Answer:
SYN and ACK.
Step-by-step explanation:
In Computer Networking, a control bit flag is used in transmission control protocol (TCP) to denote a specific state of connection and typically indicates a bit of information (1 bit).
The control bit flags used during the three-way handshake are SYN and ACK. A three-way handshake is used in transmission control protocol (TCP) to establish a reliable connection.
The three-way handshake refers to a client-server communication model which happens in three steps or stages;
1. SYN: this is where the client establishes a connection with the server.
2. SYN-ACK: the server then immediately responds to the server by acknowledging the request.
3. ACK: here the client acknowledges the response of the server and thus create a reliable connection.