Subinterfaces are logical divisions of a physical interface that allow a router to communicate with multiple networks using a single LAN port. Subinterfaces can have different IP addresses, VLANs, and routing protocols. They are useful for reducing the number of physical interfaces and cables needed, as well as improving network performance and security.
References:
Subinterfaces - CompTIA Network+ N10-008 Domain 1.21 - YouTube1
CompTIA Network+ Certification Exam Objectives, page 92
Which of the following is a characteristic of the application layer?
It relies upon other layers for packet delivery.
It checks independently for packet loss.
It encrypts data in transit.
It performs address translation.
The application layer is the highest layer of the OSI model, and it provides the interface between the user and the network. It does not handle the details of packet delivery, such as addressing, routing, error checking, or encryption. Those functions are performed by the lower layers of the OSI model. The application layer only focuses on the format, content, and presentation of the data.
References:
Understanding the OSI Model - N10-008 CompTIA Network+ : 1.11
CompTIA Network+ Certification Exam Objectives, page 92