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