What are BCP 38 (Best Common Practices 38) / RFC 2827 Ingress Packet Filtering Principles?
(Choose three.)

A.
Filter Smurf ICMP packets.

B.
Filter as close to the core as possible

C.
Filter as close to the edge as possible

D.
Filter as precisely as possible

E.
Filter both source and destination where possible.

Explanation:
1.13. Security in core