为自己加油

OSPF选举DR、BDR时会使用如下的那些报文?

A.HELLO报文(HelloPacket);
B.DD报文(DatabaseDescriptionPacket);
C.LSR报文(LinkStateRequestPacket);
D.LSU报文(LinkStateUpdatePacket);
E.LSAck报文(LinkStateAcknowledgmenPacket);