1.1 Networking Concepts

Key Concepts

• Network Topologies
• Network Protocols
• IP Addressing
• Subnetting
• Network Devices

Network Topologies

Network topologies define the arrangement of various elements (links, nodes, etc.) in a computer network. Common topologies include:

• Bus Topology: All devices are connected to a central cable, known as the bus or backbone. Example: Early Ethernet networks.
• Star Topology: All devices are connected to a central hub or switch. Example: Modern Ethernet networks in homes and offices.
• Ring Topology: Each device is connected to two other devices, forming a ring. Example: Token Ring networks.
• Mesh Topology: Each device is connected to every other device. Example: Military communication networks.

Network Protocols

Network protocols are a set of rules and conventions for transmitting data between network devices. Key protocols include:

• TCP/IP: The foundational protocol suite for the internet. Example: HTTP, FTP, and SMTP.
• HTTP/HTTPS: Used for web browsing. Example: Accessing a website like www.example.com.
• DNS: Translates domain names to IP addresses. Example: When you type "www.google.com" into your browser, DNS resolves it to an IP address.
• FTP: Used for transferring files between systems. Example: Uploading a file to a web server.

IP Addressing

IP addresses are unique identifiers assigned to each device connected to a network. There are two main versions:

• IPv4: Uses 32-bit addresses, represented in dotted-decimal format (e.g., 192.168.1.1). Example: Home router IP address.
• IPv6: Uses 128-bit addresses, represented in hexadecimal format (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334). Example: Future-proofing the internet as IPv4 addresses run out.

Subnetting

Subnetting is the process of dividing a network into smaller, more manageable subnetworks. It helps in efficient IP address management and improves network performance. Example:

• A Class C network (192.168.1.0/24) can be subnetted into two subnets: 192.168.1.0/25 and 192.168.1.128/25.

Network Devices

Network devices are hardware components that facilitate communication between devices on a network. Key devices include:

• Router: Connects multiple networks and routes data packets between them. Example: Home router connecting your devices to the internet.
• Switch: Connects devices within a single network, forwarding data only to the intended recipient. Example: Ethernet switch in a small office.
• Hub: Connects multiple devices in a network, but broadcasts data to all connected devices. Example: Early Ethernet hubs.
• Firewall: Protects a network by filtering incoming and outgoing traffic based on security rules. Example: Corporate firewalls protecting internal networks.