多项选择题
Which two commands are required to enable multicast on a router， knowing that the receivers only support IGMPv2？（）
A.ip pim rp-address B.ip pim ssm C.ip pim sparse-mode D.ip pim passive
多项选择题 WhichtwooftheseareusedintheselectionofarootbridgeinanetworkutilizingSpanningTreeProtocolIEEE802.1D？（）
单项选择题 SpanningTreeProtocolIEEE802.1sdefinestheabilitytodeploywhichofthese？（）
