Dynamic packet filters firewall are fourth generation firewalls that work at

Fourth Generation Firewalls are also known as stateful firewalls. The most important upgrade from First Generation Firewalls is the ability to keep track of the TCP connection state. Greatly prevents hackers access, also these firewalls are able to determine if packets are a part of a new connection or existing connection, relying on a three-way handshake with TCP.

Additional Information

TCP (Transmission Control Protocol):

• TCP (Transmission control protocol) is a connection-oriented reliable transport protocol. It provides a process to process communications using port numbers.

UDP (User datagram protocol):

• UDP (User datagram protocol) is called a connectionless, unreliable transport protocol.
• UDP protocol encapsulates and decapsulates messages in an IP datagram.

Application Layer Protocol:-

• In the Internet protocol stack, when data is sent from device A to device B, the 5th layer to receive data at B is the Application layer.
• It consists of protocols that focus on process-to-process communication across an IP network and provides a firm communication interface and end-user services.
   

Session Layer Protocol:-

• The Session Layer is the 5th layer of the OSI model.
• The session layer controls the dialogues (connections) between computers. It establishes, manages, and terminates the connections between the local and remote applications.