4.9.2.3 Wireless networking Flashcards
What is WiFi?
Wireless local area network based on international standards used to enable devices to connect to a network
Used to enable devices to connect to a network
wirelessly.
What are the advantages and disadvantages of wireless and wired connection?
Wireless doesn’t need cables so you can work anywhere within range and people can easily connect.
Wireless is less secure because other people may try to connect and the signal can be poor and slower.
Wireless is more prone to interference
Why is WiFi often chosen over Bluetooth?
You can secure WiFi - WEP / WPA
Strong encryption of data
With WiFi it will only allow certain MAC addresses to connect
What are the security threats of networking?
Viruses - malicious self-replicating programs that attach to other programs
Spam - unsolicited junk email
Worms - malicious programs that replicate across networks
Trojan - malicious program hidden within a program
Phishing - misdirecting users to a fake website
Spyware - program that collects user’s information
DoS attack - repeated requests over internet overwhelm network
How are security threats dealt with in networking?
Regularly install security patches and update software Virus checking software kept up to date Anti-spyware software Firewall to control traffic Spam filter in email White lists/ black lists Strong passwords Encrypting data Logging files Employing a network manager
What is a firewall?
Blocking access from the private network to the internet, restricting certain access to the server.
Blocking connections on unwanted ports and closing ports so users can’t connect.
Preventing unauthorised access
What are the problems with spam?
Spam can take up a lot of space which may cause people to have to change their email address or their legitimate emails get lost. Filters can reject legitimate emails
Wastes time and could cause corruption or damage to software and data by viruses. Spam can be fraudulent and trick people. It slows down the internet and means customers have to pay more to their ISPs
Phishing emails can extract personal and financial information from vulnerable people
How is spam restricted?
Using multiple email addresses
Using spam black lists to block known spam email addresses
Use a spam filter
What are the steps in the CSMA/CA protocol?
When a node receives a packet of data it checks the channel the packet will be sent through is clear using a RTS (request to send) signal. If the node receives a CTS (clear to send) signal the packet is sent, if not the protocol waits for a specified amount of time and checks the channel again. This is to try and avoid collisions between packets before they are sent.
What is a SSID and how does disabling it improve security?
The name of the wireless network, given by the ISP but can be set by the user. Can cause issues if two nearby wifi networks have the same name.
The router broadcasts the SSID and security options so that devices can connect to it
The SSID/Service Set Identifier of the network will not be visible when trying to connect to a network; this means that only users who know the SSID of the network can try to connect;
What components do you need for WiFi?
What other ways can devices be connected?
Wireless network adapter.
Wireless access point.
Using coaxial cables, optical fibre, wireless, bluetooth, serial/parallel
How is WiFi encrypted?
WEP - control security on wireless network. Every packet sent over the network is encrypted with a password unique to the user. Every packet you send is encrypted with the same password which means they can be decrypted easily using algorithms after examining enough packets
WPA (WiFi Protected Access) - every packet is encrypted with a different password, so it’s more secure
What is a MAC address?
A MAC/Media Access Control address is unique to every NIC/Network Interface Card so that Each piece of networking hardware has a unique identifier
A white list only allows those MAC addresses that have been authorised to connect to the network
Blacklist MAC addresses you don’t want to connect
What is a LAN?
Local Area Network are where computers are linked together over a small geographical area.
This makes maintenance of software or files easier and workers are easy to monitor, and backup is simplified
Why are LANs sometimes segmented?
Reduces network congestion by removing collisions as less computers are connected together
Improves security because packet transmission is in a smaller section
Improves reliability as if there’s a cable failure it’s reduced to a smaller segment
