Cisco NAT 的配置例子

    !
    version 12.0
    service timestamps debug uptime
    service timestamps log uptime
    no service password-encryption
    !
    hostname nat-r1
    !
    enable secret 5 $1$FEQr$INhRecYBeCb.UqTQ3b9mY0
    !
    ip subnet-zero
    !
    !
    !
    !
    interface Ethernet0
    ip address 172.18.150.150 255.255.0.0
    no ip directed-broadcast
    ip nat inside /* 定义此为网络的内部端口 */
    !
    interface Serial0
    ip address 192.1.1.161 255.255.255.252
    no ip directed-broadcast
    ip nat outside /* 定义此为网络的外部端口 */

    no ip mroute-cache
    no fair-queue
    !
    interface Serial1
    no ip address
    no ip directed-broadcast
    shutdown
    ! /* 定义从ISP那里申请到的IP在企业内部的分配策阅 */
    ip nat pool tech 192.1.1.100 192.1.1.120 netmask 255.255.255.0
    ip nat pool deve 192.1.1.121 192.1.1.150 netmask 255.255.255.0
    ip nat pool manager 192.1.1.180 192.1.1.200 netmask 255.255.255.0
    ip nat pool soft-1 192.1.1.170 192.1.1.179 netmask 255.255.255.0
    ip nat pool soft-2 192.1.1.151 192.1.1.159 netmask 255.255.255.0
    ip nat pool temp-user 192.1.1.160 192.1.1.160 netmask 255.255.255.0
    /* 将访问列表与地址池对应，以下为动态地址转换*/
    ip nat inside source list 1 pool tech
    ip nat inside source list 2 pool deve
    ip nat inside source list 3 pool manager
    ip nat inside source list 4 pool soft-1
    ip nat inside source list 5 pool soft-2
    /* 将访问列表与地址池对应，以下为复用动态地址转换*/
    ip nat inside source list 6 pool temp-user overload
    /* 将访问列表与地址池对应，以下为静态地址转换*/
    ip nat inside source static 172.18.100.168 192.1.1.168
    ip nat inside source static 172.18.100.169 192.1.1.169
    ip classless
    ip route 0.0.0.0 0.0.0.0 Serial0 /* 设置一个缺省路由 */
    !

    /* 内部网访问地址表，他指出内部网络能访问外部网的地址段，
    分别定义是为了对应
    不同的地址池 */
    access-list 1 permit 172.18.107.0 0.0.0.255
    access-list 2 permit 172.18.101.0 0.0.0.255
    access-list 3 permit 172.18.108.0 0.0.0.255
    access-list 4 permit 172.18.103.0 0.0.0.255
    access-list 4 permit 172.18.102.0 0.0.0.255
    access-list 4 permit 172.18.104.0 0.0.0.255
    access-list 5 permit 172.18.105.0 0.0.0.255
    access-list 5 permit 172.18.106.0 0.0.0.255
    access-list 6 permit 172.18.111.0 0.0.0.255
    !
    line con 0
    transport input none
    line 1 16
    line aux 0
    line vty 0 4
    login
    !
    end