Networks Flashcards
Risks and benefits of a computer network
Risks
- Viruses can spread from one device to another.
- If shared resources are lost then this will effect the whole network.
- Greater risk of hacking. Computers can be hacked easily if connected to the internet.
Benefits
- Can share resources eg, applications and printers.
- Allows for easy communication between devices eg, files are transferred quickly.
- Allows for easy network management.
- Easy to backup data onto a central server.
Define a computer network
a set of computers are connected to one another so they can communicate and share resources
Explain a PAN
Personal area network
- set up around an individual
- allows multiple devices to be connected
- eg, bluetooth
Explain a LAN
Local area network
- small geographical area
- ranges over a small organisation
- eg, schools, universities
Define a network protocol
a set of rules that allow computers to communicate and exchange information over a network.
What is a bus topology and explains its pros and cons
Connected from one cable
Pros
- easy and cheap to install
- easy to add more computers
Cons
- If main cable fails whole network fails
- less secure data
- slower as there are more collisions when data is shared
Advantages and disadvantages of wireless networks
Benefits
- Not constrained by cable.
- Cheaper
- Easier to set up
- Allows mobility
Disadvantages
- Data can be intercepted more easily
- Slower than wired methods
- Signal can be physically stopped or slowed down by walls, etc.
- Maintaining security is more challenging,
Advantages and disadvantages of wired networks
Advantages
- Generally faster to transfer data
- Less likely to suffer from interference
- Harder to hack
- Direct, more reliable connection
Disadvantages
- Expensive to install
- Requires more wiring
- May be hard to set up without knowledge of the network
What are the four layers of the TCP/IP structure and what are their purposes?
Application layer
-Changes message into a form that is understood by the sender and recipient devices.
Transport layer
- Breaks down message into smaller packets.
- Each packet is given a packet number.
- The receiver uses this to assemble the packets in the correct order and allows them to see if any are missing.
Internet layer
- Adds senders IP address
- Network then knows where to send the message.
Link layer
-Enables transfer of packets between devices connected on a network
What is a star topology and explains its pros and cons
Connected to a central hub or switch Pros - greater security - if connections fail only one computer will be affected - fewer collisions
Cons
- If central hub fails whole network crashes
- expensive to install, extra cables
Name and describe the network protocols
HTTP/S (Hypertext transfer protocol/secure) - governs communication between web server and client, includes security in websites
TCP - Transmission Control Protocol - enables communication over the internet
FTP - File Transfer Protocol - governs transmissions of files across networks and internet
UDP - User Datagram Protocol - messages are sent instead of packets
Name and describe an addressing protocol
IP - Internet Protocol - adds addresses onto packets to send
Name and describe an email protocol
SMTP - Simple Mail Transfer - used by mail servers to send and receive mail
IMAP - Internet Message Access - controls the download/upload of emails to and from the mail server
Network security
Firewall
-A firewall is software that will block unexpected connections coming in to the network.
Encryption
-Encoding data so that it cannot be understood by anyone other than its recipient.
Authentication
- Authentication is when a user has to confirm that they are who they say they are on a computer system.
- Biometrics, passwords/pins, usernames and passwords
MAC Address filtering
- Whitelist = only specific devices are allowed to access the network.
- Blacklist = devices that are banned from a network.
Why is network security important?
It helps protect peoples data so its safe and secure
It prevents threats from entering the system
