In classical IPOA, the communication of two users between local Asynchronous Transfer Mode(ATM) ports needs a VCC, however, it is not an elegant solution to the ATM access equipments design when the performance of the whole system is considered. Thus, we investigate the way to provide the improved IPOA protocol that uses switching way in local ports. And it is fully compatible with the CIPOA by using the same protocol for ARP and IP forwarding. In addition, we also present the design of one 10/100 Mbit/s auto adaptive IPOA client board with local switch ability idea and CAM mechanism for our project.