Updated 642-887 Braindumps 2021

NEW QUESTION 1
Which three options can an engineer select for a traffic policer in case the traffic rate is less than the conform burst? (Choose three.)

• A. Drop the packet.
• B. Transmit the packet.
• C. Set the CoS value and drop the packet.
• D. Set the DSCP value and drop the packet.
• E. Keep the packet in the buffer.
• F. Set the QoS group and drop the packet.

Answer: ABF

NEW QUESTION 2
Given this configuration of an interface for MPLS traffic engineering on a Cisco IOS XE router:
interface POS1/1/0 mpls traffic-eng tunnels ip rsvp bandwidth 5000
Which option lists the equivalent configurations required on a Cisco IOS XR router?

• A. interface POS1/1/0 mpls traffic-eng tunnels ip rsvp bandwidth 5000
• B. mpls traffic-eng interface POS1/1/0
• C. mpls traffic-eng interface POS1/1/1 bandwidth 5mb
• D. mpls traffic-eng interface POS1/1/0 rsvpinterface POS1/1/0
• E. mpls traffic-eng interface POS1/1/0 rsvpinterface POS1/1/0 bandwidth 5000

Answer: E

NEW QUESTION 3
A service provider experiences routing issues in a customer MPLS network. The customer has two sites that are connected over its core. Which feature can be used for troubleshooting?

• A. disabling of Cisco Express Forwarding, to enable the use of LSP Ping and LSP Traceroute to verify the IP routing path
• B. redistribution between the BGP IPv4 and VPNv4 address families, to use labels to forward the customer packets
• C. LSP Ping, to confirm that the label-switched path is used for transport
• D. traceroute, to verify the label-switched path that is used for point-to-multipoint

Answer: C

NEW QUESTION 4
Which method maps MPLS EXP bit 5 to COS 5 on Cisco IOS XE?

• A. configure terminal class-map match expmatch mpls experimental topmost 5exitpolicy-map EXP2Cos class expset cos 5 exitclass class-default random-detecinterface fastethernet 0/0 service-policy output EXP2Cos
• B. configure terminalclass-map match expmatch mpls experimental topmost 5 exitpolicy-map EXP2Cos class expset cos 5 exitclass class-default random-detecinterface fastethernet 0/0 service-policy input EXP2Cos
• C. configure terminal class-map match exp match mpls cos 5 exitpolicy-map EXP2Cos class expset mpls experimental topmost 5 exitclass class-default random-detecinterface fastethernet 0/0 service-policy output EXP2Cos
• D. configure terminalclass-map match exp match mpls cos 5 exitpolicy-map EXP2Cos class expset mpls experimental topmost 5 exitclass class-default random-detecinterface fastethernet 0/0 service-policy output EXP2Cos exitcommit
• E. configure terminalip access-list 101 permit ip any any mpls experimental 5 class-map match expmatch access-group 101 exitpolicy-map EXP2Cos class expset cos 5 exitclass class-default random-detecinterface fastethernet 0/0 service-policy output EXP2Cos exit

Answer: A

NEW QUESTION 5
An engineer looks at packet captures and sees that the MPLS header field of a packet indicates a bottom of stack field of 0. What can the engineer conclude from this information?

• A. The packet is an AToM packet
• B. One label is on the packet
• C. At least one more MPLS label is on the packet
• D. No labels are on the packet

Answer: C

NEW QUESTION 6
Refer to the exhibit.

MPLS TE Tunnel 138 has a headend R1 and a tailend R4, and uses path R1-R2-R4 as the primary LSP. The path R1-R2-R3-R4 should be implemented as a backup LSP in case the R2-R4 link fails. To which interface should the appropriate configuration be applied to accomplish this?
A)

B)

C)

D)

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

Answer: C

NEW QUESTION 7
Which statement defines how MPLS LDT Graceful Restart works after a service interruption?

• A. It works independent of neighboring routers to recover MPLS forwarding information
• B. It works by helping all neighboring MPLS LDP routers to recover MPLS forwarding information
• C. It works by helping neighboring routers with MPLS LDP SSO/NSF and Graceful Restart to recover MPLS forwarding information
• D. It works independent of neighboring non-LDP Graceful Restart routers to recover MPLS forwardinginformation

Answer: C

NEW QUESTION 8
In which two Cisco IOS XR configuration modes can mpls ldp igp sync be configured? (Choose two.)

• A. config-ldp
• B. config-if
• C. config-ospf-ar
• D. config-ospf
• E. config-isis

Answer: CD

NEW QUESTION 9
Which option describes the IPv6 flow label field?

• A. a 3-bit field used for marking a traffic flow
• B. an 8-bit field used for labeling a traffic flow
• C. a 20-bit field used to tag a traffic flow throughout the network
• D. an 8-bit field out of which the first 6 are used to classify packets

Answer: C

NEW QUESTION 10
Which option is a Cisco-recommended congestion management or queuing method for real-time traffic for voice and video?

• A. CB-WFQ
• B. PQ
• C. WFQ
• D. LLQ

Answer: D

NEW QUESTION 11
Which two advantages are reasons that service providers might deploy MPLS? (Choose two.)

• A. to avoid using IGP in the core
• B. to facilitate smooth migrations between legacy WAN technologies
• C. to reduce the throughput overhead of full IPv4/IPv6 headers when traversing the core
• D. to reduce the computational requirements that are placed on router CPUs
• E. to reduce configuration and feature requirements in the core

Answer: CD

NEW QUESTION 12
An engineer wants to extend the trust boundary to a Cisco IP Phone. Which protocol should be used?

• A. CDP
• B. CoS
• C. ToS
• D. 802.1Q

Answer: A

NEW QUESTION 13
The network architecture team is proposing to enable Cisco MPLS TE over the entire
service provider core network. Which two options are benefits of Cisco MPLS TE that affect their decision? (Choose two.)

• A. Cisco MPLS TE optimizes network resources.
• B. Cisco MPLS TE data flows independent from the underlying IGP.
• C. Cisco MPLS TE increases the data forwarding rate.
• D. Cisco MPLS TE tunneling does not require maintenance.
• E. Cisco MPLS TE offers network resource reservation, which removes any need for QoS MQC policies.

Answer: AB

NEW QUESTION 14
DRAG DROP

• A. Mastered
• B. Not Mastered

Answer: A

Explanation:
1) Build RIB
2) Assign labels
3) Advertise Labels 4)Build LFIB
1) Build RIB
2) Assign labels
3) Advertise Labels
4) Build LFIB

NEW QUESTION 15
Scenario:




From PE8 router, what is the label action used to reach the P2 loopback 0 interface 10.0.2.1/32?

• A. Swap label 35 with label 16004
• B. Push label 16004
• C. Pop label 35
• D. Pop label 16009
• E. Push Label 16009
• F. Swap label 35 with label 16009

Answer: C

Explanation:
show mpls forwarding-table , find prefix 10.0.2.1 and you will see there under outgoing Label "Pop Label" (This is actually logic because the prefix is directly connected and therefore the packet will forward without label). If the router should forward any packet to that prefix, the packet should be received with Local label on PE8 (Local Label = 35), the router will remove it and forward it without Label.

NEW QUESTION 16
Cisco MPLS TE resource attributes that are configured locally for each link are distributed to the headend router of the traffic engineering tunnel using which protocol?

• A. BGP
• B. MP-BGP
• C. LDP
• D. RSVP
• E. OSPF or IS-IS with TE extension

Answer: E

NEW QUESTION 17
The Cisco IOS and IOS XE qos pre-classify command allows which kind of packet classification on IP packets that are encapsulated with GRE and IPsec?

• A. allows for packets to be classified based on the ToS byte values before packet encryption
• B. allows for packets to be classified based on the ToS byte values after packet encryption
• C. allows for packets to be classified based on the packet payload before packet encryption
• D. allows for packets to be classified based on the packet payload after packet encryption
• E. allows for packets to be classified based on the packet header parameters other than the ToS byte values after packet encryption

Answer: A

Explanation:
http://www.cisco.com/en/US/tech/tk543/tk545/technologies_tech_note09186a008017405e. shtml
The qos pre-classify command
When packets are encapsulated by tunnel or encryption headers, QoS features are unable to examine the original packet headers and correctly classify the packets. Packets traveling across the same tunnel have the same tunnel headers, so the packets are treated identically if the physical interface is congested. With the introduction of the Quality of Service for Virtual Private Networks (VPNs) feature, packets can now be classified before tunneling and encryption occur.
In this example, tunnel0 is the tunnel name. The qos pre-classify command enables the QoS for VPNs feature on tunnel0:
Router(config)# interface tunnel0
Router(config-if)# qos pre-classify

NEW QUESTION 18
Which two factors must you consider when configuring MPLS EXP? (Choose two.)

• A. MPLS EXP marking is supported in the egress direction
• B. A packet that IP ToS classifies at ingress can be reclassified by MPLS EXP at egress
• C. MPLS EXP marking is supported in the ingress direction
• D. MPLS EXP classification for bridged MPLS packets on EVCs is supported
• E. A packet that MPLS classifies at ingress can be reclassified by IP ToS at egress

Answer: CE

NEW QUESTION 19
When implementing MPLS DS-TE on Cisco IOS XR routers, all aggregate Cisco MPLS TE traffic is mapped to which class type by default?

• A. class-type 0 (bandwidth global pool)
• B. class-type 1 (bandwidth subpool)
• C. class-type 2 (bandwidth priority)
• D. class type class-default (bandwidth best-effort)

Answer: A

Explanation:
Differentiated Services Traffic Engineering
MPLS Differentiated Services (Diff-Serv) Aware Traffic Engineering (DS-TE) is an extension of the regular
MPLS-TE feature. Regular traffic engineering does not provide bandwidth guarantees to different traffic classes. A single bandwidth constraint is used in regular TE that is shared by all traffic. To support various classes of service (CoS), users can configure multiple bandwidth constraints. These bandwidth constraints can be treated differently based on the requirement for the traffic class using that constraint.
MPLS diff-serv traffic engineering provides the ability to configure multiple bandwidth constraints on an MPLSenabled interface. Available bandwidths from all configured bandwidth constraints are advertised using IGP.
TE tunnel is configured with bandwidth value and class-type requirements. Path calculation and admission control take the bandwidth and class-type into consideration. RSVP is used to signal the TE tunnel with bandwidth and class-type requirements.
Diff-Serv TE can be deployed with either Russian Doll Model (RDM) or Maximum Allocation Model (MAM) for bandwidth calculations.

NEW QUESTION 20
When configuring LLQ (strict priority queue) on a traffic class using the Cisco IOS XR priority command on a Cisco ASR9K router, which additional QoS command is required for this traffic class?

• A. shape
• B. police
• C. random-detect
• D. bandwidth

Answer: B

Explanation:
The Low Latency Queueing feature brings strict priority queueing to Class-Based Weighted Fair Queueing (CBWFQ).

NEW QUESTION 21
Refer to the exhibit.

While configuring traffic shaping, you implement this configuration. Which additional configuration is required?

• A. a service policy in the outbound direction on the interface
• B. a service policy in the inbound direction on the interface
• C. a default queue
• D. a second class, to match other traffic

Answer: A

NEW QUESTION 22
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