要求整个网络可以访问互联网，使用NAT转换
2017年6月30日
14:13
1、用Internet路由器模仿公网路由，配置如下
Router>enable
Router#config t
Enter configurationcommands, one per line. End with CNTL/Z.
Router(config)#inters1/0
Router(config-if)#ipadd 1.1.1.1 255.255.255.0
Router(config-if)#clockrate 6400
Router(config-if)#noshutdown
模拟公网路由器配置完成
2、配置企业路由器
配置连接公网的接口IP地址把接口定义为outside
Router>enable
Router#config t
Enter configurationcommands, one per line. End with CNTL/Z.
Router(config)#inters1/1
Router(config-if)#ipadd 1.1.1.2 255.255.255.0
Router(config-if)#noshutdown
Router(config-if)#
%LINK-5-CHANGED:Interface Serial1/1, changed state to up
%LINEPROTO-5-UPDOWN:Line protocol on Interface Serial1/1, changed state to up
Router(config-if)#ip nat outside
配置连接三层交换机接口IP地址把接口定义为inside
Router(config)#interf0/0
Router(config-if)#ipadd 172.16.1.2 255.255.255.0
Router(config-if)#noshutdown
Router(config-if)#
%LINK-5-CHANGED:Interface FastEthernet0/0, changed state to up
%LINEPROTO-5-UPDOWN:Line protocol on Interface FastEthernet0/0, changed state to up
Router(config-if)#ip nat inside
配置acl访问控制列表，不配置无法访问通过路由访问公网（这里特别重要）如果不把所有要
允许访问公网的网段配置成允许访问的状态，路由器就会阻止这些网段访问公网
Router(config)#access-list10 permit 192.168.1.0 0.0.0.255
Router(config)#access-list10 permit 192.168.2.0 0.0.0.255
Router(config)#access-list10 permit 192.168.3.0 0.0.0.255
配置NAT地址转换
Router(config)#ip natinside source list 10 interface s1/1 overload
3、配置三层交换机
创建一个vlan5用来配置与路由连接的地址，并把f0/1划入vlan5
Switch(config)#vlan 5
Switch(config)#interf0/1
Switch(config-if)#swit
Switch(config-if)#switchportmo
Switch(config-if)#switchportmode acc
Switch(config-if)#switchportmode access
Switch(config-if)#swac
Switch(config-if)#swaccess vlan 5
配置vlan地址
Switch(config-if)#intervlan 5
Switch(config-if)#
%LINK-5-CHANGED:Interface Vlan5, changed state to up
%LINEPROTO-5-UPDOWN:Line protocol on Interface Vlan5, changed state to up
Switch(config-if)#ipadd 172.16.1.1 255.255.255.0
Switch(config-if)#noshutdown
把其它vlan也配置好
配置Vlan2
Switch(config)#interf0/2
Switch(config-if)#swmo acc
Switch(config-if)#swacc vlan 2
Switch(config-if)#intervlan 2
Switch(config-if)#
%LINK-5-CHANGED:Interface Vlan2, changed state to up
%LINEPROTO-5-UPDOWN:Line protocol on Interface Vlan2, changed state to up
Switch(config-if)#ipadd 192.168.1.254 255.255.255.0
Switch(config-if)#noshut
Switch(config-if)#
配置Vlan3
Switch(config-if)#noshut
Switch(config-if)#interf0/3
Switch(config-if)#swmo acc
Switch(config-if)#swacc vlan 3
Switch(config-if)#intervlan 3
Switch(config-if)#
%LINK-5-CHANGED:Interface Vlan3, changed state to up
%LINEPROTO-5-UPDOWN:Line protocol on Interface Vlan3, changed state to up
Switch(config-if)#ipadd 192.168.2.254 255.255.255.0
配置Vlan4
Switch(config-if)#interf0/4
Switch(config-if)#swmo acc
Switch(config-if)#swacc vlan 4
Switch(config-if)#intervlan 4
Switch(config-if)#
%LINK-5-CHANGED:Interface Vlan4, changed state to up
%LINEPROTO-5-UPDOWN:Line protocol on Interface Vlan4, changed state to up
Switch(config-if)#ipadd 192.168.3.254 255.255.255.0
配置DHCP服务器
配置vlan2DHCP服务器
Switch(config)#ipdhcp pool vlan2
Switch(dhcp-config)#default-router192.168.1.254
Switch(dhcp-config)#dns-server1.1.1.1
Switch(dhcp-config)#network192.168.1.0 255.255.255.0
Switch(dhcp-config)#exit
配置vlan3DHCP服务器
Switch(config)#ipdhcp pool vlan3
Switch(dhcp-config)#default-router192.168.2.254
Switch(dhcp-config)#dns-server2.2.2.2
Switch(dhcp-config)#network192.168.2.0 255.255.255.0
Switch(dhcp-config)#exit
配置vlan4DHCP服务器
Switch(config)#ipdhcp pool vlan4
Switch(dhcp-config)#default-router192.168.3.254
Switch(dhcp-config)#dns-server3.3.3.3
Switch(dhcp-config)#network192.168.3.0 255.255.255.0
Switch(dhcp-config)#exit
开启三层交换机路由功能
ip routing
到这里所有的vlan间的电脑已经能够相互ping通了，但是还是不能访问互联网，因为路由还没有
配置完成