路由器发布服务器

局域网口地址：10.18.100.1 子网掩码：255.255.0.0
合法IP地址：211.82.220.80----211.82.220.87 子网掩码：255.255.255.248
连接ISP的端口ethernet1的IP地址为211.82.100.81  子网掩码：255.255.255.248

要求：局域网的计算机可以访问internet并且在internet 中提供web,e-mail,ftp,media等到四种服务。

interface fastethernet 0/0
ip address 10.18.100.1 255.255.0.0
dupex auto
speed auto
ip nat inside

interface fastethernet 0/1
ip address 211.82.220.81 255.255.255.248
duplex auto
speed auto
ip nat outside

ip nat pool every 211.82.220.86  211.82.220.86 netmask 255.255.255.248
定义合法的地址池
access-list 1 permit 10.18.101.0    0.0.0.255
access-list 1 permit 10.18.102.0    0.0.0.255
access-list 1 permit 10.18.103.0    0.0.0.255
access-list 1 permit 10.18.104.0    0.0.0.255
ip nat inside source list1 pool every overload
静态转换：
ip nat inside source static 10.18.100.10    211.82.220.82
ip nat inside source static 10.18.100.11    211.82.220.83
ip nat inside source static 10.18.100.12    211.82.220.84
ip nat inside source static 10.18.100.13    211.82.220.85

案例四：tcp/udp nat端口映射
网络环境：
局域网采用10M光纤以城域网方式接入internet 
路由器拥有2个10/100M自适应端口的cisco 2611
内部地址：192.168.1.1-----192.168.1.251
局域网端口ethernet0的ip 192.168.1.1 subnet: 255.255.255.0
网络合法地址：211.82.220.128----211.82.220.131
连接ISP的地址：211.82.220.129 子网掩码：255.255.255.252
可用于转换的地址：211.82.220.130

interface fastethernet 0/0
ip address 192.168.1.1 255.255.255.0
duplex auto
speed auto
ip nat inside

interface ethernet 0/1
ip address 211.82.220.129 255.255.255.252
duplex auto
speed auto
ip nat outside

ip nat pool everyone 211.82.220.130  211.82.220.130 netmask 255.255.255.252
access-list 1 permit 192.168.1.0    0.0.0.255
ip nat inside source list1  pool everyone overload

ip nat inside source list1 interface fastethernet 0/1 overload(端口复用直接采用f0/1的地址)
ip nat inside source static tcp 192.168.1.11 80  211.82.220.130 80
ip nat inside source static tcp 192.168.1.12 21  211.82.220.130 21