Identifying the OSI Layers at Which Various Network Components Operate

When you have an understanding of the OSI model, it is possible to relate network connectivity devices discussed in Chapter 3, "Networking Devices," to the appropriate layer of the OSI model. Knowing at which OSI level a device operates allows you to better understand how it functions on the network. Table 4.2 identifies various network devices and maps them to the OSI model.

Table 4.2. Mapping Network Devices to the OSI Model

Device	OSI Layer
Hub	Physical (Layer 1)
Switch	Data-link (Layer 2)
Bridge	Data-link (Layer 2)
Router	Network (Layer 3)
NIC	Data-link (Layer 2)
WAP	Data-link (Layer 2)

For the Network+ exam, you are expected to be able to identify at which layer of the OSI model certain network devices operate.