Need to connect to a network and abide by protocols
IP address
Identifies devices on a network, can be assigned by an administrator or DHCP, not fixed and depend on the network
Types of IP addresses
IPv4 (8 numbers separated by dots, e.g. 192.168.1.1)
IPv6 (8 groups of hexadecimals separated by colons, e.g. 2001:0268:0000:0042:0000:8u2e:0370:7334)
IPv6 was developed because the number of devices is growing faster than the number of physical users
MAC address
A universally unique identifier made up of 6 pairs of numbers/letters, specific to the network interface card (NIC)
Uses of MAC addresses
Identifying devices on a network
Tracking devices on a network
Changing device's access to a network
Adjusting dynamic/static IP addresses
Each time a device connects to a network, it is identified by DHCP (usually using its MAC) and given the same IP address as before
Device names are not the best way to identify devices on a network as several devices can have the same name
Components of wired and wireless networks
Cables (Cat5, Cat6, optical fibers)
Wireless access point (WAP)
Gateway
Router
Switch
Booster
Server
Cables
Used to connect devices in a wired network, speed measured in Mbit/s or Gbit/s
Wireless access point (WAP)
Connects devices with WiFi connectivity to a wired network wirelessly, built into routers and boosters
Gateway
Connects LAN to WAN
Router
Stores all the connected device's IP addresses and forwards network traffic using the fastest route
Switch
Has many ports to connect devices with wires
Booster
Amplifies a network signal to cover larger distances
Server
A computer that shares its resources with connected devices, called clients
Types of servers
Authentication server
Print server
File server
Application server
Web server
Authentication server
Checks usernames and passwords when a user logs in, provides an electronic certificate to access resources
Print server
Manages multiple printers, deals with print requests from client computers and adds jobs to a queue
File server
Allows users to access shared and private storage
Application server
Provides clients with access to applications that can be run directly from the server
Web server
Processes requests for data made via HTTP, all the content stored on web servers is the World Wide Web
Aspects needed to connect to and use the internet
Internet service provider
Web browser
Search engine
Filter software
Internet service provider
Grants access to telecommunications infrastructure
Web browser
Takes requests and guarantees access to web servers
Search engine
Allows users to enter keywords which are compared with web pages stored in a database to provide the most relevant results
Filter software
Allows administrators to control users from accessing inappropriate/risky content by filtering web pages through their URL (web address)
Types of LAN/home networks
Peer-to-peer network
Client-server network
Peer-to-peer network
Devices are connected to each other and share resources without a server
Shared file and storage
Shared peripherals
Easier communication
More flexibility
Better media usage
Shared access to the internet
Client-server network
All devices are connected to one server
Roaming profiles - log into your account from any device
Administrator control over user access rights
Centralised administration - entire networks easily moderated and kept safe
Centralised backup - no hassle for individual users, backup is automated
Shared software
Shared storage and file access - file permissions can be set, amount of storage available to others
Techniques for securing data on networks
Logins and passwords
Firewalls
Encryption (Caesar cipher, symmetric key, public key)
Wireless encryption protocols (WEP, WPA)
Virtual private networks (VPNs)
Logins and passwords
Users can only access resources with the correct login details, passwords are used to authenticate a user to a network
Firewalls
Found in gateways, control what enters the network or LAN
Encryption
The process of encoding, scrambling and jumbling data so unauthorised users can't understand it
Caesar cipher
All data is shifted by a certain number of units to the left, the number of units is the key
Symmetric key encryption
Uses the same key to encrypt and decrypt
Public key encryption
Uses two mathematically related keys, one public key to encrypt and one private key to decrypt
Wireless encryption protocols
WEP - all data sent out of a network is encrypted using the same key
WPA - every single device has a unique key on the network, every data packet sent out is encrypted with a unique key
Virtual private network (VPN)
Allows you to access LANs from remote locations, used for secure payments, staying away from tracking, accessing work network from home, accessing geographically locked content