A user has no network connectivity. A check of the associated port indicates that the interface is up， the line protocol is down. Which item would most likely cause this problem？（）

单项选择题Youworkasanetworkengineerforthecompany，youwanttoconfiguretwoBGPspeakerstoformanEBGPsessionacrossafirewall.Ontheengineer’snetwork，thefirewallalwayspermitsTCPsessionsthatareinitiatedfromtheinsidenetwork（thenetworkattachedtotheinsideinterfaceofthefirewall）.WhatprerequisiteisthereforenablingBGPtorunonthisnetwork？（）

A.EBGP multihop will need to be configured for this to work.
B.This should work with normal BGP peering， with no additional configuration on the BGP speakers or the firewall.
C.The BGP protocol port must be opened on the firewall
D.There is no way to make BGP work across a firewall.

单项选择题MultiProtocolLabelSwitching（MPLS）isadata-carryingmechanismthatbelongstothefamilyofpacket-switchednetworks.ForanMPLSlabel，ifthestackbitissetto1，whichoptionistrue？（）

A.The stack bit will only be used when LDP is the label distribution protocol
B.The label is the last entry in the label stack.
C.The stack bit is for Cisco implementations exclusively and will only be used when TDP is the label distribution protocol.
D.The stack bit is reserved for future use.

单项选择题TheOSPFRFC3623GracefulRestartfeatureallowsyoutoconfigureIETFNSFinultivendornetworks.WhenusingOSPFGracefulRestart，whichmechanismisusedtocontinueforwardingpacketsduringaswitchover？（）

A.Reverse Path Forwarding
B.Hardware-based forwarding
C.UDP forwarding
D.Layer 2 Forwarding

单项选择题Youareconfiguringan802.1QtrunkbetweenaLayer2switchandafirewall.Youreadinthedocumentationthatthebestwaytosetupatrunkistosettheportasdynamicdesirable.Thetrunkisnotcomingup.Whichoneoftheseoptionswouldbeavalidexplanation？（）

A.The firewall does not support Cisco Discovery Protocol. You should set the switchport trunk mode ON
B.The firewall does not support Cisco Discovery Protocol. You should set the switchport trunk mode to OFF
C.The firewall does not support Cisco Discovery Protocol. You should set the switchport trunk mode asauto.
D.The firewall does not support DTP. You should set the switchport trunk mode to ON

多项选择题WhichtwoofthefollowingareconsideredvalidrouterIDsforEIGRPv6？（）

A.0.0.0.1
B.0.255.0.1
C.2001：DB8：：1
D.2001：DB8：ABCD：FEEF：：1