Which feature would prevent guest users from gaining network access by unplugging an IP phone and connecting a laptop computer？（）

多项选择题Yournetworkissufferingfromregularoutages.Aftertroubleshooting，youlearnthatthetransmitleadofafiberuplinkwasdamaged.Whichtwofeaturescanpreventthesameissuesinthefuture？（）

A.root guard
B.loop guard
C.BPDU guard
D.UDLD
E.BPDU skew detection

单项选择题Whileyouaretroubleshootingnetworkperformanceissues，younoticethataswitchisperiodicallyfloodingallunicasttraffic.FurtherinvestigationrevealsthatperiodicallytheswitchisalsohavingspikesinCPUutilization，causingtheMACaddresstabletobeflushedandrelearned.Whatisthemostlikelycauseofthisissue？（）

A.a routing protocol that is flooding updates
B.a flapping port that is generating BPDUs with the TCN bit set
C.STP is not running on the switch
D.a user that is downloading the output of the show-tech command
E.a corrupted switch CAM table

单项选择题ForarouterconnectedtotwoISPsforredundancy，usingIPSLAandstaticrouting，howwouldyouconfigureuRPFontheuplinkinterface？（）

A.ip verify unicast source reachable-via any
B.ip verify unicast reverse-path
C.ip verify unicast reverse-path loose
D.ip verify unicast reverse-path strict

多项选择题Voicequalityisbadduetohighdelayandjitteronalink.Whichtwoactionswillimprovethequalityofvoicecalls？（）

A.Increase the queue size of the voice class.
B.Guarantee bandwidth during congestion to the voice class with a bandwidth command.
C.Increase the tx-ring of the egress interface.
D.Implement LLQ for the voice class.
E.Decrease the rx-ring of the egress interface.
F.Decrease the queue size of the voice class.

单项选择题WhatactionwillaBGProutereflectortakewhenitreceivesaprefixmarkedwiththecommunityattributeNOADVERTISEfromaclientpeer？（）

A.It will advertise the prefix to all other client peers and non-client peers.
B.It will not advertise the prefix to EBGP peers.
C.It will only advertise the prefix to all other IBGP peers.
D.It will not advertise the prefix to any peers.