Which networking protocol is primarily responsible for the addressing and routing of packets across networks?

The Internet Protocol (IP) is the primary networking protocol responsible for the addressing and routing of packets across networks. IP operates at the network layer of the OSI model and deals with how data is packaged, addressed, transmitted, routed, and received. Each device on a network has a unique IP address, which allows data packets to be sent to and from specific devices.

IP is essential because it ensures that data can find the correct destination across potentially complex networks, and it manages the paths that packets take to reach their destination. This routing capability is crucial for the functioning of the internet and other networks, enabling devices to communicate with one another reliably.

In contrast, Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) are transport layer protocols that work on top of IP. TCP is connection-oriented and ensures reliable delivery of packets, while UDP is connectionless and allows for faster transmission by sacrificing reliability. File Transfer Protocol (FTP) operates at the application layer and is used specifically for transferring files rather than for addressing and routing packets.