350-501 Sample Questions Answers

In the context of OSPF multiarea implementation, adjacency issues can often be resolved by specifying the type of network on the interface. In this case, option B “ip ospf network point-to-point” is appropriate as it helps in forming OSPF adjacency over point-to-point links by allowing OSPF to use a simpler neighbor discovery process, which can resolve adjacency issues. References := Implementing and Operating Cisco Service Provider Network Core Technologies

 The error message “%CLNS-4-AUTH_FAIL: ISIS: LAN LIIH authentication failed” indicates that there is an authentication failure in the IS-IS routing protocol between routers R1 and R2. In the exhibit, it can be observed that R2 has a state of “UP” for its IS-IS neighbor relationship, while R1 is in “INIT” state. This discrepancy in states indicates an issue with the establishment of the neighbor relationship, which can be attributed to an authentication failure at both Level 1 and Level 2 PDUs as indicated by option B.

References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) official guide or documentation available on Cisco’s official website.

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

Packet loops can occur during the configuration of BIDIR-PIM if not all parts of your network support this protocol or are configured correctly for it. If some routers or switches in your network don’t understand or aren’t configured for BIDIR-PIM, they can inadvertently forward packets back into parts of the network they were already in, creating a loop. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Multicast section.

In the Pipe model of MPLS QoS, the MPLS EXP bits are set by the Customer Edge (CE) device. This model allows the CE to mark the packets, and these markings are retained throughout the MPLS network until they reach the egress Provider Edge (PE) router. The PE router does not alter the MPLS EXP value, ensuring that the QoS policy applied by the customer is preserved end-to-end.

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

 In BGP, the weight attribute is the first criterion used to determine the best path. It is a Cisco-specific attribute and is not propagated in BGP updates. Weight is a numeric value, and the path with the highest weight is preferred. If weights are the same, BGP will then consider the local preference, AS path length, origin type, and other attributes in sequence.

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

The term ‘ImpNull’ in the CLI output indicates that Label 0, also known as the “Implicit Null” label, is used for the prefix displayed. This label instructs the penultimate router in an MPLS network to pop the label before forwarding the packet to the ultimate hop, which is the egress router. Therefore, Label 0 will not be part of the MPLS label stack for packets destined for 192.168.10.10 (Option A). This process is known as Penultimate Hop Popping (PHP) and is used to optimize the forwarding process by reducing one level of lookup at the egress router (Option D).

References: For more detailed information, please refer to the MPLS section in the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials.

The ISIS topology exhibit indicates that all four routers are configured as Level 1-2 routers, which means they can operate in both Level 1 and Level 2 IS-IS areas. This is evident from the net addresses that show a mix of area addresses, allowing for intra-area (Level 1) and inter-area (Level 2) routing. Additionally, R1 and R2 are Level 2 neighbors because they have different area addresses, allowing them to form Level 2 adjacencies and route between different areas.

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

 The number 2 in the configuration “snmp-server community ciscotest ro 2” is significant because it 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, meaning that SNMP managers listed in ACL 2 can only read data from the SNMP agent but cannot modify it. The ACL defines which IP addresses are allowed to access SNMP data. References: Implementing and Operating Cisco Service Provider Network Core Technologies source documents or study guide

 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

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 MPLS Layer 3 VPNs, shared services such as Internet access can be provided through the use of a shared services VRF (Virtual Routing and Forwarding). The customer VRF uses route targets to import routes from the shared services VRF, which contains the routes to the Internet. This allows the customer sites to access the Internet without compromising the isolation of their private networks. References: The concept of shared services VRF and the use of route targets for importing and exporting routes are common practices in MPLS VPN implementations.

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.

MPLS TE FRR (Fast ReRoute) provides backup protection by creating a bypass LSP for each protected LSP at each point of local repair. This method allows for rapid switching to the backup path in case of a failure, minimizing traffic loss and disruption.

References :=

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

 Egress PE NAT via a single centralized router allows L3VPN customers to access the internet. The NAT operation maintains a table that includes a field to identify the inside VRF of a translation. This is crucial for distinguishing between different customer VPNs that may use overlapping IP address spaces. By having this field, the NAT process can correctly associate each internal IP with its respective VRF and outside global IP address1. References: Centralized egress to internet, Egress PE NAT single centralized router.

 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

Here is the solution:

Graphical user interface, text Description automatically generated

A SYN flood is a type of denial-of-service (DoS) attack where an attacker sends a large number of SYN requests to a target server, overwhelming its resources and preventing legitimate connections. The attacker does not complete the TCP handshake, leaving the server in a half-open state.

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.

Best – 50.50.50.2

2nd Best – 40.40.40.2

3rd Best – 20.20.20.2

44th Best – 30.30.30.2

The issue is that router R2 is not installing the network 172.16.33.1/32 in the routing table due to an incorrect access list configuration. The correct answer is option C, which will allow the network to be installed in the routing table by permitting addresses from 172.16.33.0 to 172.16.33.255 with a wildcard mask of 0.0.0.255.

The current access list on R2, “access-list 1 permit 172,16,32,0 0,0,0,255”, only permits addresses from the range of 172,16,32,0 to 172,16,32,255 due to its wildcard mask of “0,.0,.0,.255”. This does not include the address “172,.16,.33,.1”.

References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) study guide or course materials available on Cisco’s official website or authorized training partners.

• The BGPsec framework is designed to secure the AS path information in BGP updates. It uses digital signatures to validate the AS path and prevent unauthorized route manipulation. Here are the key points related to BGPsec:

• Securing AS Path:
• Private Keys and Router Key Pair:
• Expiration Time:

In summary, BGPsec enhances BGP security by securing the AS path using digital signatures and private keys. It does not rely on IPsec tunnels for security1.

References:

• Cisco. (2021). Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) v1.0. Cisco Learning Services.
• Cisco. (2021). Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) v1.1. Cisco Learning Network Store.
• Cisco. (2021). BGPsec Overview. Link

 The configuration sets up a telemetry subscription to collect and send data every 60 seconds, which is indicated by the sample-interval 60000 setting in the configuration. References: For more detailed information, please refer to the official Cisco documentation on Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) and the specific section on Telemetry Configuration.

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.

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 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. 

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.

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 Cisco IOS XR software, the keychain management for BGP is done in the routing configuration mode. This mode allows you to configure keychain parameters such as the key identifier, cryptographic algorithm, and other related settings. The keychain is essential for authentication and secure communication between BGP peers. By configuring the keychain in the routing context, you ensure that BGP sessions use the specified keys for authentication and integrity protection1.

References:

• Implementing Keychain Management - Cisco IOS XR Routing Configuration Guide
• BGP Configuration Guide for Cisco NCS 540 Series Routers, IOS XR Release 7.8.x - Master Key Tuple Configuration

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

The script is designed to leverage REST API calls for network configuration tasks. It uses the requests library in Python to send a PATCH request to the device with IP address 172.168.211.65. The script includes RFC 2617-based authentication, which is used for HTTP, indicating that it’s not using SSH for login. The payload of the REST API call specifies the configuration for the interface GigabitEthernet0/1 with the IP address 10.1.131.112/30. Therefore, the script is performing option B, configuring the interface via REST API calls.

References: The explanation is based on general knowledge of Python scripting for network automation and REST API interactions as typically covered in network automation sections of Cisco Service Provider courses and documentation. 

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

In NetFlow export statistics, the BGP next hop information is not included by default. To include the BGP next hop in the export statistics, specific keywords related to BGP next hop must be configured with the version 9 NetFlow entry. This configuration allows for the measurement of network traffic on a per-BGP next hop basis, which is essential for detailed traffic analysis and accounting1. References: Configuring NetFlow BGP Next Hop Support for Accounting and Analysis - Cisco Systems1.

To collect the required traffic statistics, the network engineer must configure the router to capture specific data points. The configurations in Option A and Option D align with these requirements. Option A involves configuring the router to collect IPv4 protocol, source address, destination address, application name, interface output, IPv4 source-prefix, IPv4 destination-prefix, counter bytes, flow direction, and transport tcp-flags. Option D involves setting the cache-period timer active to 20 seconds, which aligns with the CPU limit of processing samples that are a maximum of 20 seconds long.

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

 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 issue of no LDP neighbor existing for 1.1.1.1 between two directly connected routers could be due to R2 not receiving any hellos from R1. In the context of LDP (Label Distribution Protocol), hellos are used for the discovery of LDP peers. They are sent periodically on each interface that LDP is enabled on to discover and maintain LDP sessions with neighbors. If R2 is not seeing any hellos from R1, it means there’s a failure in the initial step of establishing an LDP session, hence no neighbor relationship is formed.

References: Implementing and Operating Cisco Service Provider Network Core Technologies source documents or study guide can provide more insights into the workings and troubleshooting steps for LDP protocol.

Remember that SSM is an extension of IP multicast where datagram traffic is forwarded only from explicitly joined multicast sources to receivers. It creates source-specific multicast distribution trees without shared trees.

References:

• Cisco PIM-SSM Configuration Example
• Cisco IP Multicast: PIM Configuration Guide

The configuration ip verify unicast source reachable-via any under interface gigabitethernet0/1 on Router 1 ensures that incoming packets have a source IP address that matches an entry in the FIB (Forwarding Information Base), indicating it’s reachable via a real interface. This helps mitigate attacks by dropping traffic with unreachable source addresses. References := Cisco

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

• 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

Cisco Network Services Orchestrator (NSO) acts as a bridge between application or service owners and infrastructure owners, allowing each team to operate in their native environment while still collaborating effectively together. It simplifies service delivery and management by bridging the gap between applications and network devices

https://www.cisco.com/c/en/us/products/collateral/cloud-systems-management/network-s ervices-orchestrator/datasheet-c78-734576.html

 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

R1

router ospf 10

redistribute static

int et0/0

ip ospf hello-interval 5

ip ospf dead-interval 10

ip ospf cost 15

ip ospf 10 area 0

copy run start

R2

router ospf 10

redistribute static

int et0/0

ip ospf hello-interval 5

ip ospf dead-interval 10

ip ospf cost 15

ip ospf 10 area 0

copy run start

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

To ensure that a router advertises only networks with a prefix mask length less than or equal to 21 to its BGP neighbor, the correct configuration is Option A. This involves applying a prefix list that permits updates for networks with the specified prefix length. The prefix list acts as a filter for outgoing route advertisements in BGP, ensuring that only routes that match the criteria are advertised to the neighbor.

Segment routing prefix segments are linked to a prefix SID that is globally unique within the segment routing domain. This means that each prefix SID identifies a specific prefix in the network and is unique across the entire segment routing-enabled domain, ensuring that the path to the prefix can be identified and used by any node within the domain1. References: Introduction to Segment Routing - Cisco Learning Network2, ASR9000/XR Introduction to Segment Routing - Cisco Community3, About Segment Routing - Cisco Content Hub

When choosing between SaltStack and Chef for network automation, it is important to consider that Chef is an agent-based tool written in Ruby, while SaltStack is a Python-based module tool. This fundamental difference in language and architecture can influence the decision based on the existing environment and the team’s expertise.

References :=

• Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials.
• Official Cisco documentation and training resources available on the Cisco Learning Network Store.

The weight parameter in BGP (Border Gateway Protocol) is a Cisco-specific attribute that is local to the router on which it is configured. It is used to prefer one path over another when multiple paths to the same destination are available. The weight is not advertised to other routers, making it a local parameter.

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

NetFlow version 9 can report additional information such as BGP Autonomous System (AS) information due to its template-based design, which allows for flexibility and support for a wider range of IP flow information, including IPv4 and IPv6 flow information, BGP routing information, and multicast flow data.

 The configuration in the exhibit shows that R1 is configured with “mpls ldp graceful-restart”, which enables LDP Graceful Restart on the router. This means that R1 can support a graceful restart operation on the peer, even if graceful restart is disabled on the peer. This feature allows LDP to recover from failures without affecting the forwarding plane, ensuring network stability and minimal packet loss during failovers.

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

TASK1:Run “sh run” command on both routers, check if there is any “router ospf” configured. If it’s configured, check if Loopback0 ip it’s being used as OSPF ID. If it’s, jump to TASK2. Otherwise run:R1

router ospf 10

router-id 10.1.1.1

R2

router ospf 10

router-id 10.2.2.2

TASK2:

R1 & R2

int lo0

ip ospf 10 area 0

ip ospf network point-to-point

!

int e0/0

ip ospf network point-to-point

ip ospf 10 area 0

ip ospf authentication message-digest

ip ospf message-digest-key 1 md5 C1sc0!

!

 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

To implement Bidirectional Forwarding Detection (BFD) in an IS-IS environment, the first task is to configure BFD in an interface configuration mode. This involves setting up BFD parameters on the interfaces where IS-IS is running to enable quick failure detection.

References: Implementing BFD in an IS-IS Environment - Exam-Answer3.

• : In the context of telemetry for data analytics, a destination (such as a collector or monitoring system) initiates a session to a router. This session allows the router to send telemetry data to the destination for analysis.
• References: Implementing and Operating Cisco Service Provider Network Core Technologies.

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

 To prevent an MPLS TE Label Switched Path (LSP) from using any overseas links, an operator would use the explicit path feature. This feature allows the operator to define a specific route for the LSP to follow, which can be configured to exclude paths that traverse overseas links.

https://www.cisco.com/c/en/us/support/docs/multiprotocol-label-switching-mpls/mpls/215215-segment-routing -overview-and-migration-g.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

 Router R1 is configured as a stub area with the “no-summary” option, which means it will not receive summary LSAs (Type 3) from the Area Border Router (ABR). It will only have Type 1 (Router LSAs) and Type 2 (Network LSAs) in its OSPF database for the area it belongs to. Router R2 is configured as an NSSA (Not So Stubby Area), which allows it to import AS external routes as Type-7 LSAs. These Type-7 LSAs can then be converted to Type-5 LSAs by the ABR when propagated into other areas. Therefore, R2 has Types 1, 2, and 7 LSAs in its OSPF database.

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 OSPF area types and LSA types.

 In IS-IS, Level 2 peers must have matching authentication settings to ensure security and integrity of the routing domain. The hello timer setting must also match to ensure that the peers can maintain a consistent adjacency state. Mismatched hello timers could lead to adjacency flaps or failure to form an adjacency.

References: The information is based on the IS-IS protocol’s use of TLVs (Type-Length-Value) which makes it highly extensible. As new features come in, they can be added to the protocol with TLVs. This includes authentication mechanisms and timer settings that ensure secure and stable adjacencies between Level 2 peers

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

 NSO, or Network Services Orchestrator, provides full lifecycle management of devices and services in a network. It is designed to automate the service lifecycle from design and creation through deployment and decommissioning, without the need for manual intervention. This includes configuration, activation, updating, and ultimately, removal of services.

References: The role of NSO is detailed in the Cisco Crosswork Network Services Orchestrator (NSO) documentation

• 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.

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.

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.

 The “show cef interface” command is used to display per-interface statistics about Unicast Reverse Path Forwarding (uRPF) drops and suppressed drops. uRPF is a feature that helps to mitigate problems caused by IP address spoofing, and the “show cef interface” command provides detailed information on the interfaces where uRPF is applied, including drop statistics.

 The Network Services Orchestrator (NSO) is designed to allow service providers to automate network operations efficiently. It provides a single, well-defined API that enables integration across various network environments. NSO’s capabilities include zero-touch telemetry, machine learning intuition, open APIs, and automated actions, which facilitate a simpler and more efficient network operation experience. This makes it an ideal choice for service providers looking to plan, optimize, and achieve closed-loop operations within their networks.

References := The information is based on the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) training and certification resources, which offer a deep dive into service provider technologies, including core architecture, services, networking, automation, quality of services, security, and network assurance123.

The configuration in Option C uses a route policy that checks if the MED is equal to 30 and then sets the local-preference to 70. This aligns with the requirement to prioritize routes with a MED of 30 by assigning them a higher local-preference value, which influences the BGP path selection process in favor of these routes.

References := The Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course provides insights into configuring route policies for BGP, which includes setting local-preference based on MED values

The failure to implement IS-IS multitopology can be attributed to the routing process not supporting extended metrics. Extended metrics are necessary for multitopology routing because they allow for the definition of multiple topologies within the same routing protocol, each with its own set of metrics and paths1.

References:

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

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.

 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 issue of Router 1 failing to establish an OSPF peering with Router 2, and the increase in CPU and memory usage can be attributed to a mismatch in MTU (Maximum Transmission Unit) sizes. In OSPF, for a successful adjacency to be formed, the MTU size on the interfaces that are trying to form this adjacency must match. In this case, changing the MTU to 1524 on Router 1 will make it compatible with Router 2, allowing OSPF peering to be established and customer traffic to pass through successfully.References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Cisco

 The MPLS LSP ping is the utility that must be used to locate MPLS faults. It is specifically designed to troubleshoot Multiprotocol Label Switching (MPLS) by sending a ping through the MPLS network to verify the path and identify any issues.

References: Cisco provides a guide on MPLS Troubleshooting

 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.

Diagram Description automatically generated

 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

 MPLS LDP (Label Distribution Protocol) is used for label distribution in MPLS networks. When making changes to the LDP configuration, it’s essential to ensure that the changes do not disrupt existing LDP sessions. In this scenario, the network administrator implemented MPLS LDP changes on the PE-A LSR (Label Switching Router) device, and the goal is to prevent any disruption to LDP peers.

The MPLS LDP Non-Stop Routing (NSR) feature allows LDP sessions to survive control-plane switchover events without interruption. When NSR is enabled, the LDP session state information is synchronized between the active and standby control planes. If the active control plane fails, the standby control plane takes over seamlessly, and LDP sessions continue without interruption.

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/msp/configuration/xe-3s/mp-ha-xe-3s-book/mp-nsr-ldp-supp.pdf

• 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. 

 In XML, a self-closing tag such as  indicates that the element does not contain any data, hence the data field is considered blank. This is a common way to represent empty elements in XML documents.

References: For further details, you can refer to XML-related sections in the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) materials, which explain the structure and usage of XML in network configurations.

 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.

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 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.

 ISP delegation to PCE servers involves assigning specific tasks or roles to different PCE servers within a network. Option A refers to adding a new PCE server with lower precedence than the primary PCE, which means introducing an additional server that has less priority in task execution compared to the existing primary one. Option B involves changing the precedence of any of the PCE servers, indicating a modification in their hierarchical order or priority for task execution. References := Cisco Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR)

 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

 OSPFv3 is designed to support both IPv4 and IPv6. The message “IPv6 routing not enabled” indicates that IPv6 has not been configured on the router, but this does not prevent OSPFv3 from running for IPv4. The OSPFv3 configuration for IPv4 will still function on the interface FastEthernet0/0 as intended.

To achieve this, router 2 should use a route map to filter the routes being redistributed from BGP into OSPF. Specifically, the route map should match the internal route from Lo 2 (which is the loopback interface on router 2) and allow only that route to be redistributed. The other options do not achieve this specific requirement. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) source book.

 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

The correct configuration for the BGP route policy named SUBNET, as per the second set of text in the image details, is to drop traffic if the destination is in BGP. Otherwise, the MED value should be set to 400 and community (4:400) should be added. This matches Option B, which specifies these exact actions. References := The information is based on the image details provided and aligns with common BGP route policy configurations typically found in Cisco’s service provider network core technologies documentation.

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.

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.

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.

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)

• 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://www.cisco.com/c/en/us/support/docs/quality-of-service-qos/qos-policing/19645-policevsshape.html