单项选择题
A.ip sla monitor low-memory
B.ip sla group schedule
C.ip sla reaction-trigger
D.ip sla enable timestamp
单项选择题 YouarethenetworkadministratorofasmallLayer2networkwith50users.Lately，usershavebeencomplainingthatthenetworkisveryslow.Whiletroubleshooting，younoticethattheCAMtableofyourswitchisfull，althoughitsupportsupto12，000MACaddresses.Howcanyousolvethisissueandpreventitfromhappeninginthefuture？（）
单项选择题 Whentroubleshootingtheissue，younoticetheelectionofanewrootbridgewithanunknownMACaddress.KnowingthatallaccessportshavethePortFastfeatureenabled，whatwouldbetheeasiestwaytoresolvetheissuewithoutlosingredundantlinks？（）
多项选择题 Youarethenetworkadministratorofamedium-sizedcompany，andusersarecomplainingthattheycannotsendemailstosomeorganizations.Duringyourtroubleshooting，younoticethatyourDNSMXrecordisblacklistedbyseveralpublicblacklistfilters.AfterclearingtheselistingsforyourIPaddress，andassumingthatyouremailserverhastherightvirusprotectioninplace，whataretwopossiblesolutionstopreventthisfromhappeninginthefuture？（）