A. It resembles a Layer 2 bridge.
B. Traffic flow through the IPS resembles traffic flow through a Layer 3 router.
C. Inline interfaces which have no IP addresses cannot be detected.
D. Malicious packets that have been detected are allowed to pass through， but all subsequent traffic is blocked.

A. Use CBWFQ to queue the peer-to-peer traffic into the default traffic class.
B. Use class-based WRED to randomly drop the peer-to-peer traffic during network congestions. 
C. Use class-based policing to limit the peer-to-peer traffic rate.
D. Use class-based shaping to delay any excessive peer-to-peer traffic.