A.Designated Root CostB.bridge ID priorityC.max ageD.br……

单项选择题Totroubleshootnetworkissuesmoreaccurately，millisecondsshouldbeincludedinthesyslogoftherouter.Whichcommandwillachievethis？（）

A.service timestamps log datetimec msec
B.logging timestamps msec
C.syslog timestamps hour minute second miliseconds
D.service logging timestamp msec
E.logging service timestamp msec

单项选择题OnarouterthatisconfiguredwithmultipleIPSLAprobes，whichcommandcanbeusedtomanagetheCPUloadthatwascreatedbytheperiodicprobing？（）

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？（）

A.Upgrade the switches
B.Configure BPDU guard
C.Configure VLAN access lists
D.Configure port security
E.Configure Dynamic ARP inspection

单项选择题Whentroubleshootingtheissue，younoticetheelectionofanewrootbridgewithanunknownMACaddress.KnowingthatallaccessportshavethePortFastfeatureenabled，whatwouldbetheeasiestwaytoresolvetheissuewithoutlosingredundantlinks？（）

A.Enable bpduguard globally.
B.Enable rootguard.
C.Enable loopguard.
D.Enable spanning tree.
E.Enable UDLD

多项选择题Youarethenetworkadministratorofamedium-sizedcompany，andusersarecomplainingthattheycannotsendemailstosomeorganizations.Duringyourtroubleshooting，younoticethatyourDNSMXrecordisblacklistedbyseveralpublicblacklistfilters.AfterclearingtheselistingsforyourIPaddress，andassumingthatyouremailserverhastherightvirusprotectioninplace，whataretwopossiblesolutionstopreventthisfromhappeninginthefuture？（）

A.Change your Internet provider.
B.Change your public IP address.
C.Allow the email server to send traffic only to TCP port 25.
D.Put your email server in a DMZ.
E.Use a separate public IP address for your email server only.