单选题 请根据下图所示网络结构回答下列问题。
【正确答案】(1) ①152.19.63.192/30
②152.19.63.196/30
③152.19.63.o/29
④152.19.63.8/29
⑤152.19.0.0/22
⑥152.19.56.0/22
(2) router(config) #interdace e1
router(config-if) #ip access group 130 in
router(config-if) #ip access-group 130 out
(3) 255.255.255.240 152.19.58.129-142
255.255.255.240 152.19.58.145-158
255.255.255.224 152.19.58.161-190
【答案解析】[解析] (1) ①处包含152.19.63.193和152.19.63.194,对应的子网是152.19.63.192./30;
②处包含152.19.63.197和152.19.63.198,对应的子网是152.19.63.196/30;
③处包含152.19.63.1,152.19.63.2和152.19.63.3,对应的子网是152.19.63.0/29;
④处包含152.19.63.9,152.19.63.10和152.19.63.11,对应的子网是152.19.63.8/29;
⑤处包含152.19.0.1,152.19.1.1和152.19.2.1,对应的子网是152.19.0.0/22;
⑥152.19.56.1,152.19.57.1,152.19.58.1和152.19.59.1,对应的子网是152.19.63.0/29。
(2) 由于路由器已有访问控制列表,所以只需配置应用接口即可。
(3) 将152.19.58.128/26划分为三个子网,其中前两个子网分别能容纳10台主机,第三个子网能容纳20台主机,那么分成的三个子网分别容纳16,16,32台主机,因此分成的三个子网为:152.19.58.128~152.19.58.143,152.19.58.144~152.19.58.159,152.19.58.160~152.19.58.191,所以可用的IP地址段如答案所示。