Topic3 Flashcards
What does LAN stand for
Local Area Network
Describe a LAN
Covers small area
Can be Ethernet or wireless or both
Often in schools business university
What is the purpose of a LAN
Sharing files
Connect to printers
Have user accounts stored centrally
What is A WAN
A collection of LANs that are all connected across large geographic sites
Factors that affect performance of networks
Bandwidth
Wired if wireless
Obstructions of wireless networks
What is A NIC
Network interface card
What is bandwidth
The amount of data that can be transferred at a give time
What does the NIC do?
It is an internal piece of hardware that allows devices to to connect to the Network
What is a switch
A device that connects data on a LAN it receives data and transmits it the correct device using the MAC address
What is a router
A piece of hardware in a lan responsible for transmitting data to other networks they direct data were to go
They connect LANS to the internet
What is the benefits of wired connections
Faster
Reliable
Types of wire on a wired connection
Cat 5e
Cat 6
Coaxial
Fibre optic
What are cat5e and cat6 wires
A twisted pair of wires contain 4 pairs of copper wires which are twisted together to stop interference
What are coaxial wires ?
A single cooper wire surround by plastic and for insulation and and a metallic mesh to prevent interference.
What are fibre optic cables?
Transmit data as light they are very fast but expensive
How does wireless connections transmit data
Using wires
Benefits of wireless
More portable
More convenient
Cheaper
What is Bluetooth
A connection between two devices
Low range
Low bandwidth
What is WiFi’
A wireless connection to a LAN
High range
High bandwidth
What is a client server network made up from?
Server and clients
What is a client server network
A Network with a central server that all devices connect to
Files and software are usually stored centrally
Clients send requests to the server for data
Pros for client server
Easier to keep track of files
Easier to perform back ups
Easier to update
Easier to manage network security
Reliable and always on
Cons of client server network
Expensive
Server dependence
May become overloaded
What is peer to peer network
A network without a server where all devices are connected directly
Pros of peer to peer
Easy to maintain
No server dependence
Cons of peer to peer
No centralised management devices need to update and mange own security
Easy to loose track of files
Less reliable
What is star topology
A network where all devices are connected to the centre
Pros of star topology
If a cable or devices fails expect central server the network doesn’t fail
Simple to add more devices
Better performance
Cons of start topology
Every device needs a cable in wired networks
If there is a problem with the switch or server, and the whole network is affected
What is the bus topology?
All devices are arranged in a line and connected to a single backbone cable
What is ring topology?
Ring topology data moves in One Direction around the room, prevent collisions, but only one device can send data at a time
What is mesh topology?
When all devices are connected to each other, the network is decentralised
Benefits of a mess topology
And no single point the network can fail as there is usually a different route
Cons of mesh topology
It’s very expensive, you need a lot of wires and many devices
Difference between full mesh, topology and’s partial topology
Full as where every device is connected
Partial is where most devices are connected, but some I just connected with one route
What are network protocols?
The rules for transmitting data
What are communication protocols?
They specify how communication between two devices must start and end and hold data must be organised
What is a Mac address?
Are unique identifier to each device on the network
How long a Mac addresses?
48 or 64 bit binary numbers, but I converted to hexadecimal to make it simple
What is an IP address?
IP addresses are used when sending data between networks e.g. of the Internet IP addresses are sign is a manually automatically before the devices can access the network
What are the two versions of IP addresses?
IPV4
IPV6
What is IPV4
The ip address with over 4 billion different and are 8 bits long
What is ipv6
A 16 bit long Ip address represent in hexadecimal
What is TCP
Transmission Control Protocol
Sets the rules for how devices connect to networks in charge of splitting data into packets
And checking data is correctly sent
What is IP
Internet protocols
Responsible for directing packets across networks
What is HTTP
Hyper text transfer protocols
Used by web browsers to communicate with web servers
What is HTTPS
A secure version of HTTP encrypts data
What is FTP
File Transfer protocols
Used to access edit and move files between devices on a network
What is POP3
Post office protocols version 3
Used or retrieve emails from a server the server holds the email until it is downloaded
What is IMAP
Internet message access protocols
Used to access emails on a server until deleted by you
You only download a copy
What is smtp
Simple mail transfer protocol
Used to send email
What are layer in networks
A group of protocol with similar functions
They are self contained and don’t know what is happening in other layers
Each layer servers the layer above
Advantages of using layers
Breaks down protocols into manageable pieces
They can be changed within effecting other layers
What is the internet
A network of networks
What is a domain name service
A service used to translate website domain name into ip address making it easier to remember
What is a domain name server
A server which stores ip addresses and matching Ip address
What is hosting
When a business uses its server to store files of other companies
Pros of the cloud
Can access files from almost every where
Easy to increase amount of storage
No need for expensive hardware
No need for It staff
Cons for the cloud
Needs a connection to internet
Dependent on host
Subscription
What is a passive attack?
Where is someone monitors data travelling on the network and intercept any sensitive information they find
What is an active attack?
When someone attacked a network with malware, or other planned attacked
What is an insider attack
Someone within an organisation exports the network access to steal information
What is a brute force attack?
It’s a type of attack, used to gain information by cracking passwords through trial and error
What is a denial of service attack?
Where a hacker tries to stop users from accessing a part of a network website. Most involved flooding the network with uses traffic making it look extremely slow or completely inaccessible.
What is a virus?
Virus attach a copy themselves to certain files. And run auto scrips and spread.
What is a worm?
Worms are like viruses, but they self replicate without any use to help meaning they can spread very quickly
What is a Trojan?
Malware disguised as legitimate software
What are network security threats?
Social engineering
Phishing
SQL injection
What is social engineering?
Is the weight of gaining sensitive information or illegal access networks by influencing people
What are phishing emails
Emails from a person claiming to be from a well known company emails contain links to fake websites so hackers can steal data
What is SQL injection
Structured query language
SQL code is typed into input box which then reveals sensitive information
How to prevent hacks and attacks
Test regularly
Passwords
Install antimalware
What is penetration testing?
When organisations employ specialists to simulate potential attacks
What is physical security?
Physical aspects of the security system, e.g. locks passwords, and security guards
What are user access levels?
Prevent insider attacks control, which parts of the network, different people or groups can access
What is anti malware software?
It is designed to stop and find malware prevent damage to organisations networks
What is a firewall?
A piece of software that monitors all data, exiting and entering the network and stops any potential threats
What is encryption?
Encryption is when data is translated into a code which only someone with the correct key can access encrypted text is called ciphertext
