Down To Date 642-887 Rapidshare 2021

NEW QUESTION 1
Which three statements are correct regarding ping mpls command operations? (Choose three.)

• A. MPLS OAM has to be enabled on the router using the mpls oam command.
• B. They use a 127/8 address as the destination address in the MPLS echo request packet.
• C. They use ICMP echo request and ICMP echo reply packets.
• D. They are used to test for a broken LSP.
• E. If there is a broken LSP, instead of using label switching, the packet can still be forwarded based on the destination IP address in the mpls ping echo request packet.

Answer: ABD

Explanation:
How MPLS Ping works?
MPLS Ping doesn’t rely on ICMP echo messages. Instead it uses UDP protocol with both source and destination port as 3503 and relies on MPLS Echo request and MPLS Echo
reply.
When MPLS ping is triggered from any MPLS router, it will generate UDP segment with source/destination port as 3503. The source address will be selected as usual while the destination address will be 127.0.0.1. The IP TTL will be set to 1.
Below is a sample IP format when MPLS Ping is originated from R5 to 150.1.6.6/32,

Now the originating LSR will look into the LFIB and populate the label header with respective labels to reach the FEC, in our case 150.1.6.6/32.
R4 on receiving the MPLS packet will be able to send to the actual destination only if the LSP is end to end. If the LSP is broken between R4 and R6, R4 will look into the destination IP address which will be 127.0.0.1 and won’t be able to perform IP forwarding. As per RFC 1812, a router should not forward any packet that has destination address of 127.0.0.0/8

NEW QUESTION 2
Scenario:




On P2IOS-XR router what is targeted LDP hellos hold time on LDP session with 10.0.1.1:0 LDP ID?

• A. 90 sec
• B. 10 sec
• C. 3 sec
• D. 8.6 sec

Answer: A

Explanation:
Issue on P2: show mpls ldp discovery (details). Ps: The command show mpls ldp parameter is not Implemented.
Look at the end, you will see the hello and the holdtime values for the target neighbour. Be careful he is asking for "targeted LDP hellos hold time". No other command will work!!! At the end of the show result you will see something looks like the following:
LDP discovery sources:
Targeted Hello 10.0.2.1 -> 10.0.1.1 active, passive;
Hello: 30 sec
holdtime: 90 sec

NEW QUESTION 3
An engineer is working in a service provider environment to troubleshoot a MPLS VPN. The engineer determines that LDP neighborship is flapping between two routers and causing disruption to the traffic. Which LDP feature can help to solve the issue?

• A. LDP Discovery
• B. LDP auto-configuration
• C. LDP graceful-restart
• D. LDP NSF

Answer: C

NEW QUESTION 4
LDP session protection uses which one to maintain the LDP session between LDP neighbors?

• A. LDP NSF
• B. LDP NSR
• C. backup-targeted LDP hellos
• D. BFD
• E. LDP-IGP synchronization

Answer: C

NEW QUESTION 5
Which configuration fulfills the requirement of configuring LDP with Cisco Nonstop Forwarding on a router with 5 minutes time to hold the forwarding table information and 1 minute retry timer value for an LDP connection?

• A. mpls ldp graceful-restartgraceful-restart forwarding state-holdtime 5 graceful-restart reconnect-timeout 1 interface GigabitEthernet0/0/0/0!
• B. mpls ldp graceful-restartgraceful-restart forwarding state-holdtime 300 graceful-restart reconnect-timeout 60 interface GigabitEthernet0/0/0/0!
• C. mpls ldp nsrgraceful-restartgraceful-restart forwarding state-holdtime 300 graceful-restart reconnect-timeout 60 interface GigabitEthernet0/0/0/0!
• D. mpls ldp nsrgraceful-restartgraceful-restart forwarding state-holdtime 5 graceful-restart reconnect-timeout 1 interface GigabitEthernet0/0/0/0!

Answer: B

NEW QUESTION 6
DRAG DROP

• A. Mastered
• B. Not Mastered

Answer: A

Explanation:
Place the options in the following order: Traffic Policing
WRED LLQ
Traffic Shaping

NEW QUESTION 7
Which statement describes the QoS behavior between P and PE routers of an MPLS provider network for an L3VPN service?

• A. The PE function honors DSCP markings set by the CE.
• B. The customer and provider must agree on DSCP classification and traffic priorities.
• C. Classification of customer traffic is handled by the P router.
• D. The PE function cannot map DSCP markings to MPLS EXP bits.

Answer: B

NEW QUESTION 8
Which two values must be specified in a Cisco NBAR configuration? (Choose two.)

• A. port number
• B. IP precedence
• C. neighbor discovery address
• D. CoS
• E. transport protocol

Answer: AE

NEW QUESTION 9
You are tasked to enable LDP on many of the interfaces on the Cisco CRS-3 router, and because there are many interfaces that need to have LDP enabled, you mistakenly did not enable LDP on all the required interfaces. To prevent this issue from happening again in the future, what could you do the next time you need to enable LDP on many interfaces?

• A. use the mpls ldp auto-config command under the IGP routing process
• B. use the mpls ldp sync command under the IGP routing process
• C. use the interface all command under the MPLS LDP process
• D. use the discovery command under the MPLS LDP process

Answer: A

NEW QUESTION 10
When a link flaps, an mpls ldp session will also flap. Which feature minimizes traffic loss and provides faster convergence after the link is re-established?

• A. BFD
• B. MPLS LDP IGP SYNC
• C. graceful restart
• D. LDP session protection
• E. LDP nonstop routing

Answer: D

NEW QUESTION 11
When implementing MPLS TE tunnels on Cisco IOS XR routers, what is the tunnel setup and hold priority value range, and which value has the highest priority?

• A. 0-63, where 0 is the highest priority
• B. 0-63, where 63 is the highest priority
• C. 0-7, where 0 is the highest priority
• D. 0-7, where 7 is the highest priority

Answer: C

NEW QUESTION 12
Which configuration can a network engineer use to establish high availability for LDP in an MPLS setup?

• A. mpls ldpgraceful-restart graceful-restartgraceful-restart forwarding state-holdtime 180 graceful-restart reconnect-timeout 15 interface HundredGigE0/4/0/0
• B. mpls ldp graceful-restartgraceful-restart forwarding state-holdtime 180 graceful-restart reconnect-timeout 15
• C. mpls ldpsession protection for peer_acl duration 60 ipv4 access-list peer_acl10 permit ip host 192.168.10.1 any
• D. router ospf 1 mpls ldp sync mpls ldpigp sync delay 30
• E. mpls ldprouter-id loopback0 discovery hello holdtime 15 discovery hello interval 5

Answer: A

NEW QUESTION 13
On the Cisco IOS XR, which MQC configuration is different than on the Cisco IOS and IOS XE?

• A. On the Cisco IOS XR, WRED can only be applied in the output direction.
• B. On the Cisco IOS XR, marking can only be applied in the input direction.
• C. On the Cisco IOS XR, LLQ can be applied in the input or output direction.
• D. On the Cisco IOS XR, LLQ can use up to four priority queues: level 1, level 2, level 3, and level 4.

Answer: C

NEW QUESTION 14
A network engineer must analyze RSVP-TE signaling on a syslog server. Which three RSVP messages are valid? (Choose three.)

• A. RSVP PATH
• B. RSVP RESERVATION
• C. RSVP ESTABLISHED
• D. RSVP PATH TEAR
• E. RSVP KILL
• F. RSVP INIT

Answer: ABD

NEW QUESTION 15
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 16
What is a primary difference between QoS operations on IOS and IOS XR?

• A. IOS XR features multi-level LLQ
• B. IOS XR automatically polices the LLQ
• C. IOS XR does not support NBAR
• D. IOS XR cannot set FR-DE

Answer: B

NEW QUESTION 17
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 18
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 19
Which field in the MPLS shim header is used to support different QoS markings?

• A. IP precedence
• B. DSCP
• C. EXP
• D. ToS
• E. S
• F. Label

Answer: C

Explanation:
MPLS EXP Marking
The three MPLS EXP (experimental) bits in the shim header of an input or output MPLS packet header may be set or changed by a user configured value

NEW QUESTION 20
Which two values are class-selector DSCP values? (Choose two.)

• A. 001001
• B. 000111
• C. 111000
• D. 100000
• E. 000001

Answer: CD

NEW QUESTION 21
Which option describes what happens when a labelled packet with a TTL of 1 is received by an LSR?

• A. The packet is forwarded on to the next router where its TTL expires and from where an ICMP "time exceeded" message is generated and routed back to the source.
• B. The packet is dropped and an ICMP "time exceeded" message is IP routed back to the sender.
• C. The packet is dropped and an ICMP "time exceeded" message is label-switched from the expiring router back on a new path toward the source.
• D. The packet is dropped and an ICMP "time exceeded" message is label-switched from the expiring router on the same label switched path toward the destination and then back to the originating source.
• E. The packet is forwarded on to the next router where its TTL expires and from where an ICMP "time exceeded" message is generated and label switched back to the source.

Answer: D

NEW QUESTION 22
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 23
Refer to the exhibit. Based on the raw format of an MPLS header captured by a traffic analyzer, what is the value of the MPLS EXP field?

• A. 1
• B. 255
• C. 5
• D. 29

Answer: C

NEW QUESTION 24
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