Typically，anIPaddressreferstoanindividualhostonaparticularnetwork.IPalsoaccommodatesaddressesthatrefertoagroupofhostsononeormorenetworks.Sunchaddressesarereferredtoasmulticastaddresses，andtheactofsendingapacketfromasourcetothemembersofa(作答本题)groupisreferredtoasmulticasting.Multicastingdone(72)thescopeofasingleLANsegmentisstraightforward.IEEE802andotherLANprotocolsincludeprovisionforMAC-levelmulticastaddresses.ApacketwithamulticastaddressistransmittedonaLANsegment.Thosestationsthataremembersofthe(73)multicastgrouprecognizethemulticastaddressand(74)thepacket.Inthiscase,onlyasinglecopyofthepacketisevertransmitted.Thistechniqueworksbecauseofthe(75)natureofaLAN:AtransmissionfromanyonestationisreceivedbyallotherstationsontheLAN.
A.numerous B.only C.single D.multicast正确答案D
