内网可以访问外网，外网不能访问内网！（ACL）
1.搭建的拓扑图ide
2.配置命令：测试
R7(config)#ip access-list extended ref_gjpflex
R7(config-ext-nacl)#permit ip 192.168.1.0 0.0.0.255 any reflect ref_gjp1lua
R7(config-ext-nacl)#exitblog
R7(config)#ip access-list extended ref_gjp2ip
R7(config-ext-nacl)#evaluate ref_gjp1get
R7(config-ext-nacl)#exitit
R7(config)#int f1/0class
R7(config-if)#ip access-group ref_gjp outcli
R7(config-if)#ip access-group ref_gjp2 in
R7(config-if)#end
3. 配置截图：
测试:
R7#show ip access-list
Extended IP access list ref_gjp
10 permit ip 192.168.1.0 0.0.0.255 any reflect ref_gjp1 (41 matches)
Reflexive IP access list ref_gjp1
permit icmp host 192.168.101.128 host 192.168.1.10 (14 matches) (time left 240)
Extended IP access list ref_gjp2
10 evaluate ref_gjp1
(若有误，请多多指教！)