NAT地址转换
由于IP地址有限，又分为私网和公网地址，为了节省IP地址，私网地址可与公网地址重复，但不能出现在公网当中，当需要与公网数据通信时，则出现了一种地址转换技术，即NAT地址转换，通过在路由器上的配置实现。数据出路由器转换的是源IP地址，数据进路由器转换的是目标IP地址。
NAT类型
- 静态NAT：一个私网IP地址对应一个公网IP地址，并未节省IP地址
- 动态NAT：多个私网IP地址对应多个公网IP地址，并不节省IP地址
- EasyIP：多个私网IP地址对应外网口公网IP地址，最节省IP地址
- NAT Server（映射）如下图：
实验拓扑
PC1采用静态NAT地址转换，在R1上配置，进入外网端口，配置如下：
[R1-GigabitEthernet0/0/0]nat static global 8.8.8.8 inside 192.168.10.10
PC2和PC4采用动态NAT地址转换，建立地址池1，在池中获取公网IP，配置如下：
[R1]nat address-group 1 212.0.0.100 212.0.0.200
[R1]acl 2000
[R1-acl-basic-2000]rule permit source 192.168.20.0 0.0.0.255
[R1-acl-basic-2000]rule permit source 11.0.0.0 0.0.0.255
[R1-acl-basic-2000]q
[R1]int g0/0/0
[R1-GigabitEthernet0/0/0]nat outbound 2000 address-group 1 no-pat
PC3采用EasyIP，配置如下：
[R1]acl 3000
[R1-acl-adv-3000]rule permit ip source 192.168.30.0 0.0.0.255
[R1-acl-adv-3000]q
[R1]int g0/0/0
[R1-GigabitEthernet0/0/0]nat outbound 3000
服务器上用NAT sever
[R1-GigabitEthernet0/0/0]nat server protocol tcp global 9.9.9.9 www inside 192.168.10.100 www
所有配置如下图所示：
R1
[R1]int g0/0/1
[R1-GigabitEthernet0/0/1]ip add 11.0.0.1 24
[R1-GigabitEthernet0/0/1]int g0/0/0
[R1-GigabitEthernet0/0/0]ip add 12.0.0.1 24
[R1-GigabitEthernet0/0/0]q
[R1]ip route-static 192.168.10.0 24 11.0.0.2
[R1]ip route-static 192.168.20.0 24 11.0.0.2
[R1]ip route-static 192.168.30.0 24 11.0.0.2
[R1]ip route-static 0.0.0.0 0.0.0.0 12.0.0.2
[R1]int g0/0/0
[R1-GigabitEthernet0/0/0]nat st [R1-GigabitEthernet0/0/0]nat static global 8.8.8.8 inside 192.168.10.10
[R1-GigabitEthernet0/0/0]q
[R1]nat address-group 1 212.0.0.100 212.0.0.200
[R1]acl 2000
[R1-acl-basic-2000]rule p
[R1-acl-basic-2000]rule permit s
[R1-acl-basic-2000]rule permit source 192.168.20.0 0.0.0.255
[R1-acl-basic-2000]rule permit source 11.0.0.0 0.0.0.255
[R1-acl-basic-2000]q
[R1]int g0/0/0
[R1-GigabitEthernet0/0/0]nat outbound 2000 address-group 1 no-pat
[R1-GigabitEthernet0/0/0]q
[R1]acl 3000
[R1-acl-adv-3000]rule permit ip source 192.168.30.0 0.0.0.255
[R1-acl-adv-3000]q
[R1]int g0/0/0
[R1-GigabitEthernet0/0/0]nat outbound 3000
[R1-GigabitEthernet0/0/0]nat server protocol tcp global 9.9.9.9 www inside 192.168.10.100 www
R2
[R2]int g0/0/0
[R2-GigabitEthernet0/0/0]ip add 12.0.0.2 24
[R2-GigabitEthernet0/0/0]int g0/0/1
[R2-GigabitEthernet0/0/1]ip add 13.0.0.1 24
[R2-GigabitEthernet0/0/1]q
[R2]int loop 0
[R2-LoopBack0]ip add 114.114.114.114 32
[R2]ip route-static 11.0.0.0 24 12.0.0.1
[R2]ip route-static 192.168.10.0 24 12.0.0.1
[R2]ip route-static 192.168.20.0 24 12.0.0.1
[R2]ip route-static 192.168.30.0 24 12.0.0.1
[R2]ip route-static 8.8.8.8 32 12.0.0.1
[R2]ip route-static 9.9.9.9 32 12.0.0.1
[R2]ip route-static 212.0.0.0 24 12.0.0.1
SW1
[SW1]int g0/0/1
[SW1-GigabitEthernet0/0/1]p l a
[SW1-GigabitEthernet0/0/1]p d v 40
[SW1-GigabitEthernet0/0/1]int g0/0/2
[SW1-GigabitEthernet0/0/2]p l a
[SW1-GigabitEthernet0/0/2]p d v 10
[SW1-GigabitEthernet0/0/2]int g0/0/3
[SW1-GigabitEthernet0/0/3]p l a
[SW1-GigabitEthernet0/0/3]p d v 20
[SW1-GigabitEthernet0/0/3]int g0/0/4
[SW1-GigabitEthernet0/0/4]p l a
[SW1-GigabitEthernet0/0/4]p d v 30
[SW1-GigabitEthernet0/0/4]int g0/0/5
[SW1-GigabitEthernet0/0/5]p l a
[SW1-GigabitEthernet0/0/5]p d v 20
[SW1-GigabitEthernet0/0/5]int g0/0/6
[SW1-GigabitEthernet0/0/6]p l a
[SW1-GigabitEthernet0/0/6]p de v 10
[SW1-GigabitEthernet0/0/6]q
[SW1]int vlanif 10
[SW1-Vlanif10]ip add 192.168.10.1 24
[SW1-Vlanif10]int vlanif 20
[SW1-Vlanif20]ip add 192.168.20.1 24
[SW1-Vlanif20]int vlanif 30
[SW1-Vlanif30]ip add 192.168.30.1 24
[SW1]ip route-static 0.0.0.0 0.0.0.0 11.0.0.1
[SW1]int vlanif 40
[SW1-Vlanif40]ip add 11.0.0.2 24