Free and Premium Cisco 350-501 Dumps Questions Answers

The network operator needs to provide connectivity between two IPv4 and IPv6 dual-stacked networks using specific assigned IPv6 space. NAT46 (Network Address Translation 46) is the appropriate technology for this scenario. It allows translation between IPv4 and IPv6 addresses, enabling communication between the dual-stack networks. NAT46 maps IPv6 addresses to IPv4 addresses and vice versa, facilitating seamless communication across different address families. References: Implementing and Operating Cisco Service Provider Network Core Technologies

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

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

The primary role of a BR (Border Relay) router in a 6rd (IPv6 Rapid Deployment) environment is to connect the CE (Customer Equipment) routers with the IPv6 network. The BR router de-encapsulates IPv6 packets that are encapsulated in IPv4 packets from the CE routers and forwards them to the IPv6 internet. This process is stateless and allows for high availability and load balancing by potentially having more than one BR router configured with the same IPv4 address (anycast), so CE routers are routed to the closest BR router12.

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

The command PE-A(config-pmap-c)#set dscp ef is used to apply DSCP marking to the traffic matched by the class-map. DSCP marking is a part of QoS policy to prioritize traffic. The ‘ef’ (Expedited Forwarding) value is commonly used for voice traffic to ensure it receives high priority and low delay through the network.

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.

 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.

 The TTL security mechanism is used to protect a router from receiving BGP sessions that are not originated from the expected peer. It drops incoming TCP segments whose TTL value is not equal to or greater than the expected minimum value, thus helping in preventing DoS attacks that could be initiated from an unauthorized source pretending to be a legitimate BGP peer. References := Implementing and Operating Cisco Service Provider Network Core Technologies

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

In an EVPN operation, the PE (Provider Edge) router determines and advertises Ethernet segment reachability by discovering remote ESIs (Ethernet Segment Identifiers) and determining their redundancy mode (all-active or single-active). This is crucial in multihoming scenarios where the PE needs to auto-discover remote PEs and the corresponding redundancy mode. In case of segment failures, PEs withdraw the routes used at this stage to trigger fast convergence by signaling a MAC mass withdrawal on remote PEs3.

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

 The issue is that the R2 Serial 1/0 interface is configured with an IP address, but the R1 Serial 1/0 interface is unnumbered. In OSPF, for two routers to form a neighbor relationship, they must be able to communicate on the same subnet. If one interface is unnumbered and the other has an IP address, they won’t be able to form a neighbor relationship, leading to OSPF prefixes missing from the routing table. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - OSPF Configuration Guide

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.

 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 difference between SNMP (Simple Network Management Protocol) and model-driven telemetry lies in their data delivery mechanisms. Telemetry allows for modeled network data to be pushed to network administrators on an as-needed basis, providing real-time insights into network performance and health. On the other hand, SNMP typically relies on polling mechanisms where network administrators request data at specific intervals. References: Implementing and Operating Cisco Service Provider Network Core Technologies source documents or study guide

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 script shown in the exhibit is a REST API call that adds a user with the last name ‘CiscoTest’ to the AAA database on the server located at the IP address 192.168.201.10. This is achieved through a POST request, which is typically used to create or update resources on a server. The script specifies the user details in JSON format, which is a common data format used for API calls.

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.

roducts/collateral/switches/nexus-9000-series-switches/guide-c07-734107.html

 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 A is used to implement URPF in loose mode on the GigabitEthernet0/1 interface.

Loose mode allows the router to check for any route back to the source, not necessarily the best route.

By enabling URPF, the router ensures that incoming packets have a valid return path in the routing table.

This helps prevent IP spoofing and limits malicious traffic on the network.

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 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.

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

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.

In the context of regular expressions, the caret (^) is used to indicate the start of a string. This is a fundamental concept in pattern matching using regular expressions, where ^ matches the position at the beginning of the string.

 The ttl-security hops  command sets the maximum number of hops that a BGP message can traverse. In this case, setting ttl-security hops 2 means that the router will accept BGP packets from a neighbor (2.2.2.2) only if the TTL is 253 or more. This is because the default TTL value is 255, and for each hop, the TTL is decremented by 1. Therefore, a packet from a directly connected neighbor would have a TTL of 254 when it reaches the PE router. If the packet has traversed one more router (making it two hops away), the TTL would be 253 upon arrival.

To complete the launch of the new internet service, ISP_A needs to ensure that routes are shared between different VRFs for Customer_A and Customer_B. Importing route-target 62:101 into the customer VRFs on R1 and R3 allows for the exchange of routes between these VRFs, facilitating the necessary connectivity for the new service. References := Cisco SPCOR

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.

 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.

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

 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.

The configuration shown in the exhibit enables IP flow information collection on the interface gigabitethernet0/1. This setup is used for network traffic analysis, and when applied, it provides data that includes the source interface of the traffic for traceback analysis. This is useful for identifying the origin of traffic, which can be critical in situations such as security incidents or network troubleshooting.

The configuration in Option A is correct for enabling dial-out telemetry streams using gRPC on devices with TLS disabled.

It uses model-driven telemetry (MDT), which is a new method of monitoring network devices. Unlike traditional methods that pull data from the device, MDT pushes data from the device to the collector.

In this configuration:

Telemetry is model-driven.

It specifies a destination group with an IP address and port number where the telemetry data will be sent.

The encoding is self-describing-gpb (Google Protocol Buffers).

The protocol used is TCP.

This setup ensures that telemetry data is sent to the specified collector without requiring TLS encryption.

 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.

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

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

PCE – 1,2,5

PCC- 3,4

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.

The disruption in IS-IS connectivity between R1 and R2, despite the interfaces being up, suggests an issue with packet handling or MTU configuration. Action A, disabling padding for hello packets under the serial interface on R2, is necessary because excessive padding can lead to issues in processing hello packets effectively. Action C, changing the MTU to 1500 bytes on R2, addresses potential MTU mismatch issues. MTU mismatches are common problems that can interrupt connectivity in networks using routing protocols like IS-IS; ensuring both routers operate at the same MTU can resolve this issue.

References := The explanation is derived from the principles outlined in Cisco’s Implementing and Operating Cisco Service Provider Network Core Technologies, which emphasizes the importance of proper packet handling and MTU configuration for maintaining IS-IS connectivity.

 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.

Router R1 establishes TCP connections that are authenticated with an MD5 password. In the context of BGP (Border Gateway Protocol), TCP is used for establishing connections, and MD5 passwords can be used for authentication to enhance security.

 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

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

In an MPLS network, the Label Distribution Protocol (LDP) is used to distribute labels which can include segment prefixes. LDP is a protocol that automatically generates and exchanges labels between routers, allowing for the forwarding of packets along a predetermined path without the need for complex lookups in a routing table at every hop.

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

 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.

R1

R2

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.

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)

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.

 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.

 The configuration in the exhibit shows the implementation of Nonstop Forwarding (NSF) with OSPF. NSF is used to minimize the downtime of neighbor relationships during a Route Processor (RP) switchover. The nsf command enables NSF, and ietf specifies the use of the IETF standard for graceful restart in OSPF. The restart interval 90 sets the time, in seconds, within which the restarting router should complete its restart, helping to maintain uninterrupted forwarding despite the switchover.

In Cisco’s path selection process, the weight attribute is the first criterion for selecting a path. It is a Cisco-specific parameter, local to the router, and it is not propagated in routing updates. The path with the highest weight is preferred. Therefore, configuring a high weight on the peer to ASN 4567 will make Router R1 prefer this path for all outbound traffic directed towards ASN 4567. References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Cisco SPCOR Training & Certification

 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

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.

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

References :=

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

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.

 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.

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.

When there is an LSP breakage during the testing of MPLS OAM ping capabilities, the ingress MPLS router does not receive any reply because MPLS OAM ping is used to verify connectivity over Label Switched Paths (LSPs), and if an LSP is broken, the echo request will not reach the egress router, resulting in no echo reply being sent back.

 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.

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.

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.

When creating new Cisco MPLS TE tunnels, the headend router sends a Path message to reserve bandwidth on the path to the tunnel’s tailend router. The Path message is part of the RSVP (Resource Reservation Protocol) used in signaling and establishing MPLS TE tunnels. It carries information about the requested resources and desired parameters for the tunnel123. References: Configuring MPLS TE RSVP, MPLS TE RSVP-TE, MPLS TE Theory.

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.

To mitigate DDoS attacks in a BGP environment, an engineer can apply BGP FlowSpec, which allows for the creation of traffic filtering policies that can be distributed across the network. This configuration enables the network to respond quickly to DDoS attacks by filtering or redirecting malicious traffic based on predefined criteria, such as source IP, destination IP, and port numbers456.

 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.

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.

 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.

The correct command to authenticate the OSPF neighbor between PE-A and PE-B using MD5 is found in Option A. In this option, the command ip ospf message-digest-key 1 md5 44578611 is used to configure OSPF MD5 authentication on an interface with the key ID as 1 and key string as 44578611. The second command ip ospf authentication key-chain 44578611 is used to enable OSPF authentication on an interface and associate it with a specific key chain. References := Cisco - Implementing and Operating Cisco Service Provider Network Core Technologies

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.

 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.

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

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.

IS-IS uses NET addresses to identify each router in the network, and the NET address of each router must be unique. In order for IS-IS to establish connectivity between R1 and R3, the NET address of R3 must be different from the NET address of R1, but it must also follow the same structure. In this case, the NET address of R1 is 49.0133.532b.ca14.6915.21311.F40F.1B3a.ba10.00, so the NET address of R3 must be 49.0133.532b.ca14.6915.21311.F40F.1B4a.bb87.00.

Best – 50.50.50.2

2nd Best – 40.40.40.2

3rd Best – 20.20.20.2

44th Best – 30.30.30.2

R1

key chain AUTH_ISIS

key 2

key-string C1sco!

exit

int range et0/0 , et1/0

isis authen key-chain AUTH_ISIS

ip isis

isis metric 15

Copy run start

R2

key chain AUTH_ISIS

key 2

key-string C1sco!

exit

int range et0/0 , et1/0

isis authen key-chain AUTH_ISIS

ip isis

isis metric 20

Copy run start

R3

key chain AUTH_ISIS

key 2

key-string C1sco!

exit

int range et0/0 , et1/0

isis authen key-chain AUTH_ISIS

ip isis

isis metric 25

Copy run start

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

 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.

The requirement is to redistribute routes with a tag of 80 and IP prefixes other than 192.168.10.20/24 from Level 1 into Level 2, and also to configure route leaking from Level 2 into the Level 1 domain for routes that are tagged with only 50 or 40. Option B, “Add match ip address 152 in route-map redist1-2”, meets the first requirement as it allows all IP prefixes except for the specified one (192.168.10.20/24) to be redistributed from Level-1 to Level-2 when they have a tag of 80.

This configuration sets up policing rules for different protocols including CDP (Cisco Discovery Protocol) and ARP (Address Resolution Protocol), with specific rate limits for invalid packets as well as CDP and ARP protocols. References: Implementing and Operating Cisco Service Provider Network Core Technologies source documents or study guide

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

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.

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.

 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

 In Cisco IOS XR, to send BGP IPv4 labels to build inter-domain Label Switched Paths (LSPs), the configuration command used is router bgp 65515 neighbor 172.16.70.23 address-family ipv4 labeled-unicast. This command specifies that the router should use the BGP labeled unicast address family for the specified neighbor, which enables the exchange of label information along with the IPv4 routing information, facilitating MPLS LSP creation for inter-domain traffic.

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

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.

 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.

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

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

Solution

R3

router bgp 65413

add ipv4

nei 2.2.2.2 allowas-in

nei 4.4.4.4 allowas-in

add ipv6

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

end

copy run start

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

R2

router bgp 65413

nei 1.1.1.1 as-override

nei 3.3.3.3 as-override

end

copy run start

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

R3

router bgp 65413

nei 10.3.4.2 remot 65412

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

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

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

add ip4

nei 10.3.4.2 act

ex

add ipv6

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

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

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

end

copy run start

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

R4

router bgp 65412

nei 10.3.4.1 remot 65413

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

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

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

add ipv4

nei 10.3.4.1 remot act

nei 10.3.4.1 prefix-limit 10

add ipv6

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

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

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

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

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

end

copy run start

The mpls ldp graceful-restart command is applied in the global configuration mode in IOS XE Software. This command enables MPLS LDP Graceful Restart, which assists a neighboring router with MPLS LDP Stateful Switchover/Nonstop Forwarding (SSO/NSF) Support and Graceful Restart to recover gracefully from an interruption in service without losing its MPLS forwarding state1.