Hardware relevant to networking and Internet usage includes:
- • Network Interface Controller (NIC)
- • Cables, wireless, and network switches
- • Modem
- • Router.
NIC and MAC Addresses
The Network Interface Controller (NIC) in a computer has a unique identifier assigned by the manufacturer, called a Media Access Control (MAC) address. The MAC address helps identify a particular device, especially on a local network. A tech-savvy cybercriminal can change the MAC address of his NIC to disguise his device, conduct attacks, and impersonate other computers.
Cables, Wireless, and Network Switches
One of the main functions of a computer is to send and receive all kinds of data, so it is important to consider how the data travels between computers, routers, and switches. The data has to get from Point A to Point B, and often that transmission is through a cable. Traditional cables are made of copper, transmitting electrical signals that are converted to and from bits as they enter or exit a computer. Newer cables are fiber-optic, transmitting the data as bursts of light through specialized fibers. Whatever the type of cable, the signals sent through them degrade over distance, and periodic boosting through devices such as switches helps to relay, or repeat, the signal.
Data also can be transmitted wirelessly. Wireless transmission uses radio signals that travel through the air as radio waves. All wireless technology relies on some form of hardware to transmit and relay the radio signals. For example, our cell phones connect to cell towers that send and receive wireless data, including phone conversations, Internet surfing, email, and text messages. Our computers and other devices connect to Wi-Fi networks to send and receive wireless signals. Wireless earbuds, mice, and keyboards also send and receive data through the air.
As data travels, it can be intercepted. If the data goes through a cable, securing the cable itself and endpoints from physical access is important to ensure data security. If the data goes through the air, it is potentially accessible to anyone in the vicinity, unless it is secured by encryption.
A switch is a network hardware device that forwards data, but does so automatically, without thinking or processing anything as a router would. Switches are important to relay data over long distances, because otherwise the data signal degrades over the length of the cable and would not reach the destination. Switches also can be a point of compromise for criminals seeking unauthorized access to data.
The modem is a piece of external hardware that sits between the computer and the Internet service provider. Typically, Internet service comes into a home or business through a cable and connects to a modem. The modem acts as a translator. In the early days of the Internet. data was transmitted using telephone lines and analog sounds, and the modem did the translating into computer data protocols. Today, the modem is still needed to translate between different data transmission protocols - those inside your network, and those controlled by the Internet provider.
Routers “route” data and information. Routers are needed in the business and home environment to move data among the many computing devices on a network. In the home, the modem and router might be housed within a single hardware unit.
In the common home set-up, the modem connects to the router, which then connects to computing devices either by cable or wirelessly. The router establishes a network and routes data along it, allowing multiple devices to communicate with one another and share resources, especially Internet access. A typical home Wi-Fi router can allow a dozen devices to connect wirelessly, all accessing the Internet simultaneously through a single modem. The router keeps track of every conversation that every device in the home is having with every website or other Internet location, and ensures each conversation can proceed without any of the data getting mixed up. Consider it like a mailroom that sends and receives mail on behalf of many building occupants. The networks of an organization are more complex, so more sophisticated routers are used to keep that data moving properly.
Routers create routing tables to keep track of the various devices in the network, and to keep track of their communications. This function makes routers a potential source of evidence in an investigation, since the tables may contain valuable information about who was using a particular network and what communication occurred. Routers are also susceptible to compromise by cybercriminals. Routers have firmware (an operating system) and. like every application, vulnerabilities are periodically discovered. If this firmware is not updated regularly, an attacker may be able to compromise the router. Routers have administrator portals that are secured with a password, and weak or default passwords also can make routers vulnerable to attack.
Since Wi-Fi networks move data through the air, the data is subject to interception. Well-secured Wi-Fi networks use strong encryption to transmit data, and require a strong password to join the network. An open, or public, Wi-Fi network allows anyone to join it. Data transmitted on these unsecured networks is available for anyone to see.