When troubleshooting duplex mismatches， which two are errors that are typically seen on the half duplexend？（）

单项选择题Whichconfigurationisusedtoenablerootguard？（）

A.interface gig3/1  spanning-tree guard root
B.interface gig3/1  spanning-tree root guard
C.interface gig3/1  spanning-tree root-guard
D.interface gig3/1  spanning-tree root-guard default

单项选择题WhichtypesofprefixeswillarouterrunningBGPmostlikelyadvertisetoanIBGPpeer，assumingitisnotconfiguredasaroutereflector？（）

A. prefixes received from any other BGP peer and prefixes locally originated via network statements or redistributed
B. all prefixes in its routing table
C. prefixes received from EBGP peers and prefixes locally originated via network statements or redistributed
D. prefixes received from EBGP peers and prefixes received from route reflectors
E. prefixes received from other IBGP peers， prefixes received from EBGP peers， and prefixes redistributed to BGP
F. prefixes received from other IBGP peers and prefixes received from route reflectors

多项选择题Whichtwostatementsaretrueabout802.1s？（）

A.802.1s supports a reduced number of spanning-tree instances.
B.802.1s has better convergence times than 802.1w.
C.802.1s does not support load balancing over the same physical topology.
D.The CPU utilization for 802.1s is lower than the CPU utilization for 802.1w.

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WhichNetFlowversionshouldbeusedtocollectaccountingdataforIPv6traffic？（）

A.version 1
B.version 5
C.version 7
D.version 8
E.version 9