Masataka Ohta wrote:
Yes, lacking proper acknowledgements from 131.112.32.132, the peer will terminate the stream.Exactly.That is, you can't send proper acknowledgements, unless you can receive packets to 131.112.32.132, which is the return routability.Not true. If you open a TCP session and receive the first few packets, it is easy enough to generate fake ACKs.Assuming that there is no packet losses and that the attacker send acks slowly enough, maybe.
The attacker doesn't need to send the acks very slowly. See Stefan Savage, Neal Cardwell, David Wetherall, and Tom Anderson, "TCP Congestion Control with a Misbehaving Receiver", CCR, 1999. Note especially that after some initial data stream, the attacker can ignore incoming data (attack 3). --Pekka Nikander