单项选择题
A.Only UplinkFast and BackboneFast are specified in 802.1w； PortFast must be manually configured.
B.Only PortFast is specified in 802.1w； UplinkFast and BackboneFast must be manually configured.
C.None of the proprietary Cisco enhancements are specified in 802.1w.
D.PortFast， UplinkFast， and BackboneFast are specified in 802.1w.
单项选择题 Auserhasnonetworkconnectivity.Acheckoftheassociatedportindicatesthattheinterfaceisup，thelineprotocolisdown.Whichitemwouldmostlikelycausethisproblem？（）
单项选择题 Youworkasanetworkengineerforthecompany，youwanttoconfiguretwoBGPspeakerstoformanEBGPsessionacrossafirewall.Ontheengineer’snetwork，thefirewallalwayspermitsTCPsessionsthatareinitiatedfromtheinsidenetwork（thenetworkattachedtotheinsideinterfaceofthefirewall）.WhatprerequisiteisthereforenablingBGPtorunonthisnetwork？（）
单项选择题 MultiProtocolLabelSwitching（MPLS）isadata-carryingmechanismthatbelongstothefamilyofpacket-switchednetworks.ForanMPLSlabel，ifthestackbitissetto1，whichoptionistrue？（）