Which the following flags are used to establish a TCP connection? (Select TWO).

A.
PSH

B.
ACK

C.
SYN

D.
URG

E.
FIN

Explanation:
To establish a TCP connection, the three-way (or 3-step) handshake occurs:
SYN: The active open is performed by the client sending a SYN to the server. The client sets the
segment’s sequence number to a random value A.
SYN-ACK: In response, the server replies with a SYN-ACK. The acknowledgment number is set to
one more than the received sequence number i.e. A+1, and the sequence number that the server
chooses for the packet is another random number, B.
ACK: Finally, the client sends an ACK back to the server. The sequence number is set to the
received acknowledgement value i.e. A+1, and the acknowledgement number is set to one more
than the received sequence number i.e. B+1.