多项选择题
Which three BGP attributes are always communicated in a BGP update packet? （）(Choose three.)
A.MED B.Origin C.AS Path D.Next Hop E.Aggregator
单项选择题 Which packet is sent in response to a BGP Open packet?（）
单项选择题 Once the TCP connection is established, which message type initiates the BGP peering process?（）
单项选择题 Which message is used to transport routing information between BGP peers?（）
