A service provider is deploying EVPN-VXLAN in its data center to provide Layer 2 and Layer 3 overlay services. The underlay uses an eBGP-based CLOS fabric with spine and leaf switches. The leaf switches act as VTEPs and run EVPN for MAC/VXLAN advertisement. One of the tenants, a financial customer, requires that their traffic between two leaf-connected servers is always forwarded through a firewall for inspection, even when the servers are on the same leaf. The firewall is connected to a service leaf. The architect proposes using EVPN integrated routing and bridging (IRB) with asymmetric IRB. However, traffic between two VMs on the same leaf is bypassing the firewall. Which architectural change ensures that all inter-VM traffic within the same leaf goes through the firewall?
Medium42In IOS XR architecture, what is the role of the Secure Domain Router (SDR)?
Easy43In EVPN, what is the function of the Ethernet Segment Identifier (ESI)?
Medium44An SP is deploying network slicing for 5G services. They need to ensure ultra-reliable low-latency communication (uRLLC) slice has dedicated bandwidth and low latency. Which mechanism is best suited to guarantee performance for this slice?
Hard45A service provider uses BGP communities to influence routing policies. An administrator wants to prevent a specific prefix from being advertised to any external AS. Which BGP community should be applied?
Hard46A 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?
Medium47Which MEF Carrier Ethernet service type is used for a rooted-multipoint topology, where a single root site communicates with multiple leaf sites but leaf sites cannot communicate directly?
Medium48You are a network engineer at a service provider that offers L3VPN services. A customer complains that their VPN traffic is intermittently dropping. The network uses OSPF as the IGP, LDP for label distribution, and MP-BGP for VPNv4 route exchange. The PE routers are connected to two core routers (P1 and P2) in a redundant design. Upon investigation, you find that the BGP next-hop for some VPN prefixes is set to the loopback interface of the remote PE, but the route to that loopback is sometimes unreachable due to a flapping link between P1 and P2. The IGP converges, but the BGP prefixes take longer to recover. What is the most likely cause of the intermittent drops?
Medium49A service provider is designing a new MPLS core network and needs to choose a routing protocol that supports traffic engineering and fast convergence. Which protocol should be used?
Easy50A network engineer is designing a Layer 2 VPN using EVPN with MPLS data plane. The customer requires all-hub multipoint connectivity with optimal multicast replication. Which EVPN route type is used to advertise multicast group membership?
Hard51A service provider is deploying a new MPLS core network and needs a router platform that supports high-scale MPLS forwarding and offers a modular operating system. Which Cisco platform is best suited for this role?
Medium52In IOS XR, what is the primary purpose of the commit/rollback configuration model?
Medium53What is the main benefit of using Q-in-Q (802.1ad) in metro Ethernet networks?
Easy54Which network architecture model separates the control plane and data plane in a way that allows for centralized control and distributed forwarding?
Easy55In an MPLS-based service provider core network, the aggregation layer typically connects to the core backbone. Which technology is primarily used at the aggregation layer to scale Ethernet services for many customers while preserving VLAN separation?
Medium56Which THREE of the following are required components for implementing MPLS Layer 3 VPN (L3VPN) in a service provider network? (Choose three.)
Medium57Which TWO are correct about network slicing? (Choose two.)
Hard58Which TWO statements about IOS XR architecture are correct? (Choose two.)
Medium59An SP is using Cisco ASR 9000 routers with IOS XR. They need to apply a configuration change and ensure that if the change causes issues, it can be easily reverted. Which IOS XR feature supports this?
Medium60Which Cisco platform is best suited for the core/backbone role of a large service provider network, offering high scalability and MPLS forwarding capacity?
Medium61Which Cisco SP router platform runs IOS XR and is designed for the aggregation layer with high-density 10GE/100GE interfaces?
Easy62Which TWO access technologies are considered fiber-based solutions for service provider access networks? (Select two.)
Easy63A multicast service provider is designing an IPv4 PIM Sparse Mode (PIM-SM) network with multiple RPs. The network must support Anycast RP using MSDP. Which THREE statements are correct regarding this design?
Hard64A service provider wants to provide point-to-point Ethernet services with strict SLAs. Which technology should they use?
Hard65A network engineer is troubleshooting an OSPF issue in a service provider network. The network uses OSPFv2 with multiple areas. Routers in area 0 are able to ping each other, but routers in area 1 cannot reach routers in area 2. All routers are OSPF-enabled and have correct network type configurations. What is the most likely cause?
Easy66Refer to the exhibit. What is the significance of the entry with 'Pop Label'?
Hard67When configuring EVPN VPWS, which TWO parameters must match between the two endpoints of the pseudowire?
Hard68In a BGP/MPLS IP VPN, which technique ensures that customer traffic from different VPNs remains isolated on the same PE router?
Medium69A network architect is designing a Segment Routing (SR) network for a service provider with a requirement for fast convergence upon node failure. The network uses IS-IS as the IGP with segment routing extensions. Which design choice BEST ensures that the network can achieve sub-50ms convergence without relying on any signaling protocol beyond the IGP?
Hard70Which THREE of the following are benefits of using EVPN over traditional VPLS for L2VPN services? (Select three.)
Hard71A 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?
Easy72In an IS-IS segment routing network, after the global 'segment-routing mpls' configuration, which IS-IS configuration is mandatory for label allocation?
Medium73In EVPN, what is the purpose of Ethernet Segment Identifier (ESI)?
Medium74What is the purpose of the 'mpls ldp autoconfig' command on an interface?
Easy75What is the role of Network Services Orchestrator (NSO) in service provider automation?
Medium76In a carrier network using VRF-lite for customer isolation, which issue arises if route-target values are not correctly configured?
Medium77Which MPLS label is used to identify the egress PE in a Layer 3 MPLS VPN?
Easy78In a multicast environment, a PE router is not receiving multicast traffic from a source behind a CE. The PIM neighbors are established. The RP is reachable. What is the most likely issue?
Medium79A service provider wants to provide Layer 3 VPN services to customers using MPLS. Which technology is used to distribute VPNv4 routes between PE routers?
Easy80Which three are benefits of using MPLS Layer 3 VPNs over traditional VPNs? (Choose three.)
Hard81Based on the exhibit, which label operation will occur when a packet destined to 10.2.2.1 enters PE1 with label 17?
Easy82Which Cisco router platform is designed for the aggregation layer and supports both mobile backhaul and business services with high density 10GE/100GE interfaces?
Easy83A service provider is deploying Segment Routing in the MPLS core using IS-IS. Which extension is required in IS-IS to advertise the prefix-SID?
Easy84A large service provider operates a national MPLS backbone with over 200 P routers and 500 PE routers. They use IS-IS as the IGP with segment routing and have deployed TI-LFA for link and node protection. Recently, a core router (P1) suffered a complete failure, and during the failure, traffic for some prefixes was dropped for over 200ms. After the failure, the network recovered within seconds. The engineer suspects that TI-LFA did not provide the expected sub-50ms protection for some destinations. Further analysis reveals that the affected prefixes have their BGP next-hop on a router that is multiple hops away, and the P1 failure impacted both the primary path and the backup path computed by TI-LFA. The engineer reviews the TI-LFA configuration and finds that 'fast-reroute per-prefix ti-lfa' is enabled under router isis. The engineer also notes that P1 was not a protecting node for those prefixes. Which action should the engineer take to improve convergence time for these prefixes?
Hard85In a service provider network, the access layer connects end customers. Which technology is commonly used for fibre-based access in GPON deployments?
Easy86A service provider is implementing MPLS TE to optimize bandwidth utilization. The engineer notices that tunnels are not using the explicitly configured path. What is the most likely reason?
Medium87Which TWO are characteristics of the access layer in a service provider network? (Choose two.)
Easy88A service provider is deploying MPLS in its core network. The core routers are all configured with LDP. Which label operation does an ingress PE perform on the first packet of a new flow?
Easy89In IS-IS, which TWO are types of Link State PDUs (LSPs)?
Easy90In a carrier-supporting carrier (CSC) architecture, the customer carrier runs MPLS in its network. Which technology is used to exchange VPN routes between the provider carrier and the customer carrier?
Hard91A service provider is designing its core network to carry both IPv4 and IPv6 traffic. Which BGP approach best minimizes routing table size on core routers while maintaining full reachability?
Easy92Which THREE of the following are key components of an MPLS L3VPN architecture? (Choose three.)
Medium93In an MPLS core, which forwarding mechanism do P routers use to forward packets for L3VPN?
Medium94Refer to the exhibit. A network engineer configures a BGP route-map to set communities on routes advertised to a neighbor. After applying the configuration, the engineer checks the BGP table on the neighbor router and does not see the communities. What is the most likely reason?
Medium95A service provider offers L3VPN services to multiple enterprise customers. One customer reports that they cannot reach some remote sites intermittently. The network uses MPLS L3VPN with MP-BGP for VPN route exchange. The PE routers are configured with route-target import and export. The customer's CE router is dual-homed to two different PEs in the same point of presence. The engineer checks the BGP table on both PEs and sees the customer routes with the correct route-target. However, pings from the CE to a remote site fail about 50% of the time, and the flapping pattern suggests load balancing issues. The engineer discovers that the remote site's network prefix is being advertised from both PEs with the same route-target but with different next-hops. The CE has equal-cost paths via both PEs. What is the most likely cause of the intermittent connectivity?
Medium96An SP is migrating its core network to Segment Routing (SR-MPLS). The network uses IS-IS as the IGP with SR extensions. Which three statements about SR-MPLS architecture are correct?
Hard97A network operator is deploying segment routing in an MPLS network. They want to use a centralized controller to compute paths based on traffic demand and network constraints. Which architecture is being used?
Hard98In Inter-AS MPLS Option B, which routers exchange labeled VPNv4 prefixes directly?
Medium99When deploying IS-IS in a large service provider core, what is the recommended network type on Ethernet interfaces to improve scalability?
Easy100A service provider is implementing EVPN for its VPLS replacement. They have configured BGP EVPN on all PEs and have set up an EVPN instance for a customer requiring broadcast, unknown unicast, and multicast (BUM) traffic. The customer reports that broadcast traffic from one site is not being received at another site. The engineer checks the EVPN configuration and finds that the EVI is configured correctly, the route-target matches, and the BGP sessions are established. The engineer also checks the MAC address table on the receiving PE and sees that the source MAC of the broadcast frame is learned on the local interface, but not from the remote VTEP. The engineer suspects an issue with the IMET (Inclusive Multicast Ethernet Tag) route. Which action should the engineer take to verify the IMET route?
Medium101A service provider is troubleshooting an MPLS L3VPN where customers behind CE-A cannot reach CE-B. The PE routers are Cisco ASR 9000 series. On PE-A, the show cef vrf CUSTOMER prefix 10.1.1.0/24 command displays 'punt' as the forwarding path. What is the most likely cause?
Medium102Which THREE are correct statements about IOS XR process separation? (Choose three.)
Hard103Which Cisco SP router platform uses IOS XR and is commonly deployed at the aggregation layer, supporting both L2 and L3 services?
Medium104Match each MPLS protection mechanism to its description.
Medium105Refer to the exhibit. Which statement is true about this configuration?
Easy106A network engineer is troubleshooting QoS in a service provider environment. Customer traffic is marked with DSCP AF31 (011010) at the CE. On the PE router, the policy maps trust DSCP and sets the CoS to 4. However, core routers remark the DSCP to 0. What is the most likely cause?
Medium107A service provider wants to offer a point-to-point Layer 2 Ethernet service between two customer sites with strict SLAs. The solution must use MPLS pseudowires. Which MEF service type aligns with this requirement?
Hard108Which TWO are benefits of using Segment Routing over LDP in a service provider core?
Medium109Which Cisco automation tool uses service models in YANG and communicates via NETCONF to orchestrate device configurations and lifecycle management?
Easy110An SP is designing a GPON access network. Which technology allows multiple ONUs to share the same fiber using different wavelengths for upstream and downstream?
Hard111Based on the exhibit, why is the route 10.10.10.0/24 from remote PE not installed in the VRF Customer-A on PE1?
Hard112An engineer is designing an MPLS L3VPN solution and must ensure that the provider edge (PE) routers can handle routing updates for multiple customers without interfering with each other. Which mechanism should be used on the PE routers?
Medium113In a Cisco IOS XR router, which statement best describes process separation?
Hard114In BGP/MPLS IP VPN (L3VPN), which component provides customer isolation by maintaining separate routing tables per customer?
Medium115A service provider is deploying Segment Routing over IPv6 (SRv6) and needs to ensure that the forwarding plane can support SRv6 encapsulated packets. Which hardware capability is most critical for SRv6 at the line rate?
Hard116A service provider is implementing EVPN to support multi-homing for a customer site. Which EVPN attribute ensures that only one of the PEs forwards traffic for a given Ethernet segment?
Medium117A service provider operates an MPLS-TE network using RSVP-TE with a full mesh of tunnels between core routers. The network uses OSPF as IGP with traffic engineering extensions. Recently, a new headend router PE-New was added and configured with several TE tunnels to remote destinations. However, some tunnels repeatedly go down after a few minutes and show in the 'down' state with the error 'Tunnel path option 0: no path to destination (TEDB lookup failed)'. The TE tunnels that remain up are those to destinations that are directly connected to the same OSPF area. The network has multiple OSPF areas (area 0, 1, 2) with inter-area routes redistributed. The operator suspects the issue is related to the TEDB (Traffic Engineering Database) not having complete information. Which action is MOST likely to resolve the issue?
Easy118Drag and drop the steps to configure EIGRP on a Cisco router into the correct order.
Medium119An SP is deploying EVPN to provide both L2 and L3 VPN services. Which advantage does EVPN offer over traditional VPLS for multi-homing?
Hard120A service provider is designing a core network with IS-IS as the IGP. To support MPLS traffic engineering, which IS-IS extensions are required?
Medium121Which TWO statements about EVPN Route Type 2 (MAC/IP advertisement) are correct?
Medium122In the context of EVPN, which BGP address family is used to advertise MAC/VPN routes between PE routers?
Hard123Refer to the exhibit. The router is configured as a route reflector for VPNv4. What is the requirement for the route reflector to propagate VPNv4 routes received from a client to other clients?
Hard124Which protocol is used to exchange label binding information in a classic MPLS network without Segment Routing?
Medium125In IOS XR, each routing protocol runs as a separate process. What is the primary benefit of this architecture?
Medium126A service provider is designing a BGP-based network. Which TWO are characteristics of BGP within a service provider core?
Medium127Which encapsulation technology is commonly used in service provider networks to separate subscriber traffic in an Ethernet aggregation network?
Easy128Which architecture feature of IOS XR ensures that a failure in one routing protocol process does not affect other processes on the same router?
Medium129Which THREE of the following are key characteristics of Cisco IOS XR operating system?
Hard130In Cisco IOS XR architecture, using Secure Domain Routers (SDRs) allows partitioning a physical router into multiple logical routers. Which statement about admin plane and SDRs is correct?
Hard131Which two are requirements for deploying Segment Routing in a service provider network? (Choose two.)
Medium132Which Cisco router platform is designed for the aggregation layer and runs IOS XR, supporting both L2 and L3 services at high density?
Easy133An SP is deploying Inter-AS MPLS VPN option B. Which design characteristic is unique to Option B compared to Option A?
Medium134A network engineer is designing a new MPLS core. Which three of the following are recommended best practices for MPLS LDP configuration? (Choose three.)
Easy135In a Carrier Supporting Carrier (CSC) architecture, which condition is necessary for the customer carrier's BGP routes to be carried over the provider carrier's MPLS backbone?
Hard136A service provider is deploying EVPN-MPLS for L2VPN services. The customer requires that MAC addresses learned from one PE are not advertised to other PEs unless they are active. Which EVPN route type is used for MAC address withdrawal?
Medium137A service provider is troubleshooting an L2VPN where a CE is unable to ping the remote CE. The PE-CE interfaces are up, and the pseudowire status shows 'up'. Which two actions should be taken to further isolate the issue? (Choose two.)
Medium138In Segment Routing, what is the role of the 'Prefix-SID'?
Medium139A service provider is implementing network slicing for 5G services. Which of the following is NOT a typical characteristic of a network slice?
Hard140A customer reports that CE routers attached to PE1 and PE2 in the same VRF cannot ping each other. Based on the exhibit, what is the most likely cause?
Medium141A service provider is designing a Layer 3 MPLS VPN for a customer with two sites. The customer requires fast convergence in case of a PE-CE link failure. Which routing protocol should be used between PE and CE to achieve the fastest convergence?
Easy142Which TWO statements about MPLS label operations in a service provider core are correct? (Choose two.)
Hard143Which Cisco router platform is designed for high-density 100GE and uses IOS XR, making it suitable for the core/backbone of a service provider network?
Medium144A service provider is deploying L3VPN using BGP/MPLS. Which mechanism ensures customer isolation in the provider network?
Medium145In IOS XR, which process is responsible for managing the configuration database and commit operations?
Medium146Which MEF service type defines a point-to-point Ethernet connection, often used for business connectivity?
Medium147An SP is migrating from an MPLS LDP-based network to Segment Routing. They want to ensure that existing LDP LSPs continue to work alongside SR LSPs during the migration. Which mechanism should be configured?
Hard148A service provider is experiencing suboptimal routing due to BGP route reflection. To improve path selection while maintaining IBGP scalability, which feature should be implemented?
Medium149An engineer is configuring LDP in an MPLS network. Which THREE are valid label distribution modes for LDP?
Hard150A service provider is deploying L3VPN. Which mechanism ensures that customer routes are isolated and not leaked between different customers?
Medium151Which 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?
Medium152In the context of IOS XR commit/rollback configuration model, which command is used to apply a set of configuration changes as a single atomic operation?
Medium153In IOS XR, each routing protocol runs as a separate process. What is the primary benefit of this architecture?
Medium154Which TWO of the following are characteristics of the IOS XR operating system architecture? (Select two.)
Medium155A large ISP is designing a multicast architecture to support IPTV, requiring high availability and minimal traffic convergence. Which RP placement design is most appropriate?
Hard156A service provider is implementing EVPN with MPLS data plane. Which encapsulation type is used in MPLS EVPN to carry Ethernet frames across the MPLS network?
Hard157Which TWO are functions of the MPLS data plane?
Easy158Which THREE are benefits of implementing MPLS-TE in a service provider core?
Medium159A service provider needs to offer L3VPN services to multiple customers, each with overlapping IP addresses. The provider plans to use MPLS VPNs with VRFs. Which statement is TRUE regarding the configuration of VRFs on the PE routers?
Easy160Match each MPLS VPN technology to its description.
Medium161Which access technology uses a passive optical splitter to deliver broadband services to multiple subscribers over a single fiber?
Easy162Which TWO of the following are advantages of segment routing over traditional LDP-based MPLS? (Choose two.)
Medium163Which MPLS-based service provides point-to-point Ethernet connectivity over a service provider network, emulating a wire?
Easy164A customer is experiencing intermittent packet loss in an MPLS L3VPN network. The PE routers show no errors on interfaces. Which tool can help isolate the issue by showing the complete path a packet takes through the MPLS network?
Medium165A service provider is deploying Segment Routing Traffic Engineering (SR-TE) with a Path Computation Element (PCE). The PCE fails to compute a path for an SR-TE policy configured with constraint 'avoid nodes in affinity red'. The core network has red affinity assigned to several nodes. Which is the most likely cause?
Hard166An SP has configured MPLS TE tunnels for traffic engineering. To verify the status of the TE tunnels, which command provides the most relevant information?
Easy167Which TWO are key features of IOS XR architecture? (Choose two.)
Medium168In Segment Routing over IPv6 (SRv6), what is the function of the SRH (Segment Routing Header)?
Hard169Which Cisco platform is designed for the core/backbone of large service provider networks and offers high scalability with IOS XR?
Hard170In IOS XR architecture, what is the purpose of Secure Domain Router (SDR)?
Easy171Which MEF service type provides a multipoint-to-multipoint Ethernet virtual connection?
Easy172What is the primary function of the aggregation layer in a service provider network?
Easy173An SP is managing a large MPLS network and needs to verify the MPLS forwarding entries for a specific VRF. Which command provides the most complete information for the VRF?
Easy174Which component of the IOS XR architecture is responsible for managing the system configuration and providing a separation of control plane for multiple tenants?
Easy175Which TWO are essential components for deploying EVPN in a service provider network?
Hard176Which MPLS-based service provides point-to-point Ethernet connectivity over a service provider network, also known as a pseudowire?
Easy177An SP is using NETCONF with YANG to automate VRF provisioning. The engineer notices that the NETCONF session is established but configuration changes are not applied. Which issue is most likely?
Hard178A service provider wants to provide a point-to-point Ethernet service between two customer sites with strict Service Level Agreements (SLAs). Which MEF service type should be used?
Medium179Which TWO of the following are characteristics of MPLS L3VPN architecture? (Choose two.)
Medium180An engineer is configuring QoS on a service provider edge router to prioritize real-time traffic. Which queuing mechanism provides the lowest latency and jitter for voice traffic?
Easy181A service provider is troubleshooting BGP route selection for prefixes received from two different peers. The first peer prepends its AS path twice, making it longer than the second peer's path. However, the router still prefers the route with the longer AS path. Which additional attribute could cause this behavior?
Medium182A service provider wants to automate service provisioning using NSO. Which protocol is typically used by NSO to configure network devices?
Medium183Which TWO are benefits of using EVPN over traditional VPLS for L2VPN services? (Choose two.)
Medium184Which THREE are MEF-defined Ethernet service types? (Choose three.)
Hard185An SP network uses NTP for synchronization. To secure NTP, which authentication mode should be used?
Easy186In an MPLS VPN environment, which address family is used to exchange VPNv4 routes between PE routers?
Easy187What is the function of the admin plane in IOS XR architecture?
Medium188A service provider is designing a network to support mobile backhaul for eMBB, uRLLC, and mMTC services. Which technology allows the physical network to be divided into virtual networks with dedicated resources for each service type?
Hard189Which THREE are benefits of using EVPN over traditional VPLS? (Choose three.)
Hard190A service provider is building a new network slicing architecture to offer differentiated services to enterprise customers. The architecture uses SRv6 with network slices identified by slice IDs embedded in the SRv6 SID. The underlay is an IP network with ISIS. Each slice will have dedicated resources in the core, including guaranteed bandwidth and low latency. The plan is to use the SRv6 network programming concept to steer traffic into different slices. The provider wants to ensure that slice isolation is maintained end-to-end, including at the egress PE where traffic is handed off to the customer. However, during testing, they observe that traffic from one slice is incorrectly entering another slice's queue on an intermediate node, causing performance interference. The intermediate node is a transit router that does not terminate SRv6 but performs 'SID-based forwarding'. Which mechanism is most likely missing to ensure slice isolation on transit nodes?
Hard191A network engineer is configuring MPLS LDP on a new router. After enabling LDP globally and on the interface, the LDP session does not establish. The IGP (OSPF) is fully operational. What should the engineer verify first?
Easy192A network engineer needs to design a multicast solution for IPTV distribution across a service provider network. Which protocol is best suited for building a shared distribution tree where the RP is dynamically elected?
Hard193A service provider is migrating from LDP to Segment Routing (SR) in the core. They need to support MPLS forwarding without maintaining LDP sessions. Which SR data plane is appropriate?
Hard194In IOS XR, what is the commit/rollback configuration model?
Medium195An engineer notices that an MPLS LSP in the core is not establishing. Which troubleshooting step should be performed first?
Medium196Which THREE are characteristics of EVPN? (Choose three.)
Medium197Drag and drop the steps to configure OSPF on a Cisco IOS router into the correct order.
Medium198A metro Ethernet provider needs to scale customer VLANs beyond the 4,096 limit by encapsulating customer VLAN tags with an outer service provider tag. Which IEEE standard is used?
Hard199Which QoS mechanism is most effective for preventing congestion on a service provider edge link when traffic exceeds the link capacity?
Easy200Refer to the exhibit. This JSON policy is used for Segment Routing Traffic Engineering. What is the purpose of the 'color' attribute?
Easy201A service provider is deploying Segment Routing Traffic Engineering (SR-TE) to optimize traffic flows. Which mechanism is used to steer traffic into an SR-TE policy?
Hard202A service provider is designing a new MPLS L3VPN service. The customer requires that their VPN traffic be isolated from other customers and that the provider edge routers maintain separate routing tables for each VPN. Which architectural component is essential for this separation?
Medium203An SP is planning to offer L3VPN services. Which TWO components are essential for BGP/MPLS IP VPN operation?
Medium204In an SR network, which configuration is required to activate TI-LFA for link protection?
Hard205An SP uses Cisco NSO for automation. Which protocol does NSO typically use to push configuration changes to network devices?
Hard206In an MPLS VPN, what label operation does the egress PE perform on the VPN packet before forwarding it to the CE?
Easy207Which MEF service type is used for multipoint-to-multipoint Ethernet connectivity, such as a corporate LAN extension across multiple sites?
Easy208An operator notices that a new MPLS-TE tunnel is not being established. The tunnel configuration includes a dynamic path option and a bandwidth of 100 Mbps. The network uses RSVP-TE with CSPF. The link-state database shows sufficient reservable bandwidth on all links along the calculated path. What is the most likely cause of the tunnel establishment failure?
Hard209In the context of network slicing for 5G, which type of slice is optimized for massive IoT with low data rates and high connection density?
Medium210A service provider is implementing IPv6 transition in its core. Which transition mechanism is recommended for carrying IPv6 over an existing MPLS/IPv4 backbone without dual-stacking all routers?
Hard211Which protocol is used to discover MPLS peers for LDP session establishment?
Easy212An SP is designing a core network using Cisco CRS routers running IOS XR. They require process separation to ensure that a failure in the BGP process does not affect OSPF operations. Which IOS XR architectural feature provides this capability?
Hard213Which access technology uses orthogonal frequency-division multiplexing (OFDM) and is commonly deployed for high-speed internet over copper telephone lines?
Medium214An MPLS Traffic Engineering LSP fails to establish. The RSVP signaling shows 'PathErr: Admission Control Failure'. The link has sufficient bandwidth but the headend reports a lack of resources. What is the most likely cause?
Medium215A service provider offers IPTV services using multicast. The network uses Multicast VPN (MVPN) with Rosen GRE encapsulation (Profile 1) in an MPLS L3VPN environment. The Provider Edge (PE) routers participate in both the default MDT and data MDT for high-bandwidth streams. Recently, a new channel was added, and it uses a data MDT. The content server is attached to a PE that is acting as a multicast source. Other PEs are receivers. Upon adding the channel, some receivers report missing packets. The network engineer checks the PEs and notices that the data MDT group address is being advertised via BGP as an MDT SAFI route, but some PEs are not joining the data MDT. The source PE's multicast routing table shows that it believes data MDT is active. Which architecture issue is most likely preventing some PEs from joining the data MDT?
Hard216A service provider wants to offer a service where a customer site can communicate with multiple other sites in a full mesh over MPLS. Which L2VPN technology is most appropriate?
Medium217An ISP wants to create separate virtual networks over a shared physical infrastructure to serve mobile broadband (eMBB), IoT (mMTC), and mission-critical services (uRLLC). Which technology enables this segmentation with per-slice resource guarantees?
Hard218Refer to the exhibit. The router has an outgoing label of 'Pop' for prefix ***********. What does this imply?
Medium219A service provider wants to prioritize voice traffic over data traffic on a PE-CE link. Which QoS mechanism should be applied at the PE ingress to classify packets?
Easy220A small service provider is deploying MPLS in its core network for the first time. They have a simple topology: three P routers in the core and two PE routers connecting customers. They have configured LDP on all interfaces and OSPF as the IGP. They also configured a basic L3VPN for a customer with a single CE attached to each PE. The customer reports that they can ping between CEs for a few minutes, but then the connectivity drops. After a few seconds, it returns. This pattern repeats every few minutes. The engineer checks the LDP neighbors and sees that all LDP sessions are up. The OSPF adjacencies are stable. The engineer also notices that the pings time out exactly when the LDP graceful restart timer is expiring on one of the P routers. What is the most likely cause?
Easy221Which access technology uses wavelength division multiplexing to provide symmetric gigabit speeds in fiber-optic networks?
Easy222An engineer is troubleshooting a BGP route propagation issue. The customer is receiving a default route from upstream provider, but the route is not being installed in the routing table. The BGP table shows the route is valid but not best. What is the most likely cause?
Medium223An SP is designing a metro Ethernet network using Q-in-Q. A customer uses VLAN ID 100 on their network, and the SP assigns service VLAN 200. Which frame format is used on the SP network?
Hard224An SP is deploying EVPN with VXLAN encapsulation in a data center interconnect. The design requires that the control plane for MAC/VTEP learning is based on BGP. Which BGP address family must be configured?
Hard225A service provider is deploying a new metro Ethernet network and needs to support multiple customer VLANs over a single physical link without overlapping VLAN IDs. Which technology should be used at the access layer to achieve this?
Medium226Which access technology is commonly used in service provider networks to deliver high-speed internet over existing telephone lines?
Easy227Refer to the exhibit. An engineer configures MPLS LDP on a router. The router has two interfaces with IP addresses 10.0.0.1/30 and 10.0.0.5/30. The engineer notices that LDP sessions are not established. The OSPF neighbor adjacencies are up. What is the most likely cause?
Hard228Which TWO are characteristics of Segment Routing?
Easy229An SP engineer notices that BGP routes from a CE are not being installed in the VRF routing table, although the BGP session is established. The VRF configuration includes route-target import 100:1. The CE is sending routes with RT 100:1. What is the most likely cause?
Medium230A large service provider operates an MPLS L3VPN network with multiple Route Reflectors (RRs) in the core. The network uses BGP as the control plane for both IPv4 unicast and VPNv4 routes. Recently, one of the RRs started flapping, causing route withdrawals to many clients. The network architect wants to improve stability. The RRs are fully meshed with each other and clients are configured as route-reflector clients. The RRs have both IPv4 and VPNv4 address families enabled. Which action should be taken to minimize the impact of an RR failure?
Easy231Refer to the exhibit. Based on the exhibit, what is the most likely reason for no label bindings?
Medium232An SP uses Cisco ASR 9000 routers with IOS XR. Which statement correctly describes the commit/rollback configuration model in IOS XR?
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