默认题库 - CCNP(642-845)

多选题

What are three problems with the tail drop mechanism of managing interface congestion？（）

A. Queuing introduces equal delays for packets of the same flow， resulting in jitter.
B. When congestion occurs， dropping affects most of the TCP sessions， which simultaneously back off and then restart again.
C. All buffers can temporarily be seized by aggressive flows， and normal TCP flows experience buffer starvation.
D. There is no differentiated drop mechanism. Higher priority traffic is dropped in the same way as best-effort traffic.
E. In TCP starvation， traffic exceeds the queue limit because of the bursty nature of packet networks. A router cannot handle multiple concurrent TCP sessions.
F. Global synchronization occurs because multiple TCP hosts reduce their transmission rates at random intervals in response to packet dropping

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多选题

Cisco provides two enhancements to 802.11 security which protect a WEP key from exploits. Which two technologies provide these security enhancements？（）

A. 802.1X
B. Cisco Temporal Key Integrity Protocol （CKIP）
C. Extensible Authentication Protocol-Flexible Authentication via Secure Tunneling （EAP-FAST）
D. Cisco Message Integrity Check （CMIC）
E. One-Time Passwords （OTP）
F. Advanced Encryption Standard （AES）

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多选题

What are three traffic descriptors that are used by the classification process to categorize packets that require special OoS handling？（）

A. Resource Reservation Protocol （RSVP）
B. IP precedence
C. traffic shaping
D. trust boundaries
E. DSCP
F. applicatio

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多选题

Which three options are prerequisites to configuring Cisco AutoOoS？（）

A. Cisco Express Forwarding （CEF） must be globally enabled.
B. Prior to the enabling of the Cisco AutoOoS feature， the bandwidth command must be applied on all interfaces or subinterfaces.
C. After the enabling of the Cisco AutoOoS feature， the bandwidth command must be applied on all interfaces or subinterfaces .
D. OoS policies must be enabled on all interfaces that will participate in the AutoOoS configuration.
E. An IP address must be configured on all low-bandwidth interfaces （768 kb/s or lower） that will participate in the AutoOoS configuration
F. An IP address must be configured on all interfaces that will participate in the AutoOoS configuratio

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多选题

Which two statements about the open and shared key wireless-authentication methods are true？（）

A. shared key authentication is considered more secure than open authentication
B. shared key authentication is considered less secure than open authentication
C. if the WEP keys do not match using the open authentication method， the client will not authenticate， associate， and transfer data
D. if the WEP keys do not match using the open authentication method， the client will still be able to authenticate and associate， but will not transfer data
E. if the WEP keys do not match using the open authentication method， the client will still be able to authenticate， associate， and transfer data

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多选题

Which two statements about the open and shared key wireless-authentication methods are true？（）

A. Shared key authentication is considered more secure than open authentication.
B. Shared key authentication is considered less secure than open authentication.
C. If the WEP keys do not match using the open authentication method， the client will not authenticate， associate， and transfer data.
D. If the WEP keys do not match using the open authentication method， the client will still be able to authenticate and associate， but will not transfer data.
E. If the WEP keys do not match using the open authentication method， the client will still be able to authenticate， associate， and transfer data.

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多选题

What are three of the functions that AutoQoS performs when it is configured on a switch？（）

A. synchronizes FIFO， PQ， CQ， and MDRR， with WFQ， CBWFQ， and LLQ
B. enables strict priority queuing for voice traffic， and weighted round robin queuing for data traffic
C. enables low latency queuing to ensure that voice traffic receives priority treatment
D. enforces a trust boundary on switch access ports and uplinks/downlinks
E. modifies queue sizes as well as queue weights where required
F. adjusts link speeds to adapt to QoS need

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多选题

What are two major sources of delay that can be managed by QoS in voice-enabled networks？（）

A. propagation delay
B. voice packet serialization delay
C. congested egress queues
D. header overhead
E. packets dropped because of CRC error

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单选题

Which two commands should be entered on a WLAN controller to remove any residual configuration？（）

A. Enter the clear controller command followed by the reload command.
B. Enter the clear controller command followed by the reset command.
C. Enter the clear controller command followed by the reset system command.
D. Enter the erase startup-config command followed by the reload command.
Enter the erase startup-config command followed by the reset command.
F. Enter the erase startup-config command followed by the reset system command.

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多选题

Which two statements about the QoS policy generation phase of the Cisco SDM QoS wizard are true？（）

A. the SDM QoS wizard will create two real-time traffic classes to handle VoIP， voice signaling， and video packets
B. the SDM QoS wizard will create three real-time traffic classes to handle VoIP， voice signaling， video， and video packets
C. the SDM QoS wizard will create four real-time traffic classes to handle VoIP， voice signaling， video， and video streaming packets
D. the SDM QoS wizard will create two business-critical traffic classes to handle transactional and network management packets
E. the SDM QoS wizard will create three business-critical traffic classes to handle transactional， network management， and routing packets
F. the SDM QoS wizard will create four business-critical traffic classes to handle transactional， network management， routing， and best-effort packet

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What are three problems with the tail drop mechanism of managing interface congestion？（）

Cisco provides two enhancements to 802.11 security which protect a WEP key from exploits. Which two technologies provide these security enhancements？ （）

What are three traffic descriptors that are used by the classification process to categorize packets that require special OoS handling？（）

Which three options are prerequisites to configuring Cisco AutoOoS？（）

Which two statements about the open and shared key wireless-authentication methods are true？（）

Which two statements about the open and shared key wireless-authentication methods are true？ （）

What are three of the functions that AutoQoS performs when it is configured on a switch？（）

What are two major sources of delay that can be managed by QoS in voice-enabled networks？（）

Which two commands should be entered on a WLAN controller to remove any residual configuration？（）

Which two statements about the QoS policy generation phase of the Cisco SDM QoS wizard are true？（）

Cisco provides two enhancements to 802.11 security which protect a WEP key from exploits. Which two technologies provide these security enhancements？（）

Which two statements about the open and shared key wireless-authentication methods are true？（）