Final answer:
In TCP/IP communication, each TCP segment contains an initial sequence number (ISN) that helps with sequence number negotiation between the two endpoints. As Bob uses a different ISN for each connection, Eve cannot create a TCP connection with Bob by pretending to be Alice.
Step-by-step explanation:
In TCP/IP communication, when a client wants to establish a TCP connection with a server, it starts by sending a SYN (Synchronize) segment to the server. The server then responds with a SYN-ACK (Synchronize-Acknowledgment) segment. Finally, the client sends an ACK (Acknowledgment) segment to complete the connection establishment process. Each TCP segment contains an initial sequence number (ISN) that helps with sequence number negotiation between the two endpoints.
In the given scenario, Eve, the intruder, is pretending to be Alice and sends a SYN segment to Bob, the server, using Alice's IP address. However, Bob uses a different ISN for each connection. Therefore, when Bob receives the SYN segment from Eve pretending to be Alice, Bob will respond with a SYN-ACK segment containing an ISN that is different from the one expected by Eve. As a result, Eve cannot create a TCP connection with Bob by pretending to be Alice