At which OSI layer is a destination IP address added to a PDU during the encapsulation process?
- network layer
- application layer
- transport layer
- presentation layer
Answers Explanation & Hints: The destination IP address is added to a Protocol Data Unit (PDU) at the Network layer during the encapsulation process. The Network layer is the third layer of the OSI (Open Systems Interconnection) model, and it is responsible for routing and forwarding data between different networks. The Network layer adds the source and destination IP addresses to the PDU header, which is used by routers to forward the data to its destination. The Application layer is the top layer of the OSI model and it provides interfaces for application-level protocols. The Transport layer is responsible for end-to-end communication between processes running on different hosts. The Presentation layer is responsible for data formatting and conversion.