There are three different ways to use the OSI model: Bottom up – troubleshooting by going from the physical layer (layer 1) up to the application layer (layer 7) Top down – troubleshooting by going from the application layer (layer 7) down to the physical layer (layer 1)

In what layer do you start troubleshooting?

In any network, most of the problems occur at the physical, data-link, and network layers. Therefore, it is always advisable to start troubleshooting from the physical layer and gradually proceed to the application layer.

What is physical layer troubleshooting?

Common symptoms of network problems at the physical layer include: Performance lower than baseline - The most common reasons for slow or poor performance include overloaded or underpowered servers, unsuitable switch or router configurations, traffic congestion on a low-capacity link, and chronic frame loss.