The ATM networks have been widely adopted as the backbone networks. LANE is adopted by the MPOA protocol for the intra-IASG communication. In LANE, the edge devices have become performance bottlenecks. The ATM-attached hosts and the dual-stack hosts, which run the LAN emulation protocol on them, have also encountered performance bottlenecks. In this paper, we will focus on how to improve the intra-IASG communication. We propose a modified MPOA protocol. The details of changes and flows are explained. The modified MPOA protocol improves the performance of the intra-IASG communication, simplifies the process of establishing a connection, eases the loads of both the LES and the BUS, increases the efficiency of the edge devices and the dual-stack hosts, and allows the ATM-attached hosts which run the IPOA protocol to be part of the MPOA protocol.