Cisco 350-501 Online Practice Questions and Exam Preparation

Cisco 350-501 Online Questions & Answers

• Question 491:

  What is the primary role of a BR router in a 6rd environment?

  A. It provides connectivity between end devices and the IPv4 network
  B. It provides IPv4-in-IPv6 encapsulation
  C. It connects the CE routers with the IPv6 network
  D. It embeds the IPv4 address in the 2002::/16 prefix
  C. It connects the CE routers with the IPv6 network

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  Explanation

  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 router.

  NetworkLessons.com, "IPv6 6RD (Rapid Deployment)" RFC 5969, "IPv6 Rapid Deployment on IPv4 Infrastructures (6rd) ?Protocol Specification"

• Question 492:

  DRAG DROP

  Drag and drop the functions from the left onto the correct Path Computation Element Protocol roles on the right.

  Select and Place:

  

  

  Explanation

  Explanation/Reference:

  Path Computation Element (Calculates paths through the network, keeps TE topology database information, sends path status updates) Path computation Client (sends path calculation request, sends path creation request)

  Path Computation Element (PCE) Represents a software module (which can be a component or application) that enables the router to compute paths applying a set of constraints between any pair of nodes within the router's TE topology database. PCEs are discovered through IGP.

  Path Computation Client (PCC) Represents a software module running on a router that is capable of sending and receiving path computation requests and responses to and from PCEs. The PCC is typically an LSR (Label Switching Router).

  Rerefing to rfc4657 section-5.1.4 https://tools.ietf.org/html/rfc4657#section-5.1.4 The PCE facilitates path computation requests from Path Computation Clients (PCCs) to Path Computation Elements (PCEs). Path Computation Client requests path computation (calculation in our case) to Path Computation Element.

  - Rerefing to rfc4657 section-5.3.3 https://tools.ietf.org/html/rfc4657#section-5.3.3 If an LSP fails owing to the failure of a link or node that it traverses, a new computation request may be made to a PCE in order to repair the LSP. Since the PCC cannot know that the PCE's TED has been updated to reflect the failure network information, it is useful to include this information in the new path computation request.

  As a conclusion, PCC requests path calculation and includes update request in path calculation request.

  https://www.cisco.com/c/en/us/td/docs/routers/crs/software/crs_r5-3/mpls/configuration/guide/b-mpls-cg53x-crs/b-mpls-cg53x- crs_chapter_0110.html#con_1279822

• Question 493:

  What occurs when a high bandwidth multicast stream is sent over an MVPN using Cisco hardware?

  A. The traffic uses the default MDT to transmit the data only if it is a (S, G) multicast route entry.
  B. A data MDT is created to if it is a (*, G) multicast route entries.
  C. A data and default MDT are created to flood the multicast stream out of all PIM-SM neighbors.
  D. A data MDT is created to allow for the best transmission through the core for (S, G) multicast route entries.
  D. A data MDT is created to allow for the best transmission through the core for (S, G) multicast route entries.

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  Explanation

  In Cisco hardware, when a high bandwidth multicast stream is sent over a Multicast VPN (MVPN), a data Multicast Distribution Tree (MDT) is specifically created for that stream. This data MDT is used in addition to the default MDT, which is used for lower-bandwidth or control traffic. The purpose of the data MDT is to optimize the transmission of high-bandwidth streams through the core of the network, ensuring that the multicast traffic is only sent to those PE routers that have local receivers for the multicast group in question. This mechanism helps in efficiently using network resources and provides a scalable solution for transmitting high-bandwidth multicast streams.

  The explanation is based on the concepts outlined in the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course, which covers the configuration, verification, troubleshooting, and optimization of Service Provider IP network infrastructures, including advanced topics like MVPN and MDTs

• Question 494:

  Which action occurs during the traceback phase of the six-phase approach to service provider security?

  A. Trace the attack that flows from the attacked sections of the network toward the network edges
  B. Detect unusual activity or behavior and activate appropriate measures after an alert is raised
  C. Review the whole attack-handling process
  D. Mitigate the attack that flows using various mechanisms
  A. Trace the attack that flows from the attacked sections of the network toward the network edges

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  Explanation

  Traceback Phase Assuming you have identified the attack vector in the preceding phase, you now need to identify the ingress points in order to mitigate the attack efficiently. The traceback phase entails tracing the attack flows from the attacked sections of the network toward the network edges. You can take a hop-by-hop approach tracking the sources upstream from the victim toward network edges, or you can directly jump on the network ingress points to check them for the presence of attack flows. You can track flows through the network in various ways: through ACLs (with or without the log-input clause), by deploying NetFlow, or by using backscatter mechanisms.

  https://sec.cloudapps.cisco.com/security/center/resources/service_provider_infrastructure_security.html

• Question 495:

  Refer to the exhibit.

  

  Which show command shows statistics for the control plane policy and is used to troubleshoot?

  A. show control-plane CoPP
  B. show policy control-plane
  C. show control-plane
  D. show policy-map control-plane
  D. show policy-map control-plane

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  Explanation

  The command "show policy-map control-plane" is used to display the control plane policies applied on a Cisco device, including the statistics related to packets matched by the class-maps of the policy-map. In this context, it helps in troubleshooting by providing detailed insights into how different types of traffic are being processed and controlled as they pass through the control plane.

  Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) official course materials available on Cisco's website.

• Question 496:

  

  Refer to the exhibit. R1 has two upstream Tier 1 service providers. BGP is in use as the exterior routing protocol, and ISP_A and ISP_B are sending the full BGP table. A network engineer must assign local-preference 70 to all routes with multiple exit discriminator 30. Which configuration must the network engineer apply?

  

  A. Option A
  B. Option B
  C. Option C
  D. Option D
  C. Option C

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  Explanation

  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

• Question 497:

  Refer to the exhibit.

  

  A network operator working for a telecommunication company with an employee ID: 4350:47:853 must implement an IGP solution based on these requirements:

  1. Subnet 10.50.10.0 traffic must exit through the R1 router to connect with the Syslog server.

  2. Subnet 10.50.20.0 traffic must exit through the R2 router to connect with the NTP server.

  3. In case of link failure between R2 and R4, traffic must be routed via R1 and R3.

  Which two configurations must be implemented on R5 to meet these requirements? (Choose two.)

  A. Apply a route policy to redistribute 10.50.0.0 prefixes in OSPF to ISIS and ISIS to OSPF.
  B. Apply a route policy to redistribute 10.50.20.0 from ISIS-L2 to OSPF Area 0 at a higher cost.
  C. Enable a route policy to advertise 10.50.20.0 in ISIS-L2 at a higher cost.
  D. Apply a route policy to redistribute 10.50.10.0 from OSPF Area 0 to ISIS-L2 at a lower cost.
  E. Enable a route policy to advertise 10.50.10.0 In OSPF Area 0 at a low cost.
  B. Apply a route policy to redistribute 10.50.20.0 from ISIS-L2 to OSPF Area 0 at a higher cost.
  E. Enable a route policy to advertise 10.50.10.0 In OSPF Area 0 at a low cost.

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  Explanation

• Question 498:

  Refer to the exhibit.

  

  PE-A

  vrf definition Customer-A rd 65000:1111

  router-target export 65000:1111

  router-target import 65000:1111 !

  address-family ipv4 mdt default 233.15.38.120 mdt data 233.15.38.121 0.0.0.0 threshold 100 mdt mtu 5000 !

  interface GigabitEthernet0/0 vrf forwarding Customer-A ip address 10.10.10.1 255.255.255.252 !

  ip multicast-routing vrf Customer-A

  An engineer is implementing Auto-RP and reviewing the configuration of the PE-A.

  Which configuration permits Auto-RP messages to be forwarded over this interface?

  A. PE-A(config-if)#ip pim sparse-mode
  B. PE-A(config-if)#no ip pim bsr-border
  C. PE-A(config-if)#ip igmp version 3
  D. PE-A(config-if)#ip pim sparse-dense-mode
  D. PE-A(config-if)#ip pim sparse-dense-mode

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  Explanation

  Option D is the correct answer because, in the context of Auto-RP, sparse-dense mode allows the router to forward Auto-RP messages. Auto-RP uses dense mode multicast groups (224.0.1.39 and 224.0.1.40) to advertise RP mapping information, so enabling sparse-dense mode on the interface ensures that it can process both types of multicast traffic.

  References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) official course materials, which can be found here.

• Question 499:

  Refer to the exhibit.

  R1

  interface gigabitethernet1/0/0 ipv6 enable ipv6 ospf 1 area 1

  interface gigabitethernet2/0/0 ipv6 enable ipv6 ospf 1 area 2 An engineer implemented OSPF neighbor relationship on an IOS device. Which configuration must be applied to get the OR/BOR election removed from interfaces running OSPF?

  A. ip ospf network broadcast on interfaces running OSPF
  B. ip ospf network point-to-point on interfaces running OSPF
  C. ip ospf network multipoint-point on interfaces running OSPF
  D. ip ospf network non-broadcast on n:erfaces running OSPF
  B. ip ospf network point-to-point on interfaces running OSPF

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  Explanation

• Question 500:

  Refer to the exhibit.

  

  An ISP provides shared VoIP Extranet services to a customer in VRF-100 with these settings:

  1. The VoIP services are hosted in the 198.19.1000/24 space.

  2. The customer has been assigned the 198.18.10/29 IP address bloc*.

  3. VRF-100 is assigned Import and export route target 85010:100.

  Which configuration must the engineer Apply to PE-1 to provision VRF-100 and provide access to the shared services?

  A. vrf definition VRF-100rd 172.17.255.1:100!address-family ipv4export map VRF-100-EXPORTimport map VRF-100-IMPORTexit-address-family!route-map VRF-100-EXPORT permit 10match ip address prefix-list VRF-100-ALLOWED-EXPORTset extcommunity rt 65010:100 65010:2999route-map VRF-100-EXPORT permit 20set extcommunity rt 65010:100!route-map VRF-100-IMPORT permit 10match extcommunity VRF-100-RT SHARED-SERVICES!ip extcommunity-list standard SHARED-SERVICES permit rt 65010:1999ip extcommunity-list standard VRF-100-RT permit rt 65010:100ip prefix-list VRF-100-ALLOWED-EXPORT seq 5 permit 198.18.1.0/29
  B. vrf definition VRF-100rd 172.17.255.1:100!address-family ipv4export map VRF-100-EXPORTroute-target import 65010:100route-target import 65010:2999exit-address-family!route-map VRF-100-EXPORT permit 10match ip address prefix-list VRF-100-ALLOWED-EXPORTset extcommunity rt 65010:100 65010:1999route-map VRF-100-EXPORT permit 20set extcommunity rt 65010:100!ip prefix-list VRF-100-ALLOWED-EXPORT seq 5 permit 198.18.1.0/29
  C. vrf definition VRF-100rd 172.17.255.1:100!address-family ipv4export map VRF-100-EXPORTroute-target import 65010:100route-target import 65010:1999exit address-family!route-map VRF-100-EXPORT permit 10match ip address prefix-list VRF-100-ALLOWED-EXPORTset extcommunity rt 65010:100 65010:2999route-map VRF-100-EXPORT permit 20set extcommunity r 65010:100!ip prefix-list VRF-100-ALLOWED-EXPORT seq 5 permit 198.18.1.0/29
  D. vrf definition VRF-100rd 172.17.255.1:100!address-family ipv4route-target export 65010:100route-target export 65010:1999route-target import 65010:100route-target import 65010:2999exit-address-family
  D. vrf definition VRF-100rd 172.17.255.1:100!address-family ipv4route-target export 65010:100route-target export 65010:1999route-target import 65010:100route-target import 65010:2999exit-address-family

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  Explanation