多项选择题
Which IOS features are used to avoid Routing loops when dynamic Routing protocols are used betweenPE and CE in MPLS-VPN networks？（）
A.Site Of Origin SOO. B.SHAM links with OSPF C.BGP cost community D.BGP feature allow-as in E.RPF Reverse Path forwarding. F.Access-list Control in Distance Vector protocol like RIP and EIGRP.
单项选择题 BCP（BestCommonPractices）38/RFC2827IngressandEgressPacketFilteringwouldhelpmitigatewhatclassificationofattack？（）
单项选择题 BasedonthefollowingoutputinR1，whichstatementistrue？（）
单项选择题 TheOuter.1QtagrepresentscustomerVLANIDandinner.1QtagrepresentsProviderVLAN？（）
