In the TCP/IP stack, which layer handles packet routing?

The network layer is responsible for packet routing within the TCP/IP stack. This layer’s primary function is to determine the best path for data packets to travel from the source to the destination across different networks. It accomplishes this by using logical addressing, specifically Internet Protocol (IP) addresses, which allows devices on a network to identify and locate each other.

Routing decisions are made at this layer, which analyzes the network topology and takes into consideration factors like congestion and the current state of network devices to optimize the flow of data. It interacts closely with the underlying data link layer to manage data frames being sent over various network technologies.

In contrast, the transport layer focuses on end-to-end communication, ensuring that data is sent accurately and in sequence. The application layer serves as the interface between users and the network, providing protocols for specific applications such as email or web browsing. The physical layer pertains to the physical connection and data transmission over a medium, dealing with the hardware aspects of the network.