Abstract: A testing apparatus for token ring local area networks (LANs) which can insert into the token ring network without requiring a separate port on a media access unit (MAU). The testing apparatus of the present invention is connected between a regular network station and the MAU. The testing apparatus is insertable into the network through the MAU, and the regular network station is able to insert into the network through the testing apparatus. Once inserted, the regular network station and the testing apparatus act as separate stations in series on the LAN. Due to its central position in this configuration, the testing apparatus is able to test for possible faults that might be present in the network and/or in the station to which it is connected. In addition, since the testing apparatus does not require a separate port on the MAU, no active user on the network needs to be disconnected for any extended period of time.

Abstract: A token ring local area network (LAN) testing apparatus is provided. The apparatus includes hardware and software for keeping track of information related to the origination of a beacon frame that occurs due to a fault in the token ring. When a fault occurs in the token ring, a beacon frame is generated and this frame is useful in reporting the network domain or location that initiated the beaconing condition. This information is useful to the network manager in isolating the token ring fault. In addition to the first or original beacon frame, further or phantom beacon frames can be generated. These phantom beacon frames include those generated by other stations on the token ring experiencing a signal loss due to steps taken by the originating station as a result of the fault. These phantom domains are usually not beneficial to the network manager in isolating the fault on the token ring.

Abstract: System and method for distinguishing duplicate source address replies caused by interconnecting devices connected to a local area network and duplicate source address replies caused by non-interconnecting devices connected to the local area network.The present invention may be implemented through an analyzer. The method includes the following steps: In step 1, the present invention sends a first Address Resolution Request packet for a first Internet Protocol target address. In step 2, all Internet Protocol source address responses replying to the first Address Resolution Request packet are catalogued in a first reply set. In step 3, a second Address Resolution Request packet for a second Internet protocol target address is sent on to the network. In step 4, all Internet Protocol source address responses replying to said second Address Resolution Request packet are catalogued in a second reply set. In step 5, the first reply set is intersected with the second reply set resulting in an intersection set.