The Border Gateway Protocol （BGP）is an interautonomous system（  ）protocol.The primary function of a BGP speaking system is to exchange network （  ）information with other BGP system.This network reachability information includes information on the list of Autonomous System（ASs）that reachability  information  traverses.BGP-4 provides a new set of mechanisms for supporting （  ）interdomain routing.These mechanisms include support for advertising an IP （  ）and eliminate the concept of network class within BGP.BGP-4 also introduces mechanisms that allow aggregation of routes， including （  ）of AS paths.These changes provide support for the proposed supernettting scheme.