• In the following essay, each blank has four choices. Choose the best answer and write down on the answer sheet.In low-speed network,it is usually adequate to wait for congestion to occur and then react to it by telling the source of packets to slow down. In high-speed networks, this approach often works poorly, because in the (71) between sending the notification and notification arriving at the source, thousands of additional (72) may arrive. In ATM network , a major tool for preventing (73) is (74) control. When a host wants a new virtual (75) ,it must describe the traffic to be offered and the service expected.

　　(71) A interval B time C slot D delay

　　(72) A packets B cells C message D files

　　(73) A collision B congestion C drop D delay

　　(74) A flow B admission C traffic D time

　　(75) A path B rout C circuit D way

　　答案：(71) A (72)A (73)B(74)B(75)C

　　網絡工程師模擬試題下(2)

　　試題一：(15分)

　　某網絡的連接于圖1所示，其路由器的配置如下。

　　【路由器Router的部分配置信息】

　　Router(config)#interface fastEthernet1/0.1

　　Router(config-subif)#encapsulation isl 11 (1)

　　Router(config-subif)#ip address 10.1.1.1 255.255.255.0 (2)

　　Router(config-subif)#exit

　　Router(config)# interface fastEthernet1/0.2

　　Router(config- subif)#encapsulation isl 12

　　Router(config- subif)#ip address 10.1.2.1 255.255.255.0

　　Router(config-subif)#exit

　　Router(config)# interface fastEthernet1/0.3

　　Router(config- subif)#encapsulation isl 13

　　Router(config- subif)#ip address 10.1.3.1 255.255.255.0

　　Router(config-subif)#exit

　　Router(config)# ip routing (3)

　　【交換機Switch1的部分配置信息】

　　Switch1(config)#vlan database (4)

　　Switch1(vlan)#vlan 11 (5)

　　Switch1(vlan)#vlan 12

　　Switch1(vlan)#vlan 13

　　Switch1(vlan)#exit

　　Switch1(config)#interface fastEthernet0/0

　　Switch1(config-if)#switchport mode trunk(6)

　　Switch1(config-if)#switchport trunk allowed all (7)

　　Switch1(config-if)#exit

　　Switch1(config)#interface fastEthernet0/1

　　Switch1(config-if)#switchport mode trunk

　　Switch1(config-if)#switchport trunk allowed all

　　Switch1(config-if)#exit

　　Switch1(config)#interface fastEthernet0/2

　　Switch1(config-if)#switchport mode trunk

　　Switch1(config-if)#switchport trunk allowed all

　　Switch1(config-if)#exit

　　【問題1】

　　解釋畫線部分的意義。(7分)

　　答： (1)將vlan11 的接口封裝為ISL(2)設置vlan1的默認網關為10.1.1.1 (3)啟動ip轉發 (4)定義vlan (5)定義一個vlan 為11 (6)接口設置為trunk模式 (7)允許所有vlan信息在trunk中傳遞

　　【問題2】

　　給出三個vlan各自的IP地址范圍。(3)

　　vlan11 10.1.1.0/24 vlan12 10.1.2.0/24 vlan13 10.1.3.0/24