試題詳解

21封禁ICMP协议，只转发212.78.170.166/27所在子网的所有站点的ICMP数据包，正确的access-list配置是
(A) Router(config #access-list 110 permit icmp 212.78.170.166 0.0.0.0 any 　　Router(config #access-list 110 deny icmp any any 　　　　Router(config #access-list 110 permit ip any any
(B) Router(config #access-list 110 permit icmp 212.78.170.0 255.255.255.224 any 　　　 Router(config #access-list 110 permit ip any any 　　　 Router(config #access-list 110 deny icmp any any
(C) Router(config #access-list 110 perimt icmp 212.78.170.0 0.0.0.255 any 　　Router(config #access-list 110 deny icmp any any 　　　　Router(config #access-list 110 permit ip any any
(D) Router(config #access-list 110 permit icmp 212.78.170.160 0.0.0.31 any 　　Router(config #access-list 110 deny icmp any any 　　　　Router(config #access-list 110 permit ip any any