TCP Handshake is the process used to establish a TCP connection between two hosts. It is commonly known as the “three-way handshake” and ensures a reliable connection for data transfer.

Three-Way Handshake Steps

1. Client → Server: SYN — The client sends a SYN (synchronize) packet to start the connection.
2. Server → Client: SYN-ACK — The server responds with a SYN-ACK packet, acknowledging the request.
3. Client → Server: ACK — The client sends an ACK to confirm, completing the handshake. Data transfer begins afterward.

Why TCP Handshake is Important

• Ensures proper packet ordering and delivery.
• Provides a reliable stream-based connection over TCP.
• Helps prevent certain types of attacks, such as SYN floods, using techniques like SYN cookies.

TCP Handshake and My IP

• The handshake confirms that packets from your My IP address are recognized by the server.
• Attackers using IP spoofing cannot complete a full handshake, preventing them from establishing a reliable connection.
• This process applies to both IPv4 and IPv6 networks.

FAQ

• What happens if the handshake fails? — The connection is not established; the client may retry or show an error.
• What is a SYN flood? — An attack where many fake SYN packets are sent to overwhelm a server. Mitigation techniques are required.
• Does the handshake work for IPv6? — Yes, TCP operates the same way over IPv6 networks.
• How does it relate to My IP address? — Only packets from the correct IP can complete the handshake, verifying the client’s identity.