In one of packet tracer activity in the book "network fundamentals", it said that devices that are not configured to receive multicast traffic will drop packet at Layer 3. However, in the book "routing protocols and concepts", it said differently. It said " In addition, multicasting updates require less processing by devices that are not RIP enabled. Under RIPv2, any device that is not configured for RIP will discard the frame at the data link layer " (it means Layer 2).
Can anyone help me to explain this? Thank you very much.