Refer to the exhibit. Routers A and B are directly connected and running OSPF， but they are unable to form a neighbor relationship. What is the most likely cause？（）

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.

多项选择题Router1isconfiguredforBGPasdual-homedontheCisconetwork.WhichthreeBGPattributesarecarriedineveryBGPupdateonthisrouter（bothIBGPandEBGP）？（）

A.origin
B.router-ID
C.AS-path
D.local-preference
E.next-hop

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

单项选择题Refer to the exhibit. R2 and R3 are routers connected using Ethernet services from a service provider and can receive pings from each other. OSPF is configured as the routing protocol but adjacency is not happening. According to the output of the show commands in the exhibit， what could be the most likely cause of the problem？（）

A.Ethernet interfaces were configured as point-to-point.
B.Process IDs are not matching.
C.Configured bandwidths do not match on both interfaces.
D.Broadcasts and multicast are not being propagated over the Ethernet services.
E.OSPF cost does not match on both interfaces.