SUMMARYAn IRR (Internet Routing Registry) is a database for registering routes on the Internet or AS numbers. However, there are indications that the data recorded in the IRRs are not correctly updated and do not correctly reflect the actual situation on the Internet. Accordingly, this research evaluated (1) the consistency of IRRs with actual Internet routing information and (2) differences in consistency among IRRs. Specifically, route objects in an IRR and actual BGP routing information were compared using Exact Match and Best Match methods. As a result it became clear that the Exact Match registration rate was low, while the Best Match registration rate was high. Furthermore, an evaluation of the utility of the Best Match method was able to show numerically that the correctness of the data varies greatly among the IRRs.