Cisco 350-501 Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) Exam Practice Test

R1

router bgp 100

address-family ipv4

nei 172.16.0.2 route-map R1-TO-R2 in

network 10.1.1.1 mask 255.255.255.255

copy run start

R2

router bgp 200

address-family ipv4

network 10.2.2.2 mask 255.255.255.255

nei 172.16.0.1 route-map R2-TO-R1 in

copy run start

 The BFD (Bidirectional Forwarding Detection) interval configuration on an interface is automatically disconnected when the BFD-configured subinterface is removed. This is because BFD sessions are tied to the specific subinterface, and removing it will terminate the BFD session associated with that subinterface.

References: The information is based on the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course, which covers the configuration, verification, troubleshooting, and optimization of Service Provider IP network infrastructures, including BFD implementation

In the context of VPLS (Virtual Private LAN Service) configuration, the engineer should perform additional configurations to enable the virtual switch instance. The correct answer is Option A, which likely involves configuring interface VLAN and associating it with xconnect vfi to establish end-to-end LAN connectivity between customer’s remote offices. This is essential for enabling VPLS, which allows geographically dispersed sites to be connected over a service provider’s network as if they were on the same local area network.

References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Cisco SPCOR Training & Certification

To reduce network usage and minimize leave latency for users connected to VLAN 76, the configurations should focus on efficient multicast traffic management. Option A likely involves enabling IPv6 MLD snooping, which restricts multicast traffic to only the ports that have members interested in receiving the traffic, thus reducing unnecessary network usage. Option C might include configuring fast-leave processing, which allows the switch to immediately stop forwarding multicast traffic to a port when the last member of a multicast group leaves, reducing leave latency.

References := Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR)

In the context of configuring L2VPN over MPLS, the xconnect statement is essential. It specifies the peer router and virtual circuit ID, creating the connection between two customer edge routers over the service provider’s MPLS network. Without the xconnect statement, there’s no association between the attachment circuits and pseudowire, leading to the failure of the L2VPN service.

References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Cisco SPCOR Training & Certification

The URL in the exhibit is used with REST API to send a message to the APIC (Application Policy Infrastructure Controller) to perform an operation on a managed object or class operator. In Cisco’s ACI (Application Centric Infrastructure), REST API requests are used for managing, configuring, and retrieving data from the APIC. The URL structure typically includes the IP address of the APIC and specific paths that refer to objects or classes within the ACI fabric. References: Implementing and Operating Cisco Service Provider Network Core Technologies source documents or study guide

 To establish LDP peering with the loopback IP address as its Router ID, both RA and RC need to configure their LDP router IDs to use their respective loopback addresses. This is done by applying the ‘mpls ldp router-id loopback0’ command on both routers. This configuration ensures that LDP peering uses the loopback addresses, which is a requirement for the service-provider core network.

References := This explanation is based on the concepts outlined in Cisco’s Implementing and Operating Service Provider Network Core Technologies (SPCOR) course, which provides in-depth knowledge on service provider infrastructure. For further study, refer to the official Cisco documentation and training materials available on the Cisco Learning Network Store.

After a router reload, BGP sessions may fail to re-establish due to incorrect source interface configurations for BGP sessions. Since EBGP multihop has been configured, it’s essential that the BGP session uses the correct source interface for establishing the connection. By configuring the neighbor update-source command with the loopback interface on R2, the BGP session will use the stable loopback address rather than the physical interface, which can change state. This ensures that the BGP session remains stable and is not affected by interface states. References: BGP Troubleshooting Cheat Sheet With Examples - Catchpoint2, BGP session stuck in Idle state after NSRP failover - Juniper Networks3, BGP Session is Disconnected - Network Playbook

The correct configuration for deploying VRF on ASBR router R1 to have connectivity over an MPLS VPN inter-AS Option AB network is found in option C. This involves configuring the interface with the commands shown, including setting the interface ethernet, applying IP VRF forwarding, and enabling MPLS BGP forwarding. These steps ensure that the interface is properly configured for VRF and can support MPLS VPN inter-AS communications effectively. References := Implementing and Operating Cisco Service Provider Network Core Technologies

PCE – 1,2,5

PCC- 3,4

To direct traffic from R3 to R4 via R1, the weight attribute on R3 can be set higher for the route through R1 compared to other routes. Weight is a Cisco-specific BGP attribute that determines the preferred path when multiple routes to the same destination exist. It is local to the router on which it is configured and not advertised to other BGP peers.

References :=

• Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials.

 To complete the implementation of the route map “ciscotest” for filtering routes to a BGP peer, the engineer must attach the route map to the BGP neighbor statement in the inbound direction. This will apply the specified filtering criteria to routes received from the BGP neighbor, thereby limiting access to restricted areas within the network as intended by the client. References := The Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials discuss the configuration of route maps and their application to BGP neighbors for route filtering purposes

In the given scenario, the goal is to restrict users on the network between R1 and R2 from accessing the external network through R5, while still allowing them access to all resources within the administrative domain. The correct approach is to configure an Access Control List (ACL) that permits traffic to all internal networks and denies traffic to any external address. This ACL should be applied to the R2 interface that connects to R1 in the ingress direction. By doing so, traffic originating from users between R1 and R2 destined for external networks will be blocked, while internal traffic will be allowed.

References: This explanation is derived from the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) study materials, which cover the configuration and application of ACLs in a service provider network environment.

https://www.cisco.com/c/en/us/p roducts/collateral/switches/nexus-9000-series-switches/guide-c07-734107.html

 BGPsec enhances BGP by adding a layer of security for the AS path attribute. When BGPsec is implemented, updates from eBGP peers include a BGPsec attribute sequence with a public key hash and digital signature. This ensures the authenticity and integrity of the AS path, preventing unauthorized AS numbers from being inserted. References: = Implementing and Operating Cisco Service Provider Network Core Technologies course materials. 

The configuration in the exhibit shows a route policy named “ciscotest”. According to this policy, if the destination is in acl10, then the traffic will pass without any changes. However, if the destination is not in acl10 (else condition), then the local preference will be set to 300 before it passes through. This means option C is correct as it states that if traffic matches acl10, it’s allowed without any change to its local-preference; otherwise (if not matching acl10), its local-preference is set to 300.

LDP session protection capability is a feature that maintains LDP bindings when a link fails, using LDP Targeted Hellos to protect LDP sessions. Without the specific exhibit, it’s not possible to determine which router has LDP session protection enabled but session hold up is not active.

References: Information about MPLS LDP Session Protection can be found in Cisco documentation, such as the Cisco IOS MPLS Configuration Guide.

 Implementing CSC VPN services for a new backbone carrier provides several benefits. Firstly, it maintains a single backbone network, which simplifies the VPN implementation to customers (A). This eliminates the need for each Level 2 carrier to create and maintain a separate backbone network, thus lowering maintenance costs and simplifying management operations. Secondly, it supports a scalable growth strategy that services multiple customers efficiently (D). The Level 1 carrier can use one backbone network to provide VPN and Internet services for multiple Level 2 carriers, increasing revenues and efficiency.

References: The benefits of implementing CSC VPN services are detailed in the Huawei IP Encyclopedia, which explains the Carrier’s Carrier (CSC) networking solution in BGP/MPLS IP VPN2.

 To ensure that traffic for the prefix 192.168.1.1/32 travels via the alternate path R6-R5, a route-map with a higher local preference should be applied inbound on R3 for neighbor R6. This will make the path through R6-R5 more preferable, thus meeting the requirement. References := Implementing and Operating Cisco Service Provider Network Core Technologies

RSVP (Resource Reservation Protocol) is used with MPLS (Multiprotocol Label Switching) traffic engineering tunnels primarily to reserve bandwidth along the path of the tunnel. This ensures that sufficient resources are allocated for the traffic to meet quality of service requirements, which is crucial for maintaining the performance of critical applications that traverse the network. References := For more information on RSVP and MPLS traffic engineering, refer to the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials, which provide detailed explanations on how these technologies work together to optimize network traffic1.

RSVP-TE Fast Reroute (FRR) is a mechanism that provides protection switching for MPLS TE LSPs. The Point of Local Repair (PLR) will prefer to use a next-hop (NHOP) backup tunnel over a next-next-hop (NNHOP) backup tunnel when both are available. This preference is due to the fact that NHOP backup tunnels can provide faster rerouting around the failure point, minimizing traffic disruption and packet loss.

References: The information is based on the RSVP-TE FRR deployment considerations from the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials.

The SPT threshold set to infinity causes multicast traffic to permanently stay on the shared tree and not switch to the source tree. In multicast routing, the Shortest Path Tree (SPT) threshold determines when a router should switch from receiving multicast traffic on the shared tree to receiving it on a source tree. Setting the SPT threshold to infinity means that the router will always receive multicast traffic on the shared tree

To influence inbound path selection when implementing BGP in a multihomed architecture, an engineer must configure a route map with the AS_PATH attribute. The AS_PATH attribute is used to manipulate the path information to make certain routes more or less attractive, thereby influencing the decision-making process for inbound traffic.

The correct configuration to ensure that SNMP servers acknowledge the notifications they receive is to use the snmp-server host command with the Informs keyword. This configuration sends Inform requests instead of Trap messages. Unlike Traps, Inform requests are acknowledged by the receiving SNMP server, ensuring that the notification has been received. If an Inform request is not acknowledged, the SNMP agent resends the notification.

References: The information is based on the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) training, which teaches how to configure, verify, troubleshoot, and optimize next-generation, Service Provider IP network infrastructures.

The configuration snippet in the exhibit shows that BGP summarization is configured with the “aggregate-address” command followed by an IP address and a subnet mask, and then the “summary-only” and “as-set” options. The IP address is 192.168.0.0, and the subnet mask is 255.255.0.0, which corresponds to a /16 prefix length (indicating that the first 16 bits of the IP address are the network portion). However, there seems to be a typo in option B as it’s not a valid IP address format; hence option A is correct with an assumption of typo error.

References: Implementing and Operating Cisco Service Provider Network Core Technologies source documents or study guide

In this scenario, when edge routers at different regional sites are connected over a global carrier backbone, MP-eBGP must be run between routers to exchange customer VPNv4 routes. This is essential for enabling communication between customer sites located in different regions while utilizing a global carrier backbone service. References: Implementing and Operating Cisco Service Provider Network Core Technologies source documents or study guide

•  The PCE (Path Computation Element) communicates with the PCC (Path Computation Client) using the PCEP. PCEP is responsible for path computation and signaling in MPLS networks.
• References: Implementing and Operating Cisco Service Provider Network Core Technologies course materials.

 In OSPF, for two routers to form an adjacency, they must have matching MTU sizes on their connecting interfaces. If the MTUs are mismatched, OSPF adjacency will be stuck in the EXSTART/EXCHANGE state because OSPF hello packets will not be exchanged between the routers. In this case, both routers R1 and R2 are stuck in EXCHANGE/EXSTART state due to mismatched MTU sizes as indicated in the exhibit. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Cisco

• Area 10 should receive inter-area routes and support mutual redistribution with the extranet but not receive the default route (::/0). This requirement does not align with any of the stub or NSSA configurations, as these would restrict the type of routes received.
• Area 11 should only receive the default route from the ABR and not support external route redistribution or advertise inter-area routes. Configuring Area 11 as an NSSA (Not So Stubby Area) with the no-summary option on R7 and as NSSA on XR31 would prevent inter-area routes from being advertised into Area 11. Additionally, the default-information-originate command on R7 would generate a default route into Area 11, fulfilling the requirement.

References: = The explanation is based on the OSPFv3 configurations and area types as described in the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials. 

The correct configuration for PE1 to connect AS 200 of the service provider with AS 100 of enterprise ABC using BGP, considering the VRF RT 100:10 is already configured, would involve setting up BGP with the correct neighbor and route distinguisher settings. Option C is likely the correct choice as it specifies the BGP neighbor to be within the enterprise ABC’s AS 100 and includes the address family configuration necessary for VRF-aware BGP sessions. References := The Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials provide detailed instructions on configuring BGP in a service provider environment, including the use of VRFs and route distinguishers. For more information, please refer to the official Cisco documentation and course materials related to SPCOR1.

 The requirement is for R2 to delay sending BGP updates to R5 for multicast traffic by 30 seconds. This can be achieved by configuring the advertisement interval for IPv4 multicast traffic on R2, which controls the frequency of sending BGP updates for multicast routes. References := Cisco SPCOR

 To achieve this, we need to apply an access control list (ACL) on PE-R9 that permits SSH traffic from the management network 192.168.0.0/16 while denying other traffic. The correct ACL configuration is as follows:

access-list 100 permit tcp 192.168.0.0 0.0.255.255 any eq 22

access-list 100 deny ip any any

• The first line permits TCP traffic from the management network to any destination with destination port 22 (SSH).
• The second line denies all other IP traffic.

References:

• Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) v1.0 course materials.
• Cisco Learning Network: SPCOR Training Videos
• Cisco Learning Network: Service Provider Training

In a multivendor network environment, it is essential to configure OSPF NSF with the IETF standard to ensure compatibility across different vendor devices. The command router ospf 1 nsf ietf enables OSPF NSF capability using the IETF standard, which facilitates uninterrupted forwarding during a route processor switchover.

References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - OSPF Nonstop Forwarding section.

The command “traceroute mpls ipv4 10.20.0.1/32 ttl 4” is used to trace the route that packets take to get from the source to the destination in an MPLS network, specifically for IPv4 addresses with a maximum of 4 hops (Time To Live). This command will provide information on all labels and hop-by-hop IP addresses for the specified destinations, meeting the requirements stated in the question.

References := For more detailed information, you can refer to the Implementing and Operating Cisco Service Provider Network Core Technologies training, which covers the configuration, verification, troubleshooting, and optimization of Service Provider IP network infrastructures, including MPLS operations

If RC is a stub router in an OSPF network, it requires a default route to be injected so that it can send traffic outside the OSPF domain. In OSPF, stub routers do not have any routes external to the OSPF domain in their routing tables. To allow these routers to reach networks outside of their OSPF domain, a default route should be injected into the stub area by the Area Border Router (ABR). This allows all routers in the stub area, including RC, to forward traffic for unknown destinations to the ABR, which then forwards it appropriately. References: Implementing and Operating Cisco Service Provider Network Core Technologies source documents or study guide

Router 1 is the trigger router in a Remote Triggered Black Hole (RTBH) implementation. In the configuration provided, Router 1 has a static route to null0 for network 192.168.1.0/24 with a tag of 1, which is used to drop traffic destined to this network, effectively mitigating DDoS attacks. The route-map “ddos” matches this tag and sets local preference and community accordingly. The BGP process redistributes this static route based on the “ddos” route-map, signaling other routers in the network to drop traffic destined for the attacked network. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - RTBH section1.

YANG (Yet Another Next Generation) is a data modeling language used primarily for the configuration and state data of network elements. It is closely associated with the NETCONF (Network Configuration Protocol) for which it models configuration data. YANG provides schemas that define how data is structured and transported by NETCONF operations. It also shapes the state data of network elements, allowing for a standardized format for representing the operational state of devices. References: YANG is defined in RFCs such as RFC 6020 and RFC 7950, which outline its role in NETCONF operations and its capabilities in modeling both configuration and state data.

The command channel-group 1 mode desirable configures the switch port to actively send PAgP packets to negotiate forming an EtherChannel. PAgP is a Cisco-proprietary protocol used in the automatic creation of EtherChannel links. When set to ‘desirable’, the port actively attempts to form an EtherChannel, which means it sends PAgP packets without waiting for the connected peer to initiate the negotiation.

References: For more information on link aggregation and EtherChannel configurations, refer to the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials, specifically the sections covering EtherChannel and PAgP.

To achieve the origination of a default route based on the condition of the application server being up, a route map policy needs to be applied. This policy should match the condition of the server’s status and then use the default-information originate command to originate the default route with the specified metric type and value on router RL.

References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - OSPF Route Map Policy section.

When implementing traffic shaping on a network, the goal is to control the rate of traffic being sent into the network to avoid congestion. This is done by buffering excess packets and then scheduling them to be sent out at a steady rate.

Option A is correct because traffic shaping requires a queue with sufficient memory to buffer excess packets. When the traffic rate exceeds the configured maximum rate (shaping rate), the excess packets are temporarily stored in the queue until they can be sent out, ensuring a smooth flow of traffic without overwhelming the network1.

Option B is also correct as traffic shaping involves configuring token values in bytes. Tokens are used to represent permission to send a certain amount of data. The token bucket is filled with tokens at a steady rate, and packets can only be sent if there are enough tokens in the bucket. The token values determine the size of the bucket and the rate at which it is refilled, which in turn controls the rate of traffic1.

Option C is incorrect because packet remarking for excess traffic is not a component of traffic shaping. Packet remarking is typically used in conjunction with policing, where packets that exceed the rate limit can be remarked to a lower priority for downstream handling1.

Option D is incorrect in the context of traffic shaping. While a scheduling function is used to handle the packets that are delayed due to buffering, the scheduling itself is not part of the shaping mechanism but rather a function of the queuing system that works alongside shaping1.

Option E is incorrect as it pertains to traffic policing, not shaping. In traffic policing, packets that exceed a certain threshold are discarded or remarked, whereas shaping delays excess packets by buffering them1.

References: The information provided here is based on the Quality of Service (QoS) Configuration Guide from Cisco, which details the components and implementation of QoS, including traffic shaping1.

To ensure that critical, time-sensitive data from the server on R1 to the host on R3 is always prioritized, especially during congestion, the network engineer should implement a Quality of Service (QoS) strategy that uses strict priority queuing. This QoS mechanism ensures that traffic marked as high priority is transmitted first, while other traffic may be queued or dropped if necessary. Strict priority queuing is designed for scenarios exactly like this, where certain traffic must be guaranteed bandwidth to meet time-sensitive requirements. References := For more detailed information on QoS strategies and classification, refer to the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials, specifically the sections discussing QoS mechanisms and their implementation in service provider networks. Additionally, Cisco’s official documentation on QoS provides comprehensive guidelines on configuring and applying strict priority queuing to ensure bandwidth for critical traffic.

 The configuration shown is for the head-end router of a Cisco MPLS TE tunnel with segment routing. The commands included, such as “mpls traffic-eng tunnels” and “segment-routing mpls,” indicate that this is set up for a head-end router in an MPLS TE tunnel. There is no requirement for an explicit path or OSPF to be running, which eliminates options A and B. Option C is also incorrect as there’s no indication of a dynamic path configuration present.

References: The Implementing and Operating Cisco Service Provider Network Core Technologies course provides a deep dive into Service Provider technologies, including MPLS traffic engineering and segment routing, which are relevant to this configuration

The configuration applies a QoS policy to the pos0/2/0/0 interface, which affects traffic as it exits the interface. The policy map “ciscopolicy” references the class map “ciscotest”, where traffic matching the class map criteria will be remarked. The command set precedence 1 within the class map “ciscotest” indicates that the traffic will be remarked to IP precedence 1. Therefore, the correct effect of this configuration is that traffic identified by the “ciscotest” class map will be remarked from its original IP precedence to IP precedence 1 when it exits the pos0/2/0/0 interface.

References: = This explanation is based on the QoS configuration practices as outlined in the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials.

Cisco MPLS TE (Traffic Engineering) tunnels provide a way to optimize traffic routing within an MPLS network. However, there are certain constraints to be aware of:

• QoS-aware tunneling: Unfortunately, Cisco MPLS TE tunnels do not inherently support Quality of Service (QoS) awareness. This means that the tunnels themselves do not directly consider QoS parameters when making routing decisions. QoS policies must be applied separately at the network level, and the TE tunnels do not inherently take QoS into account during path selection.
• Tunnels spanning multiple OSPF areas: Contrary to option A, Cisco MPLS TE tunnels can indeed span multiple OSPF areas. The use of OSPF areas does not inherently restrict the creation of MPLS TE tunnels across area boundaries.
• ISIS metrics: Option B is incorrect. When using ISIS (Intermediate System to Intermediate System) as the Interior Gateway Protocol (IGP), newer-style metrics (such as wide metrics) are supported. Older-style metrics are not the only option.
• Tunnels over IP unnumbered links: Option C is also incorrect. Cisco MPLS TE tunnels can be configured over IP unnumbered links, allowing efficient use of IP addresses.

In summary, the primary constraint is the lack of built-in QoS awareness within MPLS TE tunnels.

References:

• Implementing an MPLS VPN over TE Tunnels - Cisco Support
• Configuring Basic MPLS TE - Cisco NX-OS

Cisco MPLS Traffic Engineering (TE) tunnels necessitate a link-state routing protocol like OSPF or IS-IS because these protocols use Shortest Path First (SPF) calculations. The tunnel endpoints leverage these SPF calculations to implement the tunnel, ensuring an efficient and optimized path through the network. This is essential for MPLS TE, which aims to optimize network resource utilization and improve traffic distribution across the network.

References: Cisco Community, Cisco Documentation

 In a multi-vendor environment with PIM-SM, the Bootstrap Router (BSR) mechanism is used for devices to dynamically learn the Rendezvous Point (RP). BSR is a protocol feature that automates the dissemination of RP information in a PIM domain. This feature allows routers to automatically discover the RP set in use, which simplifies configuration and management compared to static RP configurations or Auto-RP. References: Implementing and Operating Cisco Service Provider Network Core Technologies source documents or study guide

 The multicast implementation shown in the exhibit indicates that R2 is elected as the RP (Rendezvous Point) for the domain. This is inferred from the configuration commands which show R2 set up as a Bootstrap Router (BSR) candidate. In PIM-SM (Protocol Independent Multicast Sparse Mode), the BSR is responsible for announcing the RP-set to all routers in the PIM domain, and since R2 is the only BSR candidate, it effectively becomes the RP by default unless there are other configurations not shown in the exhibit.

References: The explanation is based on the concepts outlined in the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course, which covers multicast routing and PIM-SM operations in detail. For more information, you can refer to the official Cisco SPCOR training and certification resources.

The correct action to complete the configuration for connecting two offices via an MPLS L3 VPN is option A. This involves configuring the network 172.16.10.0 and using the redistribute-internal static commands under the BGP address family for Customer_A in the global BGP configuration on R1. In an MPLS L3 VPN, the provider edge (PE) router, which is R1 in this scenario, redistributes customer routes into BGP. The PE router then advertises these routes to other PE routers within the MPLS network using MP-BGP, allowing for the establishment of the VPN.

References :=

• Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials and official Cisco documentation.

 To address the issue of BGP session flapping between ISP A and ISP B, the networking team at ISP A should implement BGP route dampening. This feature helps stabilize the network by suppressing the advertisement of flapping routes. The command bgp dampening 15 700 1500 30 will set the parameters for route dampening, where routes that flap will be suppressed for 30 minutes. This action will prevent the constant advertisement and withdrawal of unstable routes, thus improving the stability of the network. References := For further details on BGP route dampening and its configuration, the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials and Cisco’s official documentation provide comprehensive guidance.

The REST API script in the exhibit is used to configure a VRF (Virtual Routing and Forwarding) instance. In the script,  defines a tenant named “customer”, and  creates a VRF named “customervrf” within that tenant. A VRF allows multiple instances of a routing table to co-exist within the same router at the same time, enabling network paths to be segmented without requiring multiple routers. References: Implementing and Operating Cisco Service Provider Network Core Technologies source documents or study guide.

• To prevent packet loss when IGP (Interior Gateway Protocol) and LDP (Label Distribution Protocol) are not synchronized, enabling MPLS LDP IGP synchronization is crucial. This synchronization ensures that the IGP routing protocol (such as OSPF or IS-IS) waits until LDP convergence is completed before advertising labels for MPLS traffic. It helps maintain consistency between the IGP and LDP databases.
• References: Implementing and Operating Cisco Service Provider Network Core Technologies course materials.

 For OSPF, the subnet mask must match between two devices on the same network segment to form an adjacency, as it defines the network’s address range. The hello timer setting is crucial for the OSPF Hello protocol, which is used for neighbor discovery and maintaining neighbor relationships. Finally, the area number must be the same because OSPF uses areas to define a hierarchy within the network, and routers within the same area share routing information.

References: OSPF is a link-state protocol that requires certain parameters to match for a successful adjacency. This includes the subnet mask, hello timer, and area number, which are fundamental to OSPF’s operation and ensure that routers can communicate effectively within the same area

The issue of the OSPF domain receiving only the 172.17.1.0/24 route and not the default route 0.0.0.0/0 can be resolved by configuring OSPF to propagate default routes. Let’s take a look at the options:

• Option A: The configuration includes the following commands:
• router ospf 1
• default-information originate
• end

This configuration generates a default route into the OSPF domain, which is missing in this scenario.

 Transport Layer Security (TLS) is essential for securing RESTCONF communications on network devices. TLS provides a secure channel with encryption, ensuring that the data exchanged between the client and server remains private and integral. For RESTCONF to utilize TLS, it requires proper certificates for authentication. These certificates confirm the identity of the devices involved in the communication, preventing man-in-the-middle attacks and unauthorized access2.

References := Programmability Configuration Guide, Cisco IOS XE Amsterdam 17.1.x - RESTCONF Protocol2.

When a prefix list is applied to a BGP neighbor, it filters routes based on the specified conditions. In this scenario, the prefix list is designed to permit prefixes that are equal to or longer than /17 but shorter than or equal to /19. Therefore:

• A: 192.168.0.0/19 is denied because it falls outside the specified range.
• D: 192.168.0.0/16 is denied as it is shorter than the minimum length of /17.
• E: 192.168.0.0/16 is permitted because it is the exact prefix specified in the prefix list, and the ge and le modifiers apply to more specific routes derived from this prefix. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Cisco official courseware.

The configuration command xconnect 192.168.0.1 12 encapsulation mpls pw-class cisco is used to set up a pseudowire connection to a remote peer at IP address 192.168.0.1 using MPLS encapsulation. The pw-class cisco refers to a pseudowire class named ‘cisco’ that defines the parameters for the MPLS pseudowire. This configuration is part of setting up Layer 2 VPNs, which are often used in service provider networks to extend services such as Ethernet, ATM, or Frame Relay over an MPLS network.

References: For more detailed information, please refer to the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials, specifically the sections covering MPLS and Layer 2 VPNs.

The correct configuration to reduce LDP LIB size and advertise label bindings for the /32 loopback IP space only is to use an IP prefix-list that specifies the /32 prefix length and then configure MPLS LDP to allocate labels for these prefixes. The ip prefix-list LOOPBACKS seq 5 permit 0.0.0.0/0 le 32 command creates a prefix-list named LOOPBACKS that allows any IP address with a prefix length less than or equal to 32. The mpls ldp label allocate global prefix-list LOOPBACKS command then instructs the router to allocate labels for all prefixes permitted by the LOOPBACKS prefix-list, which in this case, would be all /32 prefixes. References: The explanation is based on the concepts covered in the SPCOR course, specifically the sections on MPLS LDP configuration and optimization. For more detailed information, refer to the official Cisco SPCOR course materials and documentation available at Cisco’s official training page.

 In a Unified MPLS routing architecture with partitioned IGP domains, it is essential to ensure that the iBGP Labeled Unicast address families are correctly configured to facilitate the exchange of VPNv4 routes directly between PE routers. In this case, ABR R102 should be configured with the address family-level configuration depicted in Option A to support this architecture. This configuration ensures that R101 can peer with both R102 and R103, and similarly, R201 can peer with R202 and R203 using iBGP Labeled Unicast address families. References := Implementing and Operating Cisco Service Provider Network Core Technologies

Ansible is widely recognized as a robust network automation tool that facilitates provisioning, configuration, and management of network devices. It uses simple, human-readable YAML syntax for its playbooks, making it easy to define tasks and orchestrate workflows for automated network operations1.

 In the context of Implementing and Operating Cisco Service Provider Network Core Technologies, LDP-IGP Synchronization is configured to ensure that the IGP and LDP convergences are synchronized. Option C is correct because it shows the configuration where router ISIS 1 is being configured with MPLS LDP sync, but not on a specific interface, ensuring that LDP is operational on all interfaces where IS-IS is enabled before routes are advertised. References := Cisco

The command nsf ietf helper strict-lsa-checking is used to configure the router to terminate the OSPF graceful restart process if it detects any changes in the LSA during the restart. This ensures that the network remains stable and consistent by preventing the use of outdated or incorrect routing information.

In the context of Cisco’s Implementing and Operating Service Provider Network Core Technologies, the UCS Series is typically where OpenStack components would be hosted. OpenStack is a cloud operating system that controls large pools of compute, storage, and networking resources throughout a data center, all managed through a dashboard that gives administrators control while empowering their users to provision resources through a web interface.

References: Cisco SPCOR training materials and documentation provide detailed information on the implementation and operation of service provider technologies, including the hosting of OpenStack components on the UCS Series.

 In the context of Cisco IOS XR software, the configuration under Option D is appropriate for adding an interface to a bundle using LACP (Link Aggregation Control Protocol). The configuration specifies two Ten Gigabit Ethernet interfaces (TenGigE0/1/0/5 and TenGigE0/1/0/6) with descriptions indicating they are part of “bundle_1_link”. Both interfaces are assigned to “bundle id 1” with a load interval of 30 seconds, ensuring they are part of the same link aggregation group and share traffic load.

MPLS LSP ping is a utility for locating faults within an MPLS network, specifically for Label Switched Paths (LSPs). It helps in verifying the LSPs in the MPLS network. The utility sends echo requests to the destination, and if the path is complete, echo replies are received. References := Cisco

To inject a default route into the MP-BGP address family for a dedicated VRF, you would typically need to:

• Configure a static default route in the VRF using the ip route vrf 0.0.0.0 0.0.0.0  command.
• Redistribute the static route into BGP using the redistribute static command under the BGP VRF configuration.

The RPL script in the image is used to filter BGP routes based on the AS path. The script includes a condition that checks if the AS path contains ‘7077’ using a regular expression (ios-regex ‘777$’). If this condition is met, the route is passed; otherwise, it would be denied by default. Therefore, this script allows routes from AS 7077 and denies others.

References := For specific references, please consult the Implementing and Operating Cisco Service Provider Network Core Technologies source book or study guide, as I am unable to provide direct links or access content from external websites.

The correct configuration for extending the layer 2 domain between the company’s two locations involves setting up the interface with L2 transport, specifying the encapsulation method as dot1q with the VLAN tag of 12, and applying the appropriate rewrite ingress tag rules. This setup ensures that the VLAN tag is preserved across the service provider’s core, maintaining the layer 2 domain continuity.

References := Implementing and Operating Cisco Service Provider Network Core Technologies

 The issue described involves packets being dropped when sent from the application server to the access site. Since OSPF and BGP peerings are confirmed to be operational, the problem likely lies within the route advertisement. Allowing 172.16.20.1 in the BGP advertisement on R3 by adjusting the route-map will likely resolve the issue, ensuring that traffic destined for 172.16.20.1 is not being inadvertently filtered or blocked.

References:

• Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course provides insights into configuring, verifying, troubleshooting, and optimizing Service Provider IP network infrastructures, which includes understanding and implementing BGP routing and route maps1.
• The official Cisco certification exam overview for SPCOR, which includes topics on BGP routing and route maps, can also serve as a reference

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/fnetflow/configuration/xe-3s/fnf-xe-3s-book/fnf-ipfix-expor t.html#d27853e197a1635

• A. Reconnect Timeout field: Specifies the time within which the LDP session should be reestablished after a failure.
• C. Graceful restart capability in OPEN message: Indicates that the router supports LDP graceful restart and is capable of maintaining its MPLS forwarding state across a control plane failure.
• D. Recovery Time field: Specifies the time that the router will maintain the MPLS forwarding state while it attempts to reestablish LDP sessions.

SNMPv3 is the most secure version of SNMP, providing both security and remote configuration capabilities. The current configuration in the exhibit shows SNMP version 2c, which is less secure. SNMPv3 introduces security features such as authentication, privacy (encryption), and access control to address the vulnerabilities associated with earlier versions of SNMP. By re-configuring to use SNMPv3, the network administrator can enhance the security for SNMP for this configuration. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Cisco SPCOR Training & Certification

1: graceful restart 2: IGP synchronization 3: session protection 4: targeted-hello accept

Solution

R3

router bgp 65413

add ipv4

nei 2.2.2.2 allowas-in

nei 4.4.4.4 allowas-in

add ipv6

nei 2001:db8:4:4:4::4 allowas-in

end

copy run start

=======================

R2

router bgp 65413

nei 1.1.1.1 as-override

nei 3.3.3.3 as-override

end

copy run start

=======================

R3

router bgp 65413

nei 10.3.4.2 remot 65412

nei 2001:db8:3:4::2 remot 65412

nei 2001:db8:4:4:4:4::4 remot 65412

nei 2001:db8:4:4:4:4::4 ebgp-multihop 10

add ip4

nei 10.3.4.2 act

ex

add ipv6

nei 2001:db8:4:4:4:4::4 activate

nei 2001:db8:4:4:4:4::4 ebgp-multihop 10

nei 2001:db8:3:4::2 act

end

copy run start

===================

R4

router bgp 65412

nei 10.3.4.1 remot 65413

nei 2001:db8:3:3:3:3::3 remot 65413

nei 2001:db8:3:3:3:3::3 ebgp-multihop 10

nei 2001:db8:3:4::1 remot 65413

add ipv4

nei 10.3.4.1 remot act

nei 10.3.4.1 prefix-limit 10

add ipv6

nei 2001:db8:3:3:3:3::3 activate

nei 2001:db8:3:3:3:3::3 ebgp-multihop 10

nei 2001:db8:3:3:3:3::3 prefix-limit 10

nei 2001:db8:3:4::1 activate

nei 2001:db8:3:4::1 prefix-limit 10

end

copy run start

The keyword ‘none’ is essential in management plane security using TACACS to ensure that authentication can still succeed when the TACACS+ server is unreachable. This fallback mechanism allows network resources to remain accessible even if the TACACS+ server fails or becomes unreachable. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Management Plane Security section.

• References: Implementing and Operating Cisco Service Provider Network Core Technologies source documents or study guide.

OSPFv3 is used for routing IPv6 prefixes and requires that each interface intended to participate in OSPFv3 has the protocol enabled. This involves specifying the OSPF process ID and the area ID that the interface belongs to. The process ID links the interface to a specific OSPFv3 process running on the router, and the area ID determines the area within the OSPF topology that the interface is part of. Without this configuration, the interfaces will not actively participate in OSPFv3 route advertisement or neighbor relationships12.

References :=

• Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials3.
• Cisco OSPFv3 configuration guides and examples

• References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) v1.0

In a multicampus network that supports video streaming, the engineer should configure the network to use IGMPv3. IGMPv3 is the version of IGMP that supports Source-Specific Multicast (SSM). SSM allows the receiver to specify the source of the multicast stream, which is particularly useful for video streaming applications. By using SSM, the network can efficiently deliver the video content from the specified source to the receivers without unnecessary traffic from other sources. References := Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) v1.01.

 The iosxr_command module in Ansible is used to issue commands on remote devices running Cisco IOS XR. This module allows network administrators to execute operational commands on Cisco routers and switches, which is essential for tasks such as retrieving information or applying configuration changes. It is a part of network automation using Ansible, which simplifies the management of network devices by automating repetitive tasks.

References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course and study guide

The core component of MDT that describes the data streamed to a collector is the encoder. In the context of Microsoft Deployment Toolkit (MDT), the encoder is not explicitly mentioned; however, the concept aligns with the process of creating and capturing images of operating systems, which involves encoding or compiling the necessary data into a deployable image.

 In Cisco Service Provider Network Core Technologies, an EVPN instance can be likened to a VRF (Virtual Routing and Forwarding). A VRF allows multiple instances of a routing table to co-exist within the same router at the same time. Similarly, EVPN provides separation between routing instances which aligns with how VRF operates.

• In Option A, the configuration correctly classifies and marks management protocols with DSCP AF23, which belongs to AF class 2 with low drop probability.
• Monitoring protocols are marked with DSCP AF13, aligning with AF class 1 and low drop probability.
• All other traffic is marked with a DSCP value of 0, as required.

References:

• Cisco’s official guide on Implementing and Operating Cisco Service Provider Network Core Technologies

 To align with customer contract SLAs and allow 10% of interface capacity on router R3 for traffic from CE1 towards the FTP server, the network engineer must apply a policy map to R1 to reserve the remaining 10% of interface bandwidth (Option C). Additionally, applying a policy map to R3 to reserve 10% of interface bandwidth (Option D) ensures adherence to the customer’s contract SLAs while utilizing the allocated bandwidth capacity. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Quality of Service section.

 The show command output indicates that the BGP neighbor is in an Idle state, which means the BGP session has not been established. Additionally, it mentions “eBGP neighbor with no inbound or outbound policy; defaults to ‘drop’”. This implies that in the absence of specific policies for route advertisement and acceptance, the default action is to drop all routes. Therefore, no routes are accepted from the neighbor 192.168.2.2, nor are any routes advertised to it, aligning with option C. References: = Implementing and Operating Cisco Service Provider Network Core Technologies course materials.

• References: Implementing and Operating Cisco Service Provider Network Core Technologies

 In OSPF (Open Shortest Path First), the Hello interval is a critical parameter for OSPF neighbor formation. It defines the frequency at which Hello packets are sent on an OSPF interface. For two OSPF routers to become neighbors, they must have matching Hello and Dead intervals. In the provided configuration, Router 1 has a hello-interval of 1 second while Router 2 has a hello-interval of 2 seconds. Adjusting them to match will reestablish the OSPF neighbor relationship between Router 1 and Router 2. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Cisco

https://www.cisco.com/c/en/us/td/docs/ios/12_2sr/12_2sra/feature/guide/srtunsel.html#wp105781 5

SOLUTION:-

R1

Config t

router isis 1

net 49.0001.0010.0001.0101.00

area-password C1sc0!

int et0/0

ip router isis 1

isis authen mode text level-2

isis circuit-type level-2

isis tag 1

int et1/0

ip router isis 1

isis authen mode text level-2

isis circuit-type level-2

isis tag 1

R2

router isis 2

net 49.0001.0010.0002.0202.00

area-password C1sc0!

int et0/0

ip router isis 2

isis authen mode text level-2

isis circuit-type level-2

isis tag 2

int et1/0

ip router isis 2

isis authen mode text level-1

isis circuit-type level-1

isis tag 2

R3

router isis 3

net 49.0001.0010.0003.0303.00

area-password C1sc0!

int et0/0

ip router isis 3

isis authen mode text level-1

isis circuit-type level-1

isis tag 3

int et1/0

ip router isis 3

isis authen mode text level-2

isis circuit-type level-2

isis tag 3

R1 Verification: -

R1

Config t

Ipv6 unicast-routing

Router isis 1

Metric-style wide

Address-family ipv6 unicast

Multi-topology

Int loop0

Ip router isis 1

Ipv6 router isis 1

Isis tag 1

Int et0/0

Ipv6 router isis 1

Int et1/0

Ipv6 router isis 1

R2

Config t

Ipv6 unicast-routing

Router isis 2

Metric-style wide

Address-family ipv6 unicast

Multi-topology

Int loop0

Ip router isis 2

Ipv6 router isis 2

Isis tag 2

Int et0/0

Ipv6 router isis 2

Int et1/0

Ipv6 router isis 2

R3

Config t

Ipv6 unicast-routing

Router isis 3

Metric-style wide

Address-family ipv6 unicast

Multi-topology

Int loop0

Ip router isis 3

Ipv6 router isis 3

Isis tag 3

Int et0/0

Ipv6 router isis 3

Int et1/0

Ipv6 router isis 3

R1 Ipv6 Verification: -

L

R1

Copy run start

R2

Copy run start

R3

Copy run start

The correct configuration for enabling BGP FlowSpec client function and installation of policies on all local interfaces is flowspec address-family ipv4 install interface-all local. This command configures the router to accept FlowSpec policies from a BGP peer and apply them to all local interfaces. The flowspec keyword enables the BGP FlowSpec client function, address-family ipv4 specifies the address family, and install interface-all local ensures that the policies are installed on all local interfaces. References := Implementing and Operating Cisco Service Provider Network Core Technologies course.

In the context of OSPF multiarea implementation, adjacency issues can arise due to network type mismatches or area boundary discrepancies. The command “ip ospf network point-to-point” is used on interface G0/1 to specify the OSPF network type as point-to-point. This configuration facilitates OSPF neighbor establishment over a direct connection between two routers, eliminating the need for a designated router (DR) or backup designated router (BDR), and resolving adjacency issues in the new area. References: Implementing and Operating Cisco Service Provider Network Core Technologies source documents or study guide

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ iproute_ospf/configuration/xe-16/iro-xe-16-book/iro-multi-area-adj-xe.html

In the given architecture, if each area is running its own Interior Gateway Protocol (IGP), Border Gateway Protocol (BGP) must be used to provide an end-to-end Multiprotocol Label Switching (MPLS) Label Switched Path (LSP). This ensures that data packets can traverse through the different IGP areas seamlessly, maintaining connectivity across the entire network.

The configuration snippet shows that MPLS and LDP are configured globally but not enabled on an interface. The commands include “mpls label protocol ldp,” “mpls ldp router-id loopback 0,” and “mpls ip,” which are necessary for global settings. However, to establish LDP neighbors and exchange labels, LDP must be enabled on the specific interface where it’s needed.

References:

• Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR)
• Cisco SPCOR Training resources available on the Cisco Learning Network Store.

 In this scenario, BGP is used in the core of the service provider network, while OSPF serves as the PE-CE routing protocol. To ensure communication between CE1 and CE2, which are located in different geographical locations, it’s essential for PE1 and PE2 to share routes. This can be achieved by configuring both PEs to mutually redistribute BGP and OSPF routes within the VRF dedicated for that customer, ensuring seamless communication between both customer endpoints. References: Implementing and Operating Cisco Service Provider Network Core Technologies

The ttl-security hops 2 command sets the accepted Time to Live (TTL) value for BGP packets received from a neighbor. It is used to protect against BGP session hijacking by ensuring that BGP packets come from an expected number of router hops away. In this case, the command specifies that BGP packets from neighbor 2.2.2.2 must have a TTL of at least 253, which means they can only be 1 hop away (255 - 2 = 253) to be accepted.

References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) training material1.

The available PHY modes to implement an IOS XR Gigabit Ethernet interface are MAN (Metropolitan Area Network) and WAN (Wide Area Network). References:

• Cisco IOS XR Software Configuration Guide
• Cisco ASR 9000 Series Aggregation Services Routers Interface and Hardware Component Configuration Guide
• Hr40wan - 10 Gigabit Ethernet WAN PHY Controller Commands on Cisco IOS XR
• 10-Gigabit Ethernet WAN PHY Controller Commands 

RSVP tear messages are used to clear the PATH or RESERVATION states on a router instantaneously, which enables the reuse of resources on the router for other requests. This is essential in MPLS Traffic Engineering where efficient resource management is crucial for maintaining network performance and stability.

References: The explanation is based on the information provided in the Cisco Press article on MPLS TE Theory

• https://www.cisco.com/c/en/us/support/docs/mpls-vpns/multiprotocol-label-switching-mpls/23986-mpls-vpns-config-example.html
• https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/mp_l3_vpns/configuration/15-mt/mp-l3-vpns-15-mt-book/mp-bgp-mpls-vpns.html

The task requires the use of BGP’s well-known discretionary attribute to select the preferred path, excluding FTP prefixes from this selection process. Option B is correct because it applies a route map to incoming routes from a specific neighbor, which can be used to set attributes like local preference or AS path, or filter routes based on prefix lists or access lists.

The configuration snippet shows a route map named “ciscotest” that sets the local preference to 200 for routes matching IP address 1 (presumably defined elsewhere in an access list or prefix list). Local preference is a well-known discretionary attribute in BGP that influences path selection within an autonomous system; higher values are preferred.

References := Cisco - Implementing and Operating Cisco Service Provider Network Core Technologies

 Both Chef and Puppet are configuration management platforms that aim to configure and manage servers and other IT infrastructure. They operate in the same infrastructure management space and share several similarities:

• Use a master-client architecture: Chef functions with a master-client architecture, where the server runs on the master machine, and the client runs as an agent on every client machine. Similarly, Puppet follows a similar setup.
• Manage devices or nodes to be configured: Both Chef and Puppet manage the configuration of devices or nodes within an infrastructure.
• Leverage a pull model: Both tools use a pull model, where the configuration is pulled from a central server to the managed nodes.

To redirect traffic from ASN 64501 to 10.0.0.0/8 via the primary link North_A instead of the slow backup link North_B, setting a higher local preference between North_A and South_A is required. Local preference is a BGP attribute that helps in selecting the exit point from an AS (Autonomous System). By increasing local preference for routes received on North_A, traffic will be directed through this path as it becomes more preferred. References := Cisco Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR)