Which three statements about Cisco Flexible NetFlow are true? (Choose three.)
A.
The packet information used to create flows is not configurable by the user.
B.
It supports IPv4 and IPv6 packet fields.
C.
It tracks all fields of an IPv4 header as well as sections of the data payload.
D.
It uses two types of flow cache, normal and permanent.
E.
It can be a useful tool in monitoring the network for attacks.