Network Hardware

Network interface card (NIC)

A network interface card (NIC) is needed to allow a device to connect to a network (such as the internet).
It is usually part of the device hardware and contains the Media Access Control (MAC) address generated at the manufacturing stage.
Wireless network interface cards/controllers (WNICs) are the same as NICs in that they are used to connect devices to the internet or other networks.
However, they use wireless connectivity utilising an antenna to communicate with networks via microwaves.
They would normally plug into the USB port or be part of an internal integrated circuit.

A MAC address is made up of 48 bits which are shown as six groups of hexadecimal digits with the general format:

It should finally be pointed out that there are two types of MAC address:
- the Universally Administered MAC Address (UAA)
- the Locally Administered MAC Address (LAA).
The UAA is by far the most common type of MAC address and this is the one set by the manufacturer at the factory.
It is rare for a user to want to change this MAC address.

When a device connects to a private network, a router assigns a private IP address to it.
That IP address is unique on that network, but might be the same as an IP address on a separate network.

TIP

MAC addresses	IP addresses
identifies the physical address of a device onthe network	identifies the global address on the internet
unique for device on the network	may not necessarily be unique
assigned by the manufacturer of the deviceand is part of the NIC	dynamic IP addresses are assigned by ISP using DHCP each time the device connects to the internet lsee later
they can be universal or local	dynamic IP addresses change every timea device connects to the internet; static IPaddresses don't change
when a packet of data is sent and received the MAC address is used to identify the sender's and recipients devices	used in routing operations as they specifically identify where the device is connected to the internet
use 48 bits	use either 32 bits (IPv4) or 128 bits IPv6
can be UAA or LAA	can be static or dynamic

IP addresses can be either static (don’t change) or dynamic (change every time a device connects to the internet).
Static IP addresses are permanently assigned to a device by the internet service provider (ISP); they don’t change each time a device logs onto the internet.
Dynamic IP addresses are assigned by the ISP each time a device logs onto the internet. This is done using Dynamic Host Configuration Protocol (DHCP).

Dynamic IP addresses	Static IP addresses
greater privacy since they change each timea user logs on	since static IP addresses don't change, theyallow each device to be fully traceable
dynamic IP addresses can be an issuewhen using, for example, VoIP since thistype of addressing is less reliable as itcan disconnect and change the IP address causing the VoIP connection to fail	allow for faster upload and download speeds
	more expensive to maintain since the device must be constantly running so that information is always available

Routers enable data packets to be routed between different networks, for example, to join a LAN to a WAN.
The router takes data transmitted in one format from a network (which is using a particular protocol) and converts the data to a protocol and format understood by another network, thereby allowing them to communicate.