Quản trị mạng CCNP.Sem8.QoS

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Ngo Thanh Hien - Take Exam

Exam questions

Time remaining: 00: 49: 56

1 Which of the following choices represent the fundamental intelligent network services in Cisco’s AVVID? (Select four)

Quality of Service (QoS)

Reduces cost

Mobility and scalability

Security

High availability

2 What security policies should be implemented at the core?

Access-lists

Port security

Quality of Service commands for congestion management and avoidance

Traffic Filters

3 Which QoS mechanisms can you use on a converged network to improve VoIP quality? (Select three)

The use of a queuing method that will give VoIP traffic strict priority over other traffic

The use of RTP header compression for the VoIP traffic

The proper classification and marking of the traffic as close to the source as

possible

The use of 802.1QinQ trunking for VoIP traffic

The use of WRED

4 Switch SW1 is an IOS-based switch Which command could an administrator

use to establish a traffic policy on this IOS based switch?

traffic-list

route-map

policy-map

policy-list

None of the above

5 WRED is being configured on different network devices throughout the Cisco network What is true about WRED?

Cisco Express Forwarding cannot be enabled with WRED

WRED is useful when the bulk of traffic is not TCP/IP

The rate of packet-drop decreases as the average queue size increases, until the average queue size reaches the maximum threshold

Packets not flagged by IP precedence are randomly dropped when the average queue depth is above the minimum threshold

WRED defines packet-drop probability using an access list

All of the above

6 By default, which IP Precedence value is a DSCP value of 42 mapped?

0

1

2

3

4

5

7 When a PC is connected to the PC switch port on an IP Phone, how is QoS trust handled?

The IP Phone always trusts the class of service (CoS) information coming from the PC

The IP Phone never trusts the PC and always overwrites the CoS bits

QoS trust for the PC data is handled at the Catalyst switch port, not the IP

Phone

The Catalyst switch instructs the IP Phone how to trust the PC QoS information.

8 Which of the following QoS technologies classifies traffic entering a queue and services traffic based on dynamically observed traffic flows?

FIFO

WFQ

Custom Queuing

Priority Queuing

9 FIFO (First-In-First-Out) queue is associated with which QoS model?

Less than Best Effort Model

Best Effort Model

Differentiated Services Model (DiffServ)

Integrated Services Model (IntServ)

None of the above

10 In the three-layer hierarchical network design model; what’s associated with the access layer? (Select two)

optimized transport structure

high port density

boundary definition

data encryption

local VLANs

route summaries

11 You are a system administrator and you’ve recently implemented ‘tail drops’

on your network as a congestion avoidance mechanism Which QoS technique can you use to avoid the potential problems caused by tail drops?

CAR

WRED

CBWFQ

RSVP

12 What kinds of losses are observed on healthy networks during brief periods of congestion?

Loss due to jitter

Loss due to delay

Loss due to noise

Loss due to deliberately dropped packets

13 Which of the following network problems would indicate a need to implement QoS features? (Select three)

mis-routed packets

excess jitter

delay of critical traffic

packet loss due to congestion

data link layer broadcast storms

ftp connections unsuccessful

14 Someone asks you a question, “If I wanted to configure congestion avoidance, what mechanism randomly drops packets with a certain IP precedence value when the buffers fill to a predefined threshold?” Which mechanism is she asking about?

WFQ

CQ

LLQ

WRED

tail drop

15 What command is used to create a traffic policy on a Cisco IOS-based switch? route-map

traffic-list

policy-map

policy-list

16 Which command would you enter if you had a Cisco 3550 switch, and you

wanted to configure priority queuing on your gig0/1 interface?

Under the global configuration, configure "priority-queue out"

Under the global configuration, configure "interface priority-queue gig0/1"

Under the interface gig0/1, configure "priority-queue out"

Priority queuing is on by default

17 Which QoS technique avoids the problems that occur when tail drops are used

as the congestion avoidance mechanism on the router?

RSVP

WRED

CAR

CBWFQ

18 The Cisco network is using WRED for some QoS functions Which characteris-tic best describes weighted random early detection (WRED)?

It is well suited for UDP packets because of their connectionless state

It takes advantage of the TCP congestion control mechanism and drops packets selectively based on IP precedence

It should be used in multi-protocol environments where IPX/SPX packet can be dropped instead of UDP packets

It ensures that flows that use the least bandwidth are more likely to have pack-ets dropped

None of the above

19 The TestKing network is utilizing QoS techniques to prioritize their mission critical data What’s true about implementing QoS at the access, distribution, and core layers? (Select two)

QoS implementation is the same for the access, distribution, and core layers Classification and Marking should be done at the access layer

No QoS mechanisms are configured at the access layer since access layer

switches like the atalyst 2950 are not QoS capable

The high speed core layer only requires proper queuing (like LLQ) and dropping (like WRED) configurations

20 Which of the characteristics below is associated with the (QoS) Integrated

Ser-Ngo Thanh Hien - Take Exam

Exam questions

Time remaining: 00: 49: 56

1 Which of the following choices represent the fundamental intelligent network services in Cisco’s AVVID? (Select four)

Quality of Service (QoS)

Reduces cost

Mobility and scalability

Security

High availability

2 What security policies should be implemented at the core?

Access-lists

Port security

Quality of Service commands for congestion management and avoidance

Traffic Filters

3 Which QoS mechanisms can you use on a converged network to improve VoIP quality? (Select three)

The use of a queuing method that will give VoIP traffic strict priority over other traffic

The use of RTP header compression for the VoIP traffic

The proper classification and marking of the traffic as close to the source as

possible

The use of 802.1QinQ trunking for VoIP traffic

The use of WRED

4 Switch SW1 is an IOS-based switch Which command could an administrator

use to establish a traffic policy on this IOS based switch?