试题1

Border Gateway Protocol(BGP) is inter-autonomous system  (1)  protocol. BGP is based on a routing method called path vector routing. Distance vector routing is not a good candidate for inter-autonomous system routing because there are occasions on which the route with the smallest  (2)  count is not the preferred route. For example, we may not want a packet through an autonomous system that is not secure even though it is shortest route. Also, distance vector routing is unstable due to the fact that the routers announce only the number of hop counts to the destination without defining the path that leads to that  (3)  . A router that receives a distance vector advertisement packet may be fooled if the shortest path is actually calculated through the receiving router itself. Link  (4)  routing is also not a good candidate for inter-autonomous system routing because an internet is usually too big for this routing method. To use link state routing for the whole internet would require each router to have a huge link state database. It would also take a long time for each router to calculate its routing  (5)  using the Dijkstra algorism.
（1）A、routing
B、switching
C、transmitting
D、receiving
（2）A、path
B、hop
C、route
D、packet
（3）A、connection
B、window
C、source
D、destination
（4）A、status
B、search
C、state
D、research
（5）A、table
B、state
C、metric
D、cost

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试题2

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试题3

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试题4

下面几个网络管理工具的描述中，错误的是  （ ）  。
A、netstat 可用于显示IP、TCP、UDP、ICMP等协议的统计数据
B、sniffer 能够使网络接口处于杂收模式，从而可截获网络上传输的分组
C、winipcfg 采用MS-DOS工作方式显示网络适配器和主机的有关信息
D、tracert 可以发现数据包到达目标主机所经过的路由器和到达时间

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试题5

Networks can be interconnected by different devices.In the physical layer,  networks can be connected by  （1）  or hubs, which just move the bits from one network to an identical network. One layer up we find bridges and switches, which operate at data link layer. They can accept  （2） , examine the MAC address, and forward the frames to a different network while doing minor protocol translation in the process. In the network layer, we have routers that can connect two networks, If two networks have  （3）  network layer, the router may be able to translate between the packer formats. In the transport layer we find transport gateway, which can interface between two transport connections.Finally, in the application layer, application gateways translate message  （4） . As an example, gateways between Internet e-mail and X.400 e-mail must  （5）  the e-mail message and change various header fields.
（1）A、repeaters
B、relays
C、connectors
D、modems
（2）A、frames
B、packets
C、packages
D、cells
（3）A、special
B、dependent
C、similar
D、dissimilar
（4）A、syntax
B、semantics
C、language
D、format
（5）A、analyze
B、parse
C、delete
D、create

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试题6

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试题7

以下关于X.25网络的描述中，正确的是 （ ） 。
A、X.25的网络层提供无连接的服务
B、X.25的网络丢失帧时，通过检查帧顺序号重传丢失帧
C、X.25的网络使用LAP-D作为传输控制协议
D、X.25的网络采用多路复用技术，帧中的各个时槽被预先分配给不同的终端

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试题8

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试题9

在相隔400Km的两地间通过电缆以4800b/s的速率传送3000比特长的数据包，从开始发送到接收完数据需要的时间是  ( )  。
A、480ms
B、607ms
C、612ms
D、627ms

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试题10

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