Abstract

A duplicate address condition in a computer network may be detected by a station of the type for attachment to a computer communications network, the network capable of maintaining communications among a plurality of stations, the station having means for receiving a frame, the frame having a source address field and a frame control field; means for maintaining an individual address of the station; means for maintaining a source address list of address, the source address list not containing the individual address; means for determining that a contents of the source address field in the frame matches at least one address in the source address list; means for determining that the frame control field of the frame has a predetermined contents; and, means, responsive to the source address of the frame matching at least one address in the source address list and the frame control field of the frame having the predetermined value, for setting an indicator that a duplicate address condition exists. The predetermined contents of the frame control field further comprises an indication that the frame is a predetermined type of control frame. The predetermined type of claim may be a beacon frame, a claim frame, or some other MAC protocol frame. The list of alias addresses may be stored in a content addressable memory. A cyclical redundancy check may be used for determining that bits from the source address field and bits from the frame control field are error free.

Other References

• European Search Report dated Oct. 30, 1991, for European Application No. 91 30 6585.0
• Ocheltree, Kenneth B., Jan. 23 1989, "FDDI Duplicate Address Problems", International Business Machines, IBM, Research Report
• Ocheltree, Kenneth B., and Montalvo, Rafael M., Oct. 1989, IEEE 14th Conference on Local Computer Networks, in Minneapolis, Minn., "FDDI Ring Management"
• Yang, H. and Ramakrishnan, K. K., "Frame Content Independent Stripping for Token Ring", Proceedings of the ACM, SIGCOM 1990, Sep. 1990
• FDDI SMT-"Fiber Distributed Data Interface (FDDI)-Station Management", Sep. 5, 1989, Draft Proposed American National Standard, X3T9/89-, X3T9.5/84-49, Rev. 5.1, published by American National Standards Institute
• FDDI SMT-"Fiber Distributed Data Interface (FDDI)-Station Management", May 18, 1990, Preliminary Draft Proposed American National Standard, X3T9/90-078, X3T9.5/84-49, Rev. 6.2
• FDDI MAC-"fiber distributed data interface (FDDI)-token ring media access control (MAC)", American National Standard 1987, published by American National Standards Institute, X3.139-1987
• Advanced Micro Devices, Feb. 1989, Specification sheet for chip Am79C83, Title: "Fiber Optic Ring Media Access Controller (FORMAC)" Publication No. 09731
• FDDI PHY-"fiber distributed data interface (FDDI)-token ring physical layer protocol (PHY)", American National Standard, 1988, Published by American National Standards Institute, ANSI X3.148-1988
• J. Winkler, et al.: "Standards and Architecture for Token-Ring Local Area Networks", 1986 Fall Joint Computer Conference, Nov. 1986, Dallas, U.S., pp. 479-488
• Data Communications. vol. 18, No. 15, Nov. 1989, New York, USA, pp. 26-34, "Token ring compatibility: It's time to plug and play" Authors: Jim Carlo and John Hughes
• Computer Networks and ISDN Systems. vol. 11, No. 2, Feb. 1986, Amsterdam, Netherlands, pp. 121-131. "Reliability Mechanisms of the FDDI High Bandwidth Token Ring Protocol" Author: M. J. Johnson
• European Search Report dated Oct. 30, 1991, for European Application No. 91 30 6902.