mac address -Layer 2

⇒ physical address and this means [Media Access Control]

⇒ mac address have 6 pairs like this 00:1b:63:84:45:e6 first 3 pairs are identifiers

TCP, UDP, Three-way handshake - Layer 4

⇒ Transmission control protocol [TCP] - User datagram Protocol [UDP]

⇒ TCP working on something called Three-way handshake.

What is Three-way handshake ?

The three-way handshake is a method used in computer networking to establish a connection between two devices over the Internet, such as a client computer and a server. It is also referred to as the TCP three-way handshake or SYN-SYN-ACK handshake.

The three-way handshake consists of three steps:

1. SYN: The client sends a SYN (synchronize) packet to the server to initiate the connection request. This packet contains a sequence number that is used to identify the connection.
2. SYN-ACK: The server responds to the client with a SYN-ACK (synchronize-acknowledge) packet. This packet contains an acknowledgement number that is used to confirm the sequence number received from the client.
3. ACK: The client sends an ACK (acknowledge) packet to the server, which confirms that the client has received the SYN-ACK packet. This completes the three-way handshake, and the connection is established.

Once the connection is established, data can be transmitted between the client and server using the Transmission Control Protocol (TCP). The three-way handshake is an important part of network security, as it helps prevent unauthorized access to a system by ensuring that the connection is initiated by a legitimate client device.

Common Ports And Protocols:

OSI MODEL :