Scenario: TCP 3-Way Handshake Interruption
This scenario explores what happens when intermediate routers drop packets during connection establishment.
Q: The client sends a SYN packet, but the server's SYN-ACK is dropped by a router. What happens next?
The client is in the
SYN_SENT state and will eventually trigger a retransmission timeout (RTO). It will retransmit the original SYN packet. The server, meanwhile, is in the SYN_RCVD state and is waiting for the final ACK.Q: Does the server also retransmit anything?
Yes. Since the server never received the client’s final ACK, its own RTO timer will expire, and it will retransmit the SYN-ACK packet. Both sides will attempt to recover the connection independently.