configure terminal interface GigabitEthernet0/0 ip address 203.0.113.17 255.255.255.248 ip nat outside no shutdown exit interface GigabitEthernet0/1 ip nat inside no shutdown exit interface GigabitEthernet0/2 ip nat inside no shutdown exit access-list 100 permit ip 192.168.1.0 0.0.0.255 any access-list 100 permit ip 192.168.2.0 0.0.0.255 any access-list 100 permit ip 192.168.23.0 0.0.0.255 any ip nat inside source list 100 interface GigabitEthernet0/0 overload