In this paper we present IPas++, a novel accountable and scalable Internet Protocol for future internet. IPas++ decomposes the Internet into several accountability realms (ARs) with self-certifying identifiers and then separates edge ARs (EARs) from core ARs (CARs) along the identifier/locator separation line. Based on these, IPas++ uses a two level hierarchical address structure and an inherently accountable inter-AR routing. IPas++ also builds a reliable EAR-to-CAR mapping distribution system by extending BGP. We show that IPas++ is able to work across heterogeneous ARs and discuss how IPas++ meets the requirements of future internet including security and scalability. We also analyze the performance, deployment and weaknesses of IPas++. Our preliminary experiments indicate that IPas++ is quite an ideal proposal.