Abstract: The invention solves the problem of maintaining Route information Field (RIF) information in a router for populating the RIF field of packets routed by the router, by storing the RIF information with the Layer 2 address in the address binding table. The address binding table establishes a binding between a Layer 2 address and a Layer 3 address of a station. The Layer 2 address in the address binding table is extended to include the RIF information. The address binding table is normally maintained in the router in an architecture which permits rapid access for fast switching such as cut through routing. A separate RIF cache table, requiring a separate time consuming table look-up is thereby avoided. The address binding table is referred to as the Address Resolution Protocol (ARP) Table in IP protocol. The Layer 2 address is extended to include both MAC address and REF information.

Abstract: A router transmits an ARP Explorer request packet onto a subnetwork in order to learn the route (RIF information) from the router to an end station. The end station receives a plurality of ARP Explorer request packets from the router because of multiple paths in an SRB network, and the end station transmits an ARP Explorer response packet in response to each ARP Explorer request packet received. The invention adopts the path of the first ARP Explorer response packet received by the router from the end station for the RIF information from the router to the end station, and uses a “duplicate ignore” timer in order to avoid freezing this route into the router tables. The timer begins running upon receipt of the first ARP Explorer response packet, and expires after an “update time interval”. No further ARP Explorer response packet is processed until after expiration of the update time interval.