定义一个用于封禁ICMP协议而只允许转发166.129.130.0/24子网的ICMP数据包的访问控制列表，Cisco路

A．

B．

C．

D．

A.A

B.B

C.C

D.D

A.access-list 198 permit icmp 166．129．130．0 255．255．255．0 anyaccess-list 198 deny iemp any anyaccess-list 198 permit ip any any

B.access-list 198 permit icmp 166．129．130．0 0．0．0．255 anyaccess-list 198 deny iemp any anyaccess-list 198 permit ip any any

C.access-list 99 permit icmp 166．129．130．0 0．0．0．255 anyaccess-list 99 deny iemp any anyaccess-list 99 permit ip any any

D.access-list 100 permit icmp 166．129．130．0 0．0．0．255 anyaccess-list 100 permit ip any anyaccess-list 100 deny icmp any any

A) access-list 198 permit icmp 166.129.130.0 255.255.255.0 any

access-list 198 deny icmp any any

access-list 198 permit ip any any

B) access-list 198 permit icmp 166.129.130.0 0.0.0 255 any

access-list 198 deny icmp any any

access-list 198 permit ip any any

C) access-list 99 permit icmp 166.129.130.0 0.0.0 255 any

access-list 99 deny icmp any any

access-list 99 permit ip any any

D) access-list 100 permit icmp 166.129.130.0 0.0.0 255 any

access-list 100 pernut ip any any

access-list 100 deny icmp any any

A．

B．

C．

D．

A.A

B.B

C.C

D.D

A．access-list 90 deny icmp l68．27．95．0 255．255．255．0 any access-list 90 deny icmp any anyaccess—list 90 permit ip any any

B．access-list l00 permit icmp l68．27．95．0 0．0．0．255 any access-list l00 permit ip any any

C．access—list l l o permit icmp l68．27．95．0 255．255．255．0 any access—list l lo deny icmp any any

D．access-list l20 permit icmp l68．27．95．0 0．0．0．255 any access—list l20 deny icmp any any access—list l20 permit ip any any

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 iemp 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

A、ICMP封装在IP数据报的数据部分

B、ICMP消息的传输是可靠的

C、一般不把ICMP作为高层协议，而只作为IP必需的一个部分。

D、ICMP一般用于在Internet上进行差错报告

A.启用安全组，拒绝“公网入”的ICMP协议

B.启用ECS内操作系统的防火墙，拒绝“公网入”的ICMP协议

C.先将ECS IP解析到一个不常用的四级域名，然后将对外推广的域名通过CNAME指向以上四级域名

D.启用安全组，只允许公网TCP 80端口和25端口访问