Essential Network Hardware Components Explained

Network Interface Card (NIC)

The Network Interface Card (NIC), also known as a Media Access Unit (MAU), is the device that connects a station (computer or other network device) to the physical network environment. While often presented as an expansion card for computers, many modern computers have integrated network interfaces, primarily Ethernet.

Sometimes, a network card requires a transceiver. This device connects the physical medium to the card, either because a direct connection is impossible (e.g., 10Base5) or because the medium type differs from what the card supports.

Bridge or Bridges

A bridge interconnects two segments of a computer network or divides one network into two segments. It filters data based on the MAC address. Therefore, a bridge must maintain MAC address tables for the devices connected to each of its ports.

Hub or Concentrator

This equipment centralizes network wiring, but due to its operational method, it is virtually obsolete today. The HUB repeats or replicates all incoming data from one port to all other ports, causing the bandwidth to be divided among all connected computers. The HUB sends a signal shock if it detects a collision. There are three types of hubs: passive, active, and intelligent (smart hub).

Router or Enrutador

This communications equipment allows the connection of a LAN to a WAN. Using routing protocols, the router decides the best route at any given time to send information.

Switch or Switch

A switch is a device that interconnects two or more network segments. It functions like a bridge by selecting which data to pass from one segment to another. By acting as a network filter, it improves LAN performance and has largely replaced the hub today. The switch stores the MAC addresses associated with each connected segment, allowing it to direct data only to the intended segment.

Gateway

Gateways are used to interconnect networks that use completely different protocols and architectures at all communication levels. The translation of information units significantly reduces the transmission rate through these devices.

MAC (Media Access Control)

The MAC address is a unique identifier for each network device. It is composed of 6 bytes: the first three bytes identify the manufacturer, and the last three bytes identify the particular device.