What are the mandatory，well-known BGP attributes？（）

单项选择题YouuseOSPFasyournetworkroutingprotocol.YouusethecommandshowiprouteandyouseeseveralroutesdescribedasO，OIA，OE1，andOE2.Whatroutesareinyourarea？（）

A.O IA
B.O E1
C.O E2
D.O

单项选择题YourCisconetworkcurrentlyrunsOSPFandyouhaveaneedtopolicy-routesomespecifictraffic，regardlessofwhattheroutingtableshows.Whichoneoftheseoptionswouldenableyoutopolicy-routethetraffic?（）

A.source IP address and the protocol （such as SSL，HTTPS，SSH）
B.the packet Time to Live and the source IP address
C.type of service header and DSCP value
D.destination IP address

多项选择题InyourCiscoEIGRPnetwork，younoticethattheneighborrelationshipbetweentwoofyourrouterswasrecentlyrestarted.Whichtwoofthesechoicescouldhavemadethisoccur？（）

A.An update packet with init flag set from a known， already established neighbor relationship was received by one of the routers.
B.The ARP cache was cleared.
C.The counters were cleared.
D.The IP EIGRP neighbor relationship was cleared manually.

单项选择题InBGProuting，whatdoestheruleofsynchronizationmean？（）

A.A BGP router can only advertise an EBGP learned route，provided that the route is an IGP route in the routing table.
B.A BGP router can only advertise an IBGP learned route，provided that the route is an IGP route in the routing table.
C.A BGP router can only advertise an IBGP learned route，provided that the route is an IGP route that is not in the routing table.
D.A BGP router can only advertise an EBGP learned route，provided that the route is a metric of 0 in the BGP table.

单项选择题YouhavearouterrunningBGPfortheMPLSnetworkandOSPFforthelocalLANnetworkatthesalesoffice.ArouteisbeinglearnedfromtheMPLSnetworkthatalsoexistsontheOSPFlocalnetwork.ItisimportantthattherouterchoosesthelocalLANroutebeinglearnedfromthedownstreamswitchrunningOSPFratherthantheupstreamBGPneighbor.Also，ifthelocalOSPFroutegoesaway，theBGProuteneedstobeused.WhatshouldbeconfiguredtomakesurethattherouterwillchoosetheLANnetworkasthepreferredpath？（）

A.static route needs to be added
B.floating static route needs to be added
C.bgp backdoor command
D.ospf backdoor command