Router(config)#access-list 1 permit any

Router(config)#interface fastEthernet 0/0
Router(config-if)#ip address 192.168.0.111 255.255.255.0
Router(config-if)#no shutdown
Router(config-if)#ip nat outside
Router(config)#interface fastEthernet 0/1
Router(config-if)#ip address 192.168.11.1 255.255.255.0
Router(config-if)#no shutdown
Router(config-if)#ip nat inside
Router(config)#access-list 1 permit any
Router(config)#ip nat pool 123 192.168.0.111 192.168.0.111 netmask 255.255.255.0
Router(config)#ip nat inside source list 1 pool 123 overload
Router(config)#ip route 0.0.0.0 0.0.0.0 192.168.0.254(目标地址）