单项选择题
Two islands of IPv6 networks that are running ISIS （IPv6 IGP） must be connected using a tunnel over anIPv4 network. Which tunneling method can be used to achieve this goal？（）
A.GRE tunnels B.automatic 6 to 4 tunnels C.ISATAP tunnels D.manual tunnels （RFC 2893）
多项选择题 Whichtworequirementstodeploy6PEand6VPEsolutionsaremandatory？（）
多项选择题 WhichtwostatementsaboutDS-Litearetrue？（）
单项选择题 Whichconfigurationpreventstrafficthatissourcedfromtheuniquelocaladdressscopetobesentoutofthelinktotheupstreamserviceprovider？（）
