Which of the following protocols operates at Layer 3 of the OSI model?

The protocol that operates at Layer 3 of the OSI model is the Internet Protocol (IP). Layer 3, known as the Network Layer, is responsible for routing packets of data from the source to the destination across different networks. IP facilitates the addressing and routing of these packets, ensuring that data effectively moves through various interconnected networks to reach its endpoint.

This layer handles logical addressing (such as IP addresses), which is essential for identifying hosts on a network and guiding the data packets to their appropriate destinations. The protocols that function at this layer are crucial for implementing network layer services, including the management of traffic between different networks.

In contrast, protocols such as Simple Network Management Protocol (SNMP), Hypertext Transfer Protocol (HTTP), and Simple Mail Transfer Protocol (SMTP) operate at different layers of the OSI model. SNMP is used for network management and operates at Layer 7, the Application Layer. HTTP, which is used for transferring web pages, also operates at Layer 7. SMTP, a protocol for sending emails, is another Application Layer protocol. These distinctions highlight why IP is the correct choice for Layer 3.