Network Working Group Paul R. Johnson (BBN-TENEX) RFC # 677 Robert H. Thomas (BBN-TENEX) NIC # 31507 January 27, 1975 The Maintenance of Duplicate Databases Preface: This RFC is a working paper on the problem of maintaining duplicated databases in an ARPA-like network. It briefly discusses the general duplicate database problem, and then outlines in some detail a solution for a particular type of duplicate database. The concepts developed here were used in the design of the User Identification Database for the TIP user authentication and accounting system. We believe that these concepts are generally applicable to distributed database problems. Johnson & Thomas