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

单项选择题 Youadministeranetworkthatusestworouters，R1andR2，configuredasanHSRPgrouptoprovideredundancyforthegateway.RouterR1istheactiverouterandhasbeenconfiguredasfollows：R1#configureterminalR1（config）#interfacefa0/0R1（config-if）#ipaddress10.10.0.5255.255.255.0R1（config-if）#standby1priority150R1（config-if）#standbypreemptdelayminimum50R1（config-if）#standby1trackinterfacefa0/215R1（config-if）#standby1ip10.10.0.20Whichofthefollowingdescribestheeffectthestandbypreemptdelayminimum50commandwillhaveonrouterR1？（）

单项选择题 panyhasimplemented802.1Xauthenticationasasecurityenhancement.Whichstatementistrueabout802.1xport－basedauthentication？（）