This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: TCP Questions (10 points each) 1. Suppose a host wants to establish the reliability of a link by sending packets and measuring the percentage that are received; routers, for example, do this. Explain the difFculty doing this over a TCP connection. 2. Suppose an idle TCP connection exists between sockets A and B. A third party has eavesdropped and knows the current sequence number at both ends. (a) Suppose the third party sends A a forged packet ostensibly from B and with 100 bytes of new data. What happens? Hint: Look up in Request for Comments 793 what TCP does when it receives an ACK that is not an "acceptable ACK." (b) Suppose the third party sends each end such a forged 100-byte data packet ostensibly from the other end. What happens now? What would happen if A later sent 200 bytes of data to B? 3. When TCP sends a (SYN, SequenceNum = x) or (¡IN, SequenceNum = x), the consequent ACK has Acknowledgment = x +1; that is, SYNs and ¡INs each take up one unit in sequence number space. one unit in sequence number space....
View Full Document
This document was uploaded on 03/03/2011.
- Fall '09