In addition to smart phones and mobile devices, there are many other components that can be part of a local area network.Some examples of network components are personal computers, servers, networking devices, and cabling. These components can be grouped into four main categories:
- Network devices
- Network media
The network components that you are probably most familiar with are hosts and shared peripherals. Remember that hosts are any devices that send and receive messages directly across the network.
Shared peripherals are not directly connected to the network, but instead are connected to hosts. The host is then responsible for sharing the peripheral across the network. Hosts have software configured to enable people on the network to use the attached peripheral devices.
The network devices, as well as the networking media, are used to interconnect hosts. Networking devices are sometimes referred to as “intermediate devices” because they are usually located in the path that messages take between a source host and a destination host.
The term network media describes the cables and wires used in wired networks, along with radio frequency waves used in wireless networks. These wired and wireless networks provide the paths over which messages travel between the various network components.
Some devices can play more than one role, depending on how they are connected. For example, a printer directly connected to a host (local printer) is a peripheral. A printer that is directly connected to a network device and participates directly in network communications is a host.
Ethernet is technology commonly used in local area networks. Developed at Xerox PARC, Ethernet was commercially introduced in 1980 by Digital Equipment Corporation (DEC), Intel, and Xerox. Ethernet was later standardized in 1983 as IEEE 802.3. Devices access the Ethernet LAN using an Ethernet Network Interface Card (NIC). Each Ethernet NIC has a unique address permanently embedded on the card known as a Media Access Control (MAC) address.
Connecting End-User Devices
To physically connect to a network, an end-user device must have a network interface card (NIC). The NIC is a piece of hardware that enables the device to connect to the network medium, either wired or wireless. It may be integrated into the device motherboard or may be a separately installed card.
In addition to the physical connection, some configuration of the operating system is required for the device to participate in the network. Most networks connect to the Internet and use the Internet to exchange information. An end-user device requires an Internet Protocol (IP) address, as well as other information, to identify it to the other devices in the network. As shown in the figure, there are three parts to the IP configuration which must be correct for the device to send and receive information on the network:
- IP address – identifies the host on the network.
- Subnet mask – is used to identify the network on which the host is connected.
- Default gateway – identifies the networking device that the host uses to access the Internet or another remote network.
Note: Most network applications use a domain name, such as www.cisco.com, instead of an IP address when accessing information on the Internet. A DNS server is used to translate the domain name to its IP address. Without an IP address of a DNS server, the user will have difficulty accessing the Internet.