连外网

ena
conf t
int fo/0
ip add +公网地址+子网掩码
ip nat ouside
no shut
int fo/1
ip add +内网地址+子网掩码
ip nat inside
no shut
ip route 0.0.0.0 0.0.0.0 +公网网关地址
access-list 1 premit+内网网关地址+0.0.0.255
ip nat in source list 1 int fo/0 overload
输完检测网络

原文：http://blog.csdn.net/shienquan/article/details/40260217