Internet has evolved from an educational network into a public business and information infrastructure. The monitoring and analysis of the routing plane, which lies in the heart of Internet, has significant theoretic and practical implications. Internet routing architecture is generally partitioned into intra-domain routing and inter-domain routing. Because inter-domain and intra-domain routing protocols are often interdependent, problems with one protocol can affect the performance of the other. Much work has been done with Internet routing monitoring and analysis, and it is helpful for operators to recover their networks from routing disasters. However, most of previous work is around a single routing protocol, which performs poorly in providing comprehensive routing view and protocol interaction analysis. Motivated by this, the intra-domain and inter-domain routing correlation analysis technique is explored in this paper. The authors first propose an Internet routing topology model (IRTM), then present a key monitoring algorithm, and finally successfully implement Internet routing monitoring system (IRMS). IRMS, which is based on OSPF and BGP monitoring, provides correlated routing analyses including full-scale routing topology construction and protocol interaction analysis. IRMS has been applied to routing monitoring in a regional ISP network for one month, and the results show that IRMS provides facilities for network operators going deep into routing monitoring.