Which layer is responsible for identifying hosts?

Which layer is responsible for identifying hosts?

• A. Network Layer
• B. Transport Layer
• C. Application Layer
• D. Physical Layer

Answer: (A)

Identifying hosts across a network is handled at the network layer, which is responsible for logical addressing and routing. It assigns IP addresses to hosts and carries packets with source and destination IPs, guiding data from the origin host to the destination across multiple networks. The transport layer sits above it and uses port numbers to deliver data to the correct application on a host, not to identify the host itself. The application layer deals with service-specific communication and may rely on DNS for hostnames, but the actual mechanism that identifies where data should go on a network is the network layer. The physical layer merely transmits raw bits over the medium and does not perform host identification.

Identifying hosts across a network is handled at the network layer, which is responsible for logical addressing and routing. It assigns IP addresses to hosts and carries packets with source and destination IPs, guiding data from the origin host to the destination across multiple networks. The transport layer sits above it and uses port numbers to deliver data to the correct application on a host, not to identify the host itself. The application layer deals with service-specific communication and may rely on DNS for hostnames, but the actual mechanism that identifies where data should go on a network is the network layer. The physical layer merely transmits raw bits over the medium and does not perform host identification.