Chapter 16

Page 1

Hardware

NIC (Network interface controller)

Generates and receives electrical signals

Works at the physical and data link layers

Router

Connects networks

Forwards data packets

Works as the network layer

MAC addresses

48-bit identifiers allocated to network devices by the manufacturer

Normally in groups of 6 bytes

The first 3 groups identify the manufacturer

Wireless access points

Enables the temporary connection of devices, usually portable computers, to a network

Normally allows connections from distances up to 100 metres

Methods taken to prevent unauthorised access:

Hiding the SSID

SSID (Service set identifier)

Is a broadcast signal that identifiers a wireless access point

Useful when used a network is likely to be used by outsiders

Encryption

Various ways to encrypt signals

WEP (wired equivalent privacy)

Limiting access

Access points can be configured to accept communications from a limited list of MAC addresses

Page 2

Networks

Collections of connected computing devices

Consist of a number of devices known as nodes