单项选择题 Whichofthefollowingprotocolsenablesagroupofrouterstoformasinglevirtualrouter，andthenusetherealIPaddressofarouterasthegatewayaddress，asdefinedinRFC2338？（）

单项选择题 Inthehardwareaddress0000.0c07.ac0av，whatdoes07.acrepresent？（）

单项选择题 YouwanttoimplementrouterredundancyintheCompanynetworkusingthebestmethodavailable.WhichprotocolspecifiedbyRFC2281providesnetworkredundancyforIPnetworks，ensuringthatusertrafficimmediatelyandtransparentlyrecoversfromfirst-hopfailuresinnetworkedgedevicesoraccesscircuits？（）A.ICMPB.IRDPC.HSRPD.STPE.Noneoftheotheralternativesapply