多项选择题
A.root guard
B.loop guard
C.BPDU guard
D.UDLD
E.BPDU skew detection
单项选择题 CustomerXhasahub-and-spokeFrameRelaynetwork，withacentralofficeandtwobranchoffices（RemoteAandRemoteB）.EachlocationhasonlyonephysicallinktotheFrameRelaycloudandRemoteBhasarouterthatisnotaCiscorouter.Sincetheinstallation，thereisnoconnectivitybetweenRemoteBandthecentraloffice.Whatisapossiblesolutiontothisissue？（）
单项选择题 ForarouterconnectedtotwoISPsforredundancy，usingIPSLAandstaticrouting，howwouldyouconfigureuRPFontheuplinkinterface？（）
单项选择题 Beforeinsertinganewswitchinthenetwork，thenetworkadministratorchecksthattheVTPdomainnameiscorrect，theVTPmodeissettoserver，andrevisionislowerthantheswitchesinthenetwork.Theadministratorthenconfiguresinterfacesandtrunks，erasesexistingVLANs，andconnectstheswitchtothenetwork.Followingthatprocedure，thereisnoconnectivityinthenetwork.Whatisapossiblecauseofthisproblem？（）