单项选择题

在一台Cisco路由器上封禁ICMP协议,只允许215.192.40.16/28和202.204.28.0/24子网的ICMP数据包通过路由器,下列正确的access-list配置是______。

A.Router(config)#access-list 100 permit icmp 215.192.40.16 255.255.255.240 any
Router(config)#access-list 100 permit icmp 202.204.28.0 255.255.255.0 any
Router(config)#aceess-list 100 deny icmp any any
Router(config)#access-list 100 permit ip any any
Router(config)#
B.Router(config)#access-list 98 permit icmp 215.192.40.16 0.0.0.15 any
Router(config)#access-list 98 permit icmp 202.204.28.0 0.0.0.255 any
Router(config)#access-list 98 deny icmp any any
Router(config)#access-list 98 permit ip any any
Router(config)#
C.Router(config)#access-list 198 permit icmp 215.192.40.16 0.0.0.15 any
Router(config)#access-list 198 permit icmp 202.204.28.0 0.0.0.255 any
Router(config)#access-list 198 deny icmp any any
Router(config)#access—list 198 permit ip any any
Router(config)#
D.Router(config)#access-fist 198 permit icrnp 215.192.40.16 0.0.0.15 any
Router(config)#access-list 198 permit icmp 202.204.28.0 0.0.0.255 any
Router(config)#access-list 198 permit ip any any
Router(config)#access-list 198 deny icmp any any
Router(config)#
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单项选择题
如下图所示,某校园网用10Gbps的POS技术与CERNET相连,POS接121的帧格式是SDH,下列R1的POS3 0接口配置,正确的是()。

A.Router(config)#interface pos3/0
Router(config-if)#description To CERNET
Router(config-if)#bandwidth 10000
Router(config-if)#ip address 222.38.69.78 255.255.255.252
Router(config-if)#crc 64
Router(config-if)#pos framing sdh
Router(config-if)#no ip directed-broadcast
Router(config-if)#pos flag s1s0 2
Router(config-if)#no shutdown
Router(config-if)#exit
Router(config)#
B.Router(config)#interface pos3/0
Router(config-if)#description To CERNET
Router(config-if)#bandwidth 10000000
Router(config-if)#ip address 222.38.69.78 255.255.255.252
Router(config-if)#crc 16
Router(config-if)#pos framing sdh
Router(config-if)#no ip directed-broadcast
Router(config-if)#pos flag s1 s0 0
Router(config-if)#no shutdown
Router(config-if)#exit
Router(config)#
C.Router(config)#interface pos3/0
Router(config-if)#description To CERNET
Router(config-if)#bandwidth 10000000
Router(config-if)#ip address 222.38.69.78 0.0.0.3
Router(config-if)#crc 32
Router(config-if)#pos framing sdh
Router(config-if)#no ip directed-broadcast
Router(config-if)#pos flag s1 s0 2
Router(config-if)#no shutdown
Router(config-if)#exit
Router(config)#
D.Router(config)#interface pos3/0
Router(config-if)#description To CERNET
Router(config-if)#bandwidth 10000000
Router(config-if)#ip address 222.38.69.78 255.255.255.252
Router(config-if)#crc 16
Router(config-if)#pos framing sdh
Router(config-if)#no ip directed-broadcast
Router(config-if)#pos flag s1 s0 2
Router(config-if)#no shutdown
Router(config-if)#exit
Router(config)#