350-501 Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) Questions and Answers

During the traceback phase of the six-phase approach to service provider security, the action that occurs is tracing the attack flows from the attacked sections of the network toward the network edges. This phase entails identifying the source of the attack by analyzing the path that the attack traffic has taken through the network.

• 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 Cisco MPLS TE forwarding adjacency feature allows a TE tunnel to be advertised into the IGP, effectively making the tunnel appear as a network link in the IGP topology. This integration helps in the optimal utilization of the TE tunnel by other routers for IP routing purposes.

The IPv4 address family configuration under neighbor configuration-mode must be removed. The exhibit shows the configuration of a BGP neighborship between an ASBR and a directly connected BGP speaker. The ASBR is running Cisco IOS XR. The neighbor is configured with the IPv4 address family, which is not supported on Cisco IOS XR. To establish the BGP neighborship, the IPv4 address family configuration must be removed.

https://www.cisco.com/c/en/us/td/docs/routers/xr12000/software/xr12k_r41/routing/configuration/guide/routing_cg41xr12k_chapter1.html

 DWDM, or Dense Wavelength Division Multiplexing, uses different wavelengths of light to combine multiple optical signals. This method allows for the transmission of various data streams simultaneously over a single optical fiber. By using closely spaced wavelengths, DWDM can fit more channels onto a single fiber, significantly increasing the capacity and efficiency of fiber-optic networks.

References: The explanation is based on the information available from the web search results on DWDM, which aligns with the principles outlined in the Cisco Service Provider source book. 

1: PIM-DM 2:IGMP 3:PIM-SM 3:shared tree 4:source tree

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.

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.

 YAML’s readability and straightforward syntax make it an ideal choice for expressing infrastructure as code, which is a core principle in both Ansible and SaltStack for automating and managing IT infrastructure.

References: For more detailed information, please refer to the official documentation for Ansible and SaltStack, as well as the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials.

 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.

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

 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

Cisco IOS XE Software is an open and flexible operating system optimized for a variety of network infrastructures. One of its key enhancements over Cisco IOS Software is the support for symmetric multiprocessing (SMP). This allows the operating system to efficiently utilize multiple CPU cores, improving performance and scalability for network services.

References: The enhancement details are derived from the Cisco IOS XE Software overview, which highlights its capabilities and benefits over the traditional Cisco IOS Software.

Option B is the correct answer because it meets all the given requirements. The configuration “snmp-server community comaccess ro 10” allows read-only access for all objects to members of Access-List 10 that use the comaccess community string. The “snmp-server host ABC.com informs version 2c public” command ensures SNMP authentication failure traps are sent to SNMPv2c and then to the host using SNMPv2c with the public community string.

The configuration snippet indicates a BGP setup where the neighbor 192.168.1.2 is defined, but not activated for the IPv4 address family. To complete the configuration and allow the exchange of IPv4 routes, the neighbor must be activated under the IPv4 address family. This is done by adding the command address-family ipv4 unicast followed by neighbor 192.168.1.2 activate in the BGP configuration mode.

References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR v1.0); Cisco official documentation on BGP Configuration.

 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

R1

Router bgp 65515

No bgp default ipv4-unicast

Neig 2.2.2.2 remote-as 65516

Nei 2.2.2.2 update-soc loopback0

Nei 2.2.2.2 ebgp-multihop 2

Neig 2.2.2.2 pass C1sc0!

Nei 2000:cc13:cc13:2::1 remote-as 65516

Nei 2000:cc13:cc13:2::1 update-so loopback0

Nei 2000:cc13:cc13:2::1 pass C1sc0!

Nei 2000:cc13:cc13:2::1 ebgp-multihop 2

Address-family ipv4

Neig 2.2.2.2 activate

Address-family ipv6

Nei 2000:cc13:cc13:2::1 activate

Ip route 2.2.2.2 255.255.255.255 192.168.1.2

Ipv6 route 2000:cc13:cc13:2::1/128 2000:cc13:cc13:cc13::2

R2

Router bgp 65516

No bgp default ipv4-unicast

Neig 1.1.1.1 remote-as 65515

Nei 1.1.1.1 update-soc loopback0

Nei 1.1.1.1 pass C1sc0!

Nei 1.1.1.1 ebgp-multihop 2

Nei 2000:cc13:cc13:1::1 remote-as 65515

Nei 2000:cc13:cc13:1::1 update-so loopback0

Nei 2000:cc13:cc13:1::1 pass C1sc0!

Nei 2000:cc13:cc13:1::1 ebgp-multihop 2

Address-family ipv4

Neig 1.1.1.1 activate

Address-family ipv6

Nei 2000:cc13:cc13:1::1 activate

Ip route 1.1.1.1 255.255.255.255 192.168.1.1

Ipv6 route 2000:cc13:cc13:1::1/128 2000:cc13:cc13:cc13::1

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

In ISIS, routers can form neighbor relationships even with different system IDs, provided they are configured to be in the same area and the authentication between them is correctly set up.

References: For the most accurate answer, please consult the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials and the official Cisco documentation on ISIS configuration.

 In OSPF, for two routers to establish communication, they must have the same key ID and key value on their interfaces. This ensures secure communication between the OSPF peers. The key ID and value are part of the OSPF authentication mechanism that helps in validating the identity of OSPF peers before exchanging routing information. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Cisco SPCOR Training & Certification

In IS-IS, to advertise only the network prefixes associated with passive interfaces, the command advertise passive-only under the address family configuration mode is used. This ensures that only the prefixes of passive interfaces are advertised to other IS-IS routers in the network. The passive interface command is used to prevent IS-IS from forming adjacencies over that interface, while still allowing the network prefix of the interface to be included in the IS-IS link-state database.

References: For a comprehensive understanding, refer to the “Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR)” source book and study guide

R1

R2

 To establish MPLS LDP sessions between two routers, both routers must be configured to support MPLS on the interfaces that connect them. The configuration shown for R2 includes enabling MPLS label protocol LDP and configuring interfaces Ethernet1/0 and Ethernet1/1. However, to complete the MPLS LDP session setup, R2 also needs to have MPLS enabled on the interface toward R1. This is done by entering the interface configuration mode for the relevant interface and using the mpls ip command. This command enables MPLS forwarding for IP packets on the interface, which is necessary for LDP to advertise and map labels to the IP routes.

References := The answer is based on the concepts covered in the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course,

When OSPF routers establish adjacency, they must agree on the MTU size on the connecting interface. If the MTUs do not match, the routers will not form an OSPF adjacency, and the link between them will not come up. Therefore, configuring the MTUs on the interfaces to match is essential for the OSPF network to function correctly.

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

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

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 this scenario, E-LINE pseudowires are suitable because they create a point-to-point Ethernet connection between the two sites. E-LINE pseudowires are commonly used for point-to-point Ethernet services.
• References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) v1.0

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

 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

 In OSPF, for two routers to establish communication, they must have the same key ID and key value on their interfaces. This ensures secure communication between the OSPF peers. The key ID and value are part of the OSPF authentication mechanism that helps in validating the identity of OSPF peers before exchanging routing information. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Cisco SPCOR Training & Certification

 The local-as keyword is used in BGP configurations to change the local AS number that is used in the BGP OPEN message when establishing a BGP session with a specific neighbor. In this case, even though the router is configured with AS 65000, it will use AS 65112 when establishing a connection with neighbor 192.168.1.2 due to the local-as keyword configuration. References := Cisco

https://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13761-39.html

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 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

• NetFlow provides traceback information by analyzing network traffic. To configure NetFlow for traceback, you need to set up a classification ACL (Access Control List) to identify which type of traffic will be analyzed. This allows NetFlow to focus on specific traffic flows and report relevant information. The classification ACL can be based on various criteria such as source/destination IP addresses, port numbers, or protocols. By defining the classification ACL, you ensure that only the relevant traffic is considered for NetFlow analysis.
• References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) v1.0

YANG (Yet Another Next Generation) is a data modeling language used to model configuration and state data of a network. It is used to define the data structure of configuration files and is widely used for network configuration and management. YANG uses containers to categorize related nodes, allowing for a hierarchical organization of the data. Types can be associated with each leaf, but they are not required. Spines are not used in YANG, and it is not a distributed model of nodes.

 To implement a PIM-SSM (Protocol Independent Multicast - Source Specific Multicast) configuration for streaming live traffic across different domains, the network operator must ensure that IGMPv3 (Internet Group Management Protocol version 3) is enabled on R1. IGMPv3 is required for SSM because it allows the receiver to specify the source IP address of the desired traffic, which is a key feature of SSM. The operator would configure IGMPv3 on the interfaces that connect to the users who will be accessing the multicast stream. Additionally, PIM-SSM must be enabled on the router, and the multicast sources and groups must be properly defined.

References: The explanation is based on the concepts outlined in the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course

• In Cisco Unified MPLS, BGP (Border Gateway Protocol) is used to transport labels along with network layer reachability information. RFC 3107 defines BGP/MPLS IP Virtual Private Networks (VPNs) and allows BGP to carry MPLS labels, enhancing scalability and flexibility in MPLS networks.

References

1: Cisco. “Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR).” Link

https://community.cisco.com/t5/mpls/cisco-xr-rpl-destination-vs-destination-prefix/td-p/4587693

The Internet gateway router being connected as a PE router to the MPLS backbone is a design attribute that can be used to provide Internet access to a major customer through a separate dedicated VPN. This setup allows for efficient routing and separation of traffic, ensuring security and performance.

 In a gRPC dial-in configuration, the encoding is specified by the client initiating the connection. This setup allows for connection multiplexing, which means multiple gRPC calls can be made concurrently over a single connection, improving efficiency. Two-way streaming is also facilitated, allowing both the client and server to send a sequence of messages to each other, providing a full-duplex communication channel.

The issue with establishing an IS-IS adjacency between the two routers stems from a mismatch in the configuration of their interfaces. Router R2’s interface is set to point-to-point, while the peer router interface is set to multipoint. For IS-IS adjacencies to form, both interfaces must be configured with the same network type. The discrepancy in the network types is preventing the adjacency from being established. To resolve this, the network operator must ensure that both interfaces are either configured as point-to-point or as multipoint. References := Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR)

 A Multi-Layer control plane, like Cisco’s nLight technology, provides an integrated approach that allows for the automatic provisioning, monitoring, and management of traffic across different network layers, from Layer 0 (optical) to Layer 3 (IP). This integration increases network agility and flexibility while improving network utilization, leading to significant cost savings and more efficient network resiliency solutions2.

References: The Economics of Cisco’s nLight Multilayer Control Plane Architecture2.

In this scenario, gRPC dial-out mode is being used for telemetry. The receiver with IP address 192.168.1.1 will be assigned one of the subscriptions and will manage the ASR. To configure this, the router needs to use the protocol tcp command. This ensures that telemetry data is streamed out over a TCP connection to the specified receiver. Other options (A, B, and D) are not relevant for this specific use case.

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 OSPF neighbor relationship is not establishing due to a mismatch in MTU (Maximum Transmission Unit) settings on the interfaces of PE-A and PE-B routers. On PE-A, there is no MTU configuration under the interface FastEthernet0/0, which means it is using the default MTU setting. However, on PE-B, the MTU is explicitly set to 1400 bytes with “ip mtu 1400” command under interface FastEthernet0/0. OSPF requires that both ends of a point-to-point link have matching MTU sizes to form a neighbor relationship; otherwise, OSPF adjacency will not be established.

References:

• Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Cisco SPCOR Resources

The absence of routes learned by PE4 from PE5 in other PE routers’ routing tables is likely due to missing route target configurations. Route targets are crucial for importing and exporting VPN routes between VRFs in MPLS Layer 3 VPNs.

• Option D is correct because advertising the route targets for PE5 to the other PEs will allow them to import routes from PE5 into their respective VRFs, facilitating communication across the Layer 3 VPN.

References :=

• Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) source book and study guide.

TI-LFA, or Topology Independent Loop-Free Alternate, is a fast-reroute mechanism that provides protection against link or node failures in a network. It guarantees a loop-free alternate path for all areas configured in OSPF, ensuring traffic can be quickly rerouted in case of a failure. This characteristic is crucial for maintaining network stability and avoiding traffic loops, which can lead to packet loss and network congestion.

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

To configure multi-topology IS-IS for IPv6, the router must be configured with the ipv6 router isis command under the interface configuration mode. This command enables IS-IS for IPv6 on the interface. The ipv6 router isis command is used to enable IS-IS for IPv6 on an interface. The multi-topology keyword specifies that the interface will participate in multiple topologies. The level-1 and level-2 keywords specify the IS-IS levels for which the interface will participate. In this case, we want the interface to participate in both Level 1 and Level 2 topologies, so we use both keywords. 

OSPF adjacency is established when two OSPF routers have matching interface parameters. This includes the OSPF router ID, network address, area ID, and other OSPF-specific configurations such as MTU size and network type. For example, the configuration commands provided in the image description suggest setting the OSPF router ID, network address with a wildcard mask, and specifying the OSPF area. Additionally, the interface is set to a point-to-point network type with a specific MTU size, which is important for OSPF adjacency as mismatched MTU sizes can prevent OSPF neighbors from forming an adjacency.

References: For a comprehensive understanding, refer to the “Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR)” official Cisco documentation and study guide,

 In BGP, the Local Preference attribute is used to influence the exit point from an AS (Autonomous System). A higher local preference value is preferred, and all routes received inherit the local preference value of the route that is installed in the IP routing table. So, configuring a higher local preference outbound will make specific BGP speakers as preferred exit points for customer AS. References := Cisco

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

IntServ (Integrated Services) is a model that allows hosts to report their QoS (Quality of Service) needs to the network. In this model, applications inform the network about their bandwidth requirements and traffic characteristics, enabling the network to reserve resources and provide the requested QoS. References := Implementing and Operating Cisco Service Provider Network Core Technologies

 The issue likely lies in the customer platforms’ default policy, which restricts E-BGP route exchange. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials.

https://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k-r6-2/routing/configuration/guide/b-routing-cg-asr9000-62x/b-routing-cg-asr9000-62x_chapter_010.html

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.

When implementing LDP NSF on your network, enabling NSF for the link-state routing protocol in use on the network is essential to ensure continuous forwarding of packets during a failure scenario. Additionally, enabling NSF for BGP ensures that BGP sessions are not dropped during a switchover, maintaining network stability and uptime.

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.

For encrypted authentication on Router 1, the correct action is to configure an SNMP user with an authentication password and associate it with a group. Option B includes the use of MD5 authentication, which provides the required security for message confidentiality.

 The number “2” in the SNMP server configuration “snmp-server community ciscotest ro 2” refers to the numeric name of the Access Control List (ACL) that contains the list of SNMP managers with access to the agent. In this context, “ro” stands for read-only access, meaning that SNMP managers can only read but not modify data on the device. The ACL identified by number “2” specifies which SNMP managers are authorized to access SNMP data on this device using the community string “ciscotest”.

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

 The JSON script in the exhibit configures BGP with a neighbor at IP address 192.168.1.2 that resides in AS (Autonomous System) 65514. In the script,  specifies the neighbor’s IP address, and  indicates the AS number of the neighbor.

References: For more information, you can refer to the “Implementing and Operating Cisco Service Provider Network Core Technologies” training, which covers topics such as configuring, verifying, troubleshooting, and optimizing Service Provider IP network infrastructures, including BGP configurations

The configuration in Option C correctly sets up the interfaces for VLAN tag translation. On interface GigabitEthernet2, the command rewrite ingress tag translate 1-to-1 dot1q 21 changes the incoming VLAN tag from 12 to 21. Conversely, on interface GigabitEthernet3, the command rewrite egress tag translate 1-to-1 dot1q 12 changes the outgoing VLAN tag from 21 to 12. This setup ensures that traffic flowing from R1 to R2 and vice versa has the correct VLAN tags as required.

References: This explanation is based on the concepts outlined in the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR v1.0) course

The issue is occurring in OSPF stub area 100 where the Ethernet link is down between routers RX and RY due to a cut fiber, leading to dropped traffic from CE site A to the hub site. Changing the OSPF area 100 type to stub on RZ can resolve these issues. In a stub area, OSPF routers use a default route to forward traffic to destinations outside the area, reducing the size of their routing tables. This would allow traffic from CE site A to be routed through RZ when the direct link between RX and RY is down.

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

• Option B: Internet routing through global routing on a PE router means that the PE router performs global routing for internet traffic. This allows the PE router to handle both L3VPN traffic and internet traffic.
• Option D: Leaking internet routes from the global table into the L3VPN VRF allows the L3VPN customers to access the internet via the same MPLS backbone. The PE router imports internet routes into the L3VPN VRF, enabling internet access for VPN customers.

The configuration shown indicates that Router 1 is set up with a route-map named “ddos” that matches traffic tagged with “tag 1”. The traffic matching this tag is then set to have a next-hop IP of 192.0.2.1 and a local preference of 150. The community is also set to “no export”, which means this route will not be advertised to external BGP peers. Since there’s no explicit deny statement in the configuration, only traffic with tag 1 and local preference of 150 will be dropped by Router 1 as per the BGP routing policy. References: Implementing and Operating Cisco Service Provider Network Core Technologies course materials. 

 In the given configuration, “tacacs-server host 192.168.1.2 single-connection” indicates that Router 1 will maintain a single connection to the TACACS+ server at IP address 192.168.1.2 for multiple authorization requests instead of opening a new connection for each request. This can be efficient in scenarios where there are frequent authorization requests as it reduces the overhead associated with establishing a new TCP connection each time.

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

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)

 The router RA is configured with the command “ip pim ssm default”. This configuration enables Source-Specific Multicast (SSM) for the default range of 232.0.0.0/8, which is the IPv4 multicast address space reserved for SSM by IANA (Internet Assigned Numbers Authority). In SSM, data traffic is delivered to a specific group of subscribers identified by the combination of both source and multicast addresses, enhancing efficiency and security. References: Implementing and Operating Cisco Service Provider Network Core Technologies

 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 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

 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.

 When implementing Nonstop Routing (NSR) High Availability on an MPLS Provider Edge (PE) router, it’s important to consider that NSR generally consumes more memory and CPU resources than Nonstop Forwarding (NSF) because it needs to maintain a stateful switchover capability. Additionally, NSR requires routing protocol extensions to ensure that the state information is correctly synchronized between the active and standby routers, allowing for seamless failover without session loss. This ensures continuous packet forwarding even during a switchover event.

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.

 The control plane protocol used between Cisco SD-WAN routers and vSmart controllers is the Overlay Management Protocol (OMP). OMP is a proprietary protocol of Cisco SD-WAN that facilitates the exchange of routing, policy, and management information across the network. It operates within the secure environment provided by the Datagram Transport Layer Security (DTLS) or Transport Layer Security (TLS) control connection, ensuring that the communication between the routers and controllers is encrypted and authenticated1.

References := Cisco 300-415: Cisco SD-WAN vSmart-WAN Edge Router Control Plane Protocol

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

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

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.

 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

 Enabling MPLS LDP IGP Synchronization ensures that the IGP advertises a route only if there is a corresponding label binding from LDP. This synchronization helps prevent blackholing traffic when there is a direct link failure in the network. When the B-C link failed, the IGP could find an alternate path via routers E and F, but without LDP synchronization, the labels for MPLS were not available on this new path, leading to traffic loss. By enabling LDP IGP Synchronization, routers will only use paths for which a complete set of labels exists, ensuring label forwarding occurs on the alternate path.

References: The information provided is based on the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials, which cover the configuration, verification, troubleshooting, and optimization of Service Provider IP network infrastructures, including MPLS LDP IGP Synchronization

 The REST API command shown in the exhibit is a POST request to a specific URL, indicating that it is used to submit data to be processed to a specified resource. In this case, the resource is an XML file named “Descriptions.xml”. POST requests are used when submitting data to be processed by the resource identified by the URI. The nature of the process conducted on the submitted data depends on that particular URI. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - REST API section.

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

 Both options provide a default route pointing to CE-1, allowing CE-2 to access the internet. The specific choice would depend on additional context or requirements not provided in the question.

References:

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

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.

 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 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

The configuration shown is for the head-end router of a Cisco MPLS TE tunnel with segment routing. This setup involves commands related to segment routing and MPLS traffic engineering tunnels, such as “mpls traffic-eng tunnels”, “segment-routing mpls”, and “segment-routing prefix-sid-map advertise-local”. These commands configure the head-end router to effectively create and manage TE tunnels using segment routing. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Cisco SPCOR Training & Certification.

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

• Option A corresponds to the desired configuration. It uses an access-list to permit IGMP joins for the specific multicast group 239.10.10.10 from the source 172.20.20.3.
• Options B, C, and D do not match the desired configuration. They either allow all IGMP traffic or do not specify the correct source and group addresses.

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

When implementing a prefix list, it is a best practice to use nonsequential sequence numbers. This allows for the insertion of additional entries at a later time without the need to renumber the entire list, providing flexibility in managing the prefix list.

References: Best Practices for Implementing a Prefix List - exam-answer.com4.

Network Services Orchestrator (NSO) uses the YANG (Yet Another Next Generation) modeling language to provide a standardized way to automate network devices. YANG provides a powerful schema to model configuration and state data for network elements, which NSO leverages for service automation and orchestration.

References: Cisco Crosswork Network Services Orchestrator (NSO) - Cisco2.

 When interface Gi0/0/0/2 is shut down for maintenance, the other interfaces’ states are affected based on their current configurations and roles. In this case, Gi0/0/0/0 becomes active because it is next in line to take over the traffic load, ensuring that network service remains uninterrupted. Gi0/0/0/1 remains standby as it was before the shutdown of Gi0/0/0/2.

References: The explanation can be inferred from understanding Cisco’s technology and protocols related to interface states and bundle ether configurations,

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

The configuration creates a class map named WEB which is used to match HTTP traffic. This class map can then be referenced in a policy map to define specific actions for traffic that matches the criteria, such as applying QoS policies or traffic shaping.

References: This concept is covered in the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course, where class maps and policy maps are discussed in the context of traffic classification and policy enforcement.

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

 In OSPF, the election of the designated router (DR) and backup designated router (BDR) is based on the OSPF network type. The network types include:

• Broadcast: This is the default network type for Ethernet interfaces. In a broadcast network, OSPF elects a DR and BDR. All other routers become DROTHERs. To prevent the election of a DR/BDR, you can configure the interface as non-broadcast (NBMA) using the ip ospf network non-broadcast command.
• Point-to-Point: This network type is used for point-to-point links (e.g., serial links). There is no DR/BDR election in point-to-point networks.
• Point-to-Multipoint: This network type is used for point-to-multipoint links (e.g., Frame Relay). There is no DR/BDR election in point-to-multipoint networks.
• Point-to-Multipoint Non-Broadcast: Similar to point-to-multipoint, but explicitly configured as non-broadcast. There is no DR/BDR election in point-to-multipoint non-broadcast networks.
• Loopback: Loopback interfaces are always treated as point-to-point.
• Virtual-Link: Used for OSPF virtual links.
• Sham-Link: Used for OSPF sham links.
• Demand Circuit: Used for demand circuits (e.g., ISDN).
• Non-Broadcast: Explicitly configured as non-broadcast. There is no DR/BDR election in non-broadcast networks.

References:

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

Flexible NetFlow improves on traditional NetFlow by providing more flexibility and efficiency in collecting and analyzing network flow data. In this specific configuration, the “mode random one-out-of-100” command is used, which means that only one out of every 100 packets is sampled. This leads to reduced CPU and memory utilization (Option A) because fewer packets are being processed. Additionally, because fewer packets are being analyzed (only one out of every 100), the number of packets to be analyzed is significantly reduced (Option D), leading to further efficiencies.

References :=

• Implementing and Operating Cisco Service Provider Network Core Technologies
• On-Demand E-Learning

The OSPF adjacency issue between R1 and R2 is likely due to mismatched OSPF network types or hello/dead interval settings. The command ip ospf network point-to-point is used on point-to-point network types, which do not require matching hello/dead intervals, thus allowing OSPF adjacency to form even if these intervals are mismatched on the two routers. References: = Implementing and Operating Cisco Service Provider Network Core Technologies course materials. (

 A Virtual Network Function (VNF) role refers to a network function that is executed in software and can be deployed on a Network Functions Virtualization Infrastructure (NFVI). A firewall serves as a VNF role because it performs network functions, such as filtering traffic and security management, in software form rather than as a physical device.

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

The correct configuration for MPLS LDP synchronization with OSPF process 1 on router R1 is to use the command mpls ldp igp sync holddown 60 under the OSPF process configuration. This ensures that the MPLS LDP synchronization is enabled and held for 60 seconds with OSPF process 1, which helps prevent black holes in MPLS networks during the convergence process by ensuring that routes are not advertised until LDP is fully operational and labels have been exchanged between adjacent routers.

References:

• Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Cisco SPCOR
• Additional resources on Cisco’s Service Provider training: Cisco Service Provider Training