On the basis of the definitions of different services in various RFCs，traffic with Expedited Forwarding per-hop behavior should be marked as which of these？（）

单项选择题WhichistheresultofenablingIPSourceGuardonanuntrustedswitchportthatdoesnothaveDHCPsnoopingenabled？（）

A.DHCP requests will be switched in the software， which may result in lengthy response times.
B.The switch will run out of ACL hardware resources.
C.All DHCP requests will pass through the switch untested.
D.The DHCP server reply will be dropped and the client will not be able to obtain an IP address.

多项选择题WhichthreestatementsaretrueaboutSourceSpecificMulticast？（）

A.Is best suited for applications that are in the one-to-many category.
B.SSM uses shortest path trees only.
C.The use of SSM is recommended when there are many sources and it is desirable to keep the amount of mroute state in the routers in the network to a.
D.There are no RPs to worry about.

单项选择题Auserhasnonetworkconnectivity.Acheckoftheassociatedportindicatesthattheinterfaceisup，thelineprotocolisdown.Whichitemwouldmostlikelycausethisproblem？（）

A.Speed mismatch
B.Incorrect encapsulation
C.MTU set too low
D.Duplex mismatch

多项选择题ForthefollowingLMItypes，whichthreecanbeconfiguredforusewithFrameRelayonaCiscorouter？（）

A.Cisco
B.ANSI - Annex D
C.Q.931 - Annex B
D.Q.933 - Annex A

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.