A switch is an internal device that connects all users in a local-area network. The switch has a table listing the MAC addresses of the host connected to it:

Figure 6: Cisco switch

Once the switch has been installed, it builds up a routing table; each host is identified by their MAC address. The switch delivers the packet only to the host that requires the packet. Switches can be stacked when there are more than 48 users connected to the network:

Figure 7: Network connections

A computer has an ethernet cable that plugs into a wall jack, ...

Get CompTIA Security+ Certification Guide now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.