CompTIA Network+ Question A-39

When a client calls and describes a problem with a computer not being able to reach the Internet, in which of the following places of the OSI model would a technician begin troubleshooting?

A. Transport layer
B. Physical layer
C. Network layer
D. Session layer

Correct Answer: B

The bottom layer of the OSI reference model is Layer 1, the physical layer.
The physical layer is the layer that defines the hardware elements of a network. These elements include:
Network Interface Cards Network topology Network cabling
The type of signals used for data transmissions
When troubleshooting a network connectivity issue, the first thing you would check is the computer’s network cabling, the network card etc. In other words, the computer’s physical connection to the network.