CCNA、CCNP、CCIE模拟试题

23.You are the network administrator at ABC.com. ABC has a switched network.
 You want to control the designation of the spanning-tree root bridge in the ABC network. What should you do?

A. By enabling uplink-fast on the ports of the desired switch.
B. By lowering the bridge priority on the desired switch.
C. By setting a lower MAC address on the designated switch.
D. By raising the bridge ID on one switch.

   24.You are a technician at ABC. You receive a report from several ABC users who
 complain that they get slow responses when sending and receiving email, especially
 when browsing the Internet. You investigate the complaint by checking the output
 of a ping command issued from her computer and find that it indicates intermitted
 success and failures messages, when attempting to contact the email server. A 
tracert to the corporate Internet gateway router shows high latency and occasional
 time out messages.
What would be the most effective troubleshooting approach if you are to determine
 the cause of the slow response time?

A. Bottom-up approach
B. Random access approach
C. Divide and conquer approach
D. Top-down approach
E. Top-down rule-out approach

    25.You are a technician at ABC.com. Your newly appointed ABC trainee wants to 
know what features make OSPF more suitable than RP in large network installations.
 What would your reply be? (Choose all that apply.)

A. Diffusing Update Algorithm
B. No hop count limitation
C. Higher routing update overhead
D. Faster convergence
E. Lower routing update overhead

    CCIE

    26.You are the network administrator at ABC. You are troubleshooting a network
 problem. You want to trace the route to a Unix workstation that you want to reach
 through the Internet. However, Traceroute does not work.
Currently, there is an inbound access-list applied to the serial interface on 
Router 1. An entry in the access-list states "access-list 101 permit tcp any any". 
What access-list

entry may you need to be added to the access-list in order to get traceroute to 
work?

A. access-list 101 permit udp any any
B. access-list 101 permit icmp any any time-exceeded access-list 101 permit icmp 
any any port-unreachable
C. access-list 101 permit icmp any any time-exceeded access-list 101 permit icmp 
any any net-unreachable
D. access-list 101 permit icmp any any echo access-list 101 permit icmp any anynet-unreachable
E. access-list 101 permit udp any any access-list 101 permit icmp any any 
protocol-unreachable

    27.What does the BGP backdoor command do?

A. It changes the distance of an iBGP route to 20.
B. It changes the distance of an eBGP route to 200.
C. It changes the distance of an IGP route to 20.
D. It does not effect any changes in distance of the route.
E. It changes the distance of an IGRP route to 200.

    28.Which of the following DNS resource records is not valid?

A. NS
B. PTR
C. MX
D. FQDN
E. A

    29.Which of the following features is provided by RIP v2 that were previously
 not possible with RIP v1? (Choose all that apply.)

A. Classless routing and split-horizon.
B. Poison reverse and updating to multicast addresses.
C. Poison reverse and classless routing.
D. Classless routing and updating to multicast addresses.
E. Route tag and classless routing.

    30.Which of the following statements is valid when taking Custom Queuing into
 account?

A. Custom queuing has the ability to restrict a particular type of traffic to a
 given bandwidth not matter what is load is like on that link.