To resolve the scalability problem in the existing Internet, there are many researches proposing the idea of separating the Internet into two independent evolving spaces, called the access and core network, respectively. In the new network environment, the existing routing protocols require additional mechanisms to provide accurate reachability information. In this paper, based on the in-depth study of the existing routing protocols, we design and implement the extensions to the existing routing protocols to support the separation of the two spaces.