#4 Networks & the Effects of Using Them

Networks

IP address

• Also known as Internet Protocol address

• A unique number assigned to a device on a network

MAC address

• Also known as Media Access Control address

• A unique identifier assigned to a NIC (Network Interface Card)

• It is a hardware address and doesn’t change, unlike an IP address

Router

• A device that enables data to be sent between different types of networks

  • It consults routing tables to know where to send the data

• It can be connected through cables or wirelessly to connect a LAN (Local Area Network) to the internet

• Uses:

  • connecting networks and devices to the internet

  • storing computer addresses

  • routing data packets

• Data packet received → Router checks destination → If for local network, sent to local switch/hub → If for another network, sent to relevant router

A WAN (Wide Area Network) covers a large geographical area, like the internet.

A WLAN (Wireless Local Area Network) connects devices wirelessly within a small area like a building.

Data Packet

• A small chunk of data sent over a network

• It includes the data and control details like destination, source, and error-checking bits

Common Network Devices

Network Interface Card (NIC)

• Enables a device to connect to a network

• Converts binary data into electrical signals

• Usually built into the motherboard

• Each NIC has a unique MAC address

Hubs

• Connect multiple devices to form a LAN

• Send incoming data packets to all connected devices

• Disadvantages: insecure and causes unnecessary network traffic

Switches

• Smarter hubs that form LANs

• Store devices’ MAC addresses in a lookup table

• Send data only to the intended device

• Advantages: better security and efficiency.

Summary (Hubs vs Switches):

Bridges

• Connect two LANs using the same protocol

• Use MAC addresses to forward data

• Cannot connect to external networks (unlike routers)

Comparison:

Wi-Fi & Bluetooth

Both are used for wireless communication between devices. They both use electromagnetic radiation as the carrier of data transmission.

Bluetooth uses:

• When transferring data between 2 or more devices that are very close together.

• When the speed of data transmission isn’t crucial.

• For low-bandwidth applications.

Wi-Fi uses:

• Full-scale networks.

• When the data transfer rate is crucial.

• For uses where a higher range and better security are required.

Differences and similarities:

• Bluetooth uses a transmission frequency of 2.4 GHz, whereas Wi-Fi uses a 2.4 – 5.0 GHz range.

• Wi-Fi has a much faster data transfer rate.

• Wi-Fi has a higher geographical range in which it is effective.

• Bluetooth only allows up to 7 devices to be connected simultaneously, whereas the number of devices connected to a Wi-Fi network depends on the router/routers used.

• Bluetooth uses key-matching encryption. However, Wi-Fi uses WPA (Wi-Fi protected access) and WEP (wireless equivalent privacy).

Cloud Computing

This method is where data is stored on remote servers accessed online.

The three types of cloud storage are:

1. Public Cloud - The customer and the cloud storage provider are different companies.

2. Private Cloud - The customer and the cloud storage provider are a single organization.

3. Hybrid Cloud - Combines public and private cloud options and allows sensitive data to remain private while providing public cloud services for less sensitive information.

• Cloud data is duplicated and stored on other servers to ensure availability during system failures, upgrades, and maintenance.

Advantages:

• Services can be scaled up or down according to changing requirements.

• Cloud storage eliminates the need for a business to purchase expensive equipment for infrastructure and maintenance.

• Readily available globally, allowing both remote working and data sharing.

• Providers offer high levels of ensuring that services are always available.

• It can offer an almost unlimited amount of storage.

• A backup of the data from the cloud will allow full data recovery in case of incidents.

• Files can be synced across multiple devices.

• There is no need to carry storage devices around.

Disadvantages:

• A stable internet connection is always required.

• Data storage in clouds may be vulnerable to security breaches.

• The user depends on the storage provider for reliability and availability of services.

• The services may become expensive as the amount of storage or bandwidth required increases.

Common Network Environments

1. Internet:

• The Internet is a very large global network that consists of many other interconnected networks

• The World Wide Web is a vast collection of web pages that can be accessed using a web browser.

• The World Wide Web allows you to access information by using the internet

Characteristics:

• It is an open network, meaning everyone can access the same resources and information as everybody else.

• People from all over the world can communicate with each other in real-time.

• Available to anyone who has a suitable device and access to any one of the interconnected networks.

Uses:

• Education and training

• Social Networking

• Online shopping

• Entertainment

2. Intranet:

• Usually private and are used to send information securely and safely.

• Access to an organization’s Intranet is restricted and only accessible to authorized users such as employees.

• Intranets have many advantages over the internet, such as:

  • better bandwidth than the internet,

  • data is kept within the organization,

  • less chance of hacking and attacks,

  • administrators can manage access to external sites and links.

Characteristics:

• A private network that is accessible to employees within a company or organization.

• Usually behind a firewall to ensure security.

• Allows for document sharing and the use of collaboration tools between users.

• It can be customized to meet the specific requirements of the business.

• Users will require a username and password to access the Intranet.

3. Extranet:

• Private Intranet that also allows access by selected parties that reside outside of the organization. These parties, for example, maybe customers, key stakeholders or clients.

• Users will have an authorization level once they have successfully logged in, which will determine which resources they may access.

• Similarities between the Internet, Intranet and extranet are as follows:

  • They are all web-based technologies

  • They allow users to access information remotely

  • They all use client-server architecture

  • They all use security measures such as authentication and encryption

  • They all promote and facilitate information and resource sharing

• Differences between the internet, intranet and extranet are as follows:

  • The internet is a global network, whereas an intranet/extranet is a private network contained within an organization

  • The use of the internet covers a wide range of purposes, whereas an intranet/extranet is designed for specific users and purposes.

  • Much information is publicly available, whereas an intranet/extranet is not.

  • The Internet is not owned solely by one person or organization, whereas the organization usually owns intranets/extranets.

Network Types

1. Local Area Network (LAN): networks usually contained within a single building or small geographical location. It is made up of hubs and/or switches, which will connect several devices together. One hub or switch commonly connects to a router, allowing LAN connectivity to other outside networks such as the Internet.

Advantages:

• Allows centralized management of updates, backups and software installations.

• Can secure its devices with the use of firewalls, antivirus software and other security features to prevent unauthorized access.

• A LAN allows users on the network to share resources such as printers and other peripherals.

Disadvantages:

• The network may not function correctly in case of hardware failure.

• They are more prone to attacks than standalone computers.

• Data and peripheral accessing can be slow, based on network traffic.

• LAN networks require maintenance to ensure the software is up-to-date.

2. Wireless Local Area Network (WLAN): Local Area Networks allow devices to connect wirelessly rather than using physical cables. Wireless Access Points (WAPs) are connected to an existing wired network, which provides wireless connectivity. Support a vast range of devices, such as smartphones and laptops, are very popular in public areas such as shopping malls.

Advantages:

• Allows users to connect anywhere in the range of a Wireless Access Point (WAP).

• They can be used in various indoor and outdoor environments, making them highly flexible.

• As the requirements change, additional WAPs can be added relatively easily.

• Printer access can be given to wireless devices.

Disadvantages:

• The strength of their signals can be affected by obstacles such as walls.

• Speeds can be affected by high-traffic areas.

• It can sustain interference from other devices which can affect performance and connectivity.

• Can be vulnerable to security threats due to signal interception.

3. Wide Area Networks (WAN): is formed by several LANs connected through a router. It is expensive. However, it comes with a more enhanced security. Additional hardware is needed for a WAN: Routers, modems, and proxy servers.

Advantages:

• Provide the ability to connect geographically dispersed locations, such as offices in different cities or countries.

• Offer the flexibility to scale up or down based on the organisation's needs.

• Administrators can monitor and manage the network infrastructure from a single location.

Disadvantages:

• Setting up and maintaining a WAN can be expensive, especially compared to LANs.

• Cover larger distances and rely on public networks or leased lines, which can introduce latency and affect performance.

• WANs are subject to the reliability and availability of external service providers.

Network Issues and Communication

• Connection to a network exposes a user to:

  • Hacking: Unauthorized access given to the computer. This can lead to identity theft or the misuse of personal information.

  • Phishing: Phishing involves getting sensitive information, such as usernames, passwords, and credit card details, for malicious reasons by mimicking a reliable webpage on the network

  • Pharming: This is malicious code installed on a user’s computer or a web server; the code will redirect the user to a fake website without their knowledge (the user doesn’t have to take any action, unlike phishing).

  • Viruses: Program code that replicates (copies itself) to delete or corrupt files and cause the computer to malfunction

Passwords

It is a common form of security often accompanied by a username or email address.

• There are many ways to enhance the security of your password, such as the following:

  • Ensure that the password is changed regularly in case it has been obtained illegally or accidentally

  • Ensure that the password uses a combination of uppercase, lowercase, numbers and special characters to make the password more difficult to guess.

  • iloveict is a weak password

  • 1lov3ICT# is a strong password

• Anti-spyware software can be run regularly to ensure that your information, including your password, is not passed to an unauthorized third-party user.

Other Authentication Methods

1. Zero login: A security concept that eliminates traditional login methods, such as usernames and passwords, using biometrics or other authentication factors for seamless and password-less access.

2. Biometric Recognition: These authentication methods use unique physical or behavioural characteristics, such as fingerprints, iris scans, or voice recognition, to verify a person's identity.

3. Magnetic Stripes: These are authentication features on cards storing data magnetically. They enable secure identification and authorization by containing encoded information that magnetic stripe readers can read.

4. Smart Cards: Smart cards are portable devices with integrated circuits to store and process data. They are used for authentication, identification, and secure transactions in various applications such as banking, telecommunications, and access control.

5. Physical Tokens: It is a type of authentication that takes the shape of a solid object. The user demonstrates ownership of the token through interaction with a login system. Physical tokens have embedded clocks that create one-time passwords (OTPs) when a PIN and other authentication information are entered.

6. Electronic Tokens are applications that users install on their hardware, such as smartphones. Say a person wants to access a website on a tablet computer. To access this website, users must first authenticate themselves using electronic tokens. The user has already set up the electronic token app with their smartphone. The user launches the app on their smartphone when the website asks them to verify their identity. The program creates an OTP that is only good for a short period of time.

Anti-malware Software

• Anti-malware software is designed to protect devices against viruses and malicious software. It has 3 primary purposes: detect, prevent and remove malicious software. It is installed onto a computer system and will operate in the background.

Standard features of Anti-Malware software include the following:

• Comparing the scanned files against an extensive database of known threats

• Real-time scanning

• Regular updates to gather an up-to-date list of known threats

• Quarantine of infected files

  • Quarantining files allows threats to be automatically deleted.

  • Allows the user to determine if the file is a legitimate threat and not a false positive.

Heuristic Checking: Instead of relying solely on a database of known viruses, this method looks for behavioral patterns and other features in a file to identify possible risks.

Electronic Conferencing

1. Video Conferencing:

   • It is a form of audio and video communication.

   • It serves as a stand-in for face-to-face meetings between several persons who may reside abroad or in another region of the country.

   • It utilizes a network in some way and is done in real-time.

   • The basic hardware includes:

     • webcams

     • large monitors/television screens

     • microphones

     • speakers

   • The software used are:

     • webcam and microphone software drivers

     • CODEC (coder and de-coder)

     • echo cancellation software

2. Audio Conferencing:

   • Meetings held using audio technology are called audio conferencing.

   • The normal telephone network can be used for audio conferencing, frequently called a phone conference.

   • The hardware required is:

     • a computer (with built-in microphones and speakers)

     • external microphone and/or speakers

     • an internet phone

     • a standard phone

3. Web Conferencing:

   • Often known as webinars or webcasts, makes use of the Internet to enable conference calls.

   • This system makes use of numerous computers that are interconnected over the internet.

   • It operates in real-time, just like video conferencing, and enables the following meeting types:

     • business meetings to discuss new ideas

     • presentations

     • online education or training.