Patent ID: 7123615
Filing Date: 2006-10-17
Classification: H04L

Abstract:
1. A stack comprising a plurality of network units and a cascade connection between the network units, each network unit comprising: a) a multiplicity of external ports at which addressed packets can be received and from which packets can be forwarded; b) at least one cascade port for sending packets to and receiving packets from a cascade connection to other network units; c) a router which is responsive to network protocol data in a received packet to determine a subsequent route for said received packet, said router having means defining a network (IP) address for use in routing said packets; and d) at least one bridge responsive to media access control addresses in said packets to convey packets between said router and said external ports; wherein each of the routers operate to route packets received at any one of the multiplicity of external ports of the respective network unit and such packets are thereafter bridged by at least one of the bridges to at least one external port by which such packets leave the stack; wherein the router of one of the said network units operates in a lead mode wherein the lead router sends its network address for use by the routers in each other network unit in the stack; wherein the network units are operative to participate in a predetermined process for determining which single one of the network units shall have its router in the lead mode; wherein each network unit other than the unit having its router in the lead mode has its router in a subordinate mode wherein selected ancillary functions are suppressed; and wherein the suppressed functions include responses to ARP (address resolution protocol) requests to a router interface in the unit.