أنواع الشبكات: نظرة عامة

• A network is a system of interconnected devices that communicate with each other to share resources and information.
• Networks range from simple home setups to complex global infrastructures like the internet.

Geographic Coverage

• Networks are categorized based on their geographic reach.
• Types range from Personal Area Networks (PAN) that connect personal devices to Global Area Networks (GAN) that encompass international connections.
• Each type serves distinct purposes based on size and scope.

Personal Area Network (PAN)

• PANs are the smallest type of network, typically covering a radius of a few meters.
• They enable communication between personal devices like smartphones, tablets, and laptops.
• They often use Bluetooth or USB connections.

Local Area Network (LAN)

• LANs cover a small geographic area, such as an office, home, or school.
• They are typically connected via Ethernet.
• LANs facilitate high-speed data transfer between connected devices and support file sharing and internet connectivity.

Metropolitan Area Network (MAN)

• MANs connect multiple LANs within a city or large campus.
• They often utilize high-speed connections like fiber optics.
• MANs serve businesses needing efficient communication over short distances without relying on the wider internet.

Wide Area Network (WAN)

• WANs cover large geographic areas, often linking multiple LANs over long distances.
• The most prominent example of a WAN is the internet.
• WANs facilitate global connectivity, communication, and resource sharing across vast locations.

Global Area Network (GAN)

• GANs extend beyond national boundaries, combining various WANs to create an interconnected network.
• GANs facilitate global telecommunications and data transfer, critical for international businesses and organizations.

Functionality: Client-Server Network

• In a Client-Server network, a central server manages resources and services.
• This allows multiple client devices to interact efficiently.
• This model supports resource sharing, data storage, and security protocols effectively.

Functionality: Peer-to-Peer (P2P) Network

• P2P networks allow devices to share resources directly without a central server.
• This enables equal participation among users.
• This flexibility is often utilized in file-sharing applications and collaborative projects.

Communication Medium: Wired Networks

• Wired networks employ physical cables, such as Ethernet or fiber optics, to establish connections between devices.
• Wired networks provide stable and high-speed communication.
• Wired networks are ideal for environments requiring reliability.

Communication Medium: Wireless Networks

• Wireless networks utilize radio waves to connect devices, offering flexibility and mobility.
• Common types include Wi-Fi and Bluetooth, allowing seamless communication without physical connections.

Confidentiality

• Confidentiality ensures that sensitive information is accessed only by authorized users.
• Employing techniques like encryption and access controls helps maintain the privacy of data within networks.

Integrity

• Integrity guarantees that data remains accurate and unaltered during transmission.
• Mechanisms like checksums and hash functions help detect unauthorized modifications to vital information.

Availability

• Availability ensures network resources are accessible when needed.
• Implementing redundancy and failover systems is essential for minimizing downtime and ensuring seamless access to information.

Firewalls

• Firewalls act as barriers between trusted and untrusted networks.
• They filter incoming and outgoing traffic.
• They are vital for protecting internal networks from potential cyber threats and unauthorized access.

Encryption

• Encryption transforms data into a coded format, making it unreadable to unauthorized users.
• Strong encryption protocols, such as SSL/TLS, are essential for securing data in transit across networks.

Access Control

• Access control regulates who can view or use network resources.
• Implementing robust policies and multi-factor authentication enhances security by ensuring that only authorized individuals access sensitive information.

Antivirus & Anti-malware

• Antivirus and anti-malware software are critical for detecting and removing malicious software.
• Regular updates and scans ensure that networked devices remain protected against evolving threats.

Common Network Threats

• Common network threats include malware, phishing, and denial-of-service attacks.
• Understanding these threats is crucial for developing effective security measures and maintaining a secure network environment.

Mitigation Strategies

• Mitigation strategies, including regular software updates and user education, are vital for maintaining network security.
• Strong password policies and multi-factor authentication further reduce the risk of breaches.