The metric assigned to each network depends on the type of protocol.Some simple protocol, like RIP, treats each network as equals.The  (1)  of passing through each network is the same;it is one  (2)  count.So if a packet passes through 10 network to reach the destination, the total cost is 10 hop counts.Other protocols, such as OSPF, allow the administrator to assign a cost for passing through a network based on the type of service required.A  (3)  through a network can have different costs(metrics).For example, if maximum  (4)  is the desired type of service, a satellite link has a lower metric than a fiber-optic line.On the other hand, if minimum  (5)  is the desired type of service, a fiber-optic line has a lower metric than a satellite line.OSPF allow each router to have several routing table based on the required type of service.

1.[单选题]

The metric assigned to each network depends on the type of protocol.Some simple protocol, like RIP, treats each network as equals.The  (1)  of passing through each network is the same;it is one  (2)  count.So if a packet passes through 10 network to reach the destination, the total cost is 10 hop counts.Other protocols, such as OSPF, allow the administrator to assign a cost for passing through a network based on the type of service required.A  (3)  through a network can have different costsmetrics.For example, if maximum  (4)  is the desired type of service, a satellite link has a lower metric than a fiber-optic line.On the other hand, if minimum  (5)  is the desired type of service, a fiber-optic line has a lower metric than a satellite line.OSPF allow each router to have several routing table based on the required type of service.

  • A.process
  • B.hop
  • C.route
  • D.flow
2.[单选题]

The metric assigned to each network depends on the type of protocol.Some simple protocol, like RIP, treats each network as equals.The  (1)  of passing through each network is the same;it is one  (2)  count.So if a packet passes through 10 network to reach the destination, the total cost is 10 hop counts.Other protocols, such as OSPF, allow the administrator to assign a cost for passing through a network based on the type of service required.A  (3)  through a network can have different costsmetrics.For example, if maximum  (4)  is the desired type of service, a satellite link has a lower metric than a fiber-optic line.On the other hand, if minimum  (5)  is the desired type of service, a fiber-optic line has a lower metric than a satellite line.OSPF allow each router to have several routing table based on the required type of service.

  • A.packet
  • B.throughput
  • C.error
  • D.number
3.[单选题]

The metric assigned to each network depends on the type of protocol.Some simple protocol, like RIP, treats each network as equals.The  (1)  of passing through each network is the same;it is one  (2)  count.So if a packet passes through 10 network to reach the destination, the total cost is 10 hop counts.Other protocols, such as OSPF, allow the administrator to assign a cost for passing through a network based on the type of service required.A  (3)  through a network can have different costsmetrics.For example, if maximum  (4)  is the desired type of service, a satellite link has a lower metric than a fiber-optic line.On the other hand, if minimum  (5)  is the desired type of service, a fiber-optic line has a lower metric than a satellite line.OSPF allow each router to have several routing table based on the required type of service.

  • A.number
  • B.connection
  • C.connection
  • D.cost
4.[单选题]

The metric assigned to each network depends on the type of protocol.Some simple protocol, like RIP, treats each network as equals.The  (1)  of passing through each network is the same;it is one  (2)  count.So if a packet passes through 10 network to reach the destination, the total cost is 10 hop counts.Other protocols, such as OSPF, allow the administrator to assign a cost for passing through a network based on the type of service required.A  (3)  through a network can have different costsmetrics.For example, if maximum  (4)  is the desired type of service, a satellite link has a lower metric than a fiber-optic line.On the other hand, if minimum  (5)  is the desired type of service, a fiber-optic line has a lower metric than a satellite line.OSPF allow each router to have several routing table based on the required type of service.

  • A.delay
  • B.stream
  • C.packet
  • D.packet
5.[单选题]

The metric assigned to each network depends on the type of protocol.Some simple protocol, like RIP, treats each network as equals.The  (1)  of passing through each network is the same;it is one  (2)  count.So if a packet passes through 10 network to reach the destination, the total cost is 10 hop counts.Other protocols, such as OSPF, allow the administrator to assign a cost for passing through a network based on the type of service required.A  (3)  through a network can have different costsmetrics.For example, if maximum  (4)  is the desired type of service, a satellite link has a lower metric than a fiber-optic line.On the other hand, if minimum  (5)  is the desired type of service, a fiber-optic line has a lower metric than a satellite line.OSPF allow each router to have several routing table based on the required type of service.

  • A.flow
  • B.window
  • C.route
  • D.cost
参考答案: B,B,D,A,C
解题思路:赋予每一个网络的路由度量依赖于协议的类型。对于像RIP这样的简单协议,可以认为每个网络都是相同的,因而通过每一个网络的费用也都是相同的,其费用为1。所以,如果一个分组经过10个网络到达目标,则总的费用就是10跳。其他的协议,例如OSPF,允许网络管理员根据要求的服务类型赋予所通过的网络一个度量值。通过一个网络的路由可以具有不同的费用。例如,若期望的服务类型为最大吞吐率,则卫星链路比光纤线路的费用低。另一方面,如果期望的服务类型为最小延迟,则光纤线路比卫星线路的费用低。OSPF协议允许每一个路由器根据需要的服务类型设置几个不同的路由表。