A.IBGP updates exchange between trigger router and black hole router
B.EBGP updates exchange between trigger router and black hole router
C.OSPF updates exchange between trigger router and black hole router
D.ISIS updates exchange between trigger router and black hole router

A.The MD5 algorithm inputs the routing updates of arbitrary length and outputs a 128-bit hash
B.The MD5 algorithm inputs the routing updates of every 64bit length and outputs an 8-bit hash
C.Multiple keys are supported
D.Routing updates packets are delivered in encrypted messages
E.Shared secret keys are delivered in encrypted messages