Skip to main content


Home 3-way handshake

3-way handshake

(also TCP 3-way handshake)

3-way handshake definition

A 3-way handshake is a process of three steps in the TCP/IP network to establish a connection between a server and client.

3-way shake example

  • The source sends a SYN message to the receiver. This establishes a connection and helps the two devices synchronize their sequence numbers. The receiver then sends an ACK message – an acknowledgement that the SYN was received. The source sends a SYN-ACK message back to the receiver and confirms the secure connection.