Q2 TCP/IP Model

Question 1

Which layers are involved with the Client machine and Server machine?

Answer 1

These are end hosts running applications. They process data from the application layer down to the physical layer for sending, and from the physical layer up to the application layer for receiving. All five layers are involved.

Question 2

Which layers are involved with the Router?

Answer 2

A router’s primary function is to route and forward network packets.
This involves processing information up to the Network layer to make routing decisions.
Routers also interact with the Data Link layer to handle frames on specific network interfaces and the Physical layer to transmit/receive signals.

Question 3

Which layers are involed with the Switch?

Answer 3

A switch typically operates at the Data Link layer, specifically using MAC addresses to forward frames within a local network. It also operates at the Physical layer to handle the electrical signals on the network cables.

Question 4

Which layers are involved with the Application Gateway?

Answer 4

This type of gateway operates at the Application layer, understanding and potentially modifying the content of specific application protocols (like email or web traffic). It also inherently interacts with all layers below (Transport, Network, Data Link, Physical) to send and receive data.

Question 5

Which layers are involved with the Firewall?

Answer 5

A firewall’s layer involvement depends on its type:
◦ Packet filter firewalls operate up to the Network layer and Transport layer, inspecting IP addresses and port numbers.
◦ Stateful firewalls also operate up to the Transport layer, tracking connection states.
◦ Proxy firewalls (Application Gateways) operate up to the Application layer, inspecting application content.
◦ All firewalls interact with the Data Link and Physical layers to receive and send traffic.