Computer Networking Fundamentals

Study Notes

Definition: Computer networking refers to the process of connecting devices to share resources, exchange data, and communicate with each other.
Key characteristics:
- Scalability: Ability to add or remove devices as needed.
- Flexibility: Ability to connect devices of different types and manufacturers.
- Reliability: Ability to maintain connections and data transfer even in the presence of errors or failures.

Devices:
- End devices (e.g., computers, smartphones, servers)
- Intermediary devices (e.g., routers, switches, modems)
Media:
- Wired media (e.g., copper cables, fiber optic cables)
- Wireless media (e.g., radio waves, infrared)
Protocols:
- Communication languages that govern data transmission and reception (e.g., TCP/IP, HTTP, FTP)

Unmanaged Switches:
- Simple, plug-and-play devices that forward data based on MAC addresses.
- No configuration or management capabilities.
Managed Switches:
- Allow configuration and management of network traffic, VLANs, and Quality of Service (QoS).
- Support for SNMP, console, and web-based management.
Smart Switches:
- Mid-level devices that offer some management capabilities, but not as advanced as managed switches.
- Often used in small to medium-sized networks.

Definition: A unique identifier assigned to each device on a network to facilitate communication.
Types:
- IPv4 (32-bit): 192.0.2.1 (dotted decimal notation)
- IPv6 (128-bit): 2001:0db8:85a3:0000:0000:8a2e:0370:7334 (hexadecimal notation)
IP Address Components:
- Network ID (NetID): Identifies the network portion of the IP address.
- Host ID (HostID): Identifies the device portion of the IP address.
- Subnet Mask: Determines the scope of the network and host IDs.
- Default Gateway: The IP address of the router that connects the network to other networks.

Computer networking is the process of connecting devices to share resources, exchange data, and communicate with each other.
Key characteristics of computer networking include scalability, flexibility, and reliability.

Devices in a network include end devices (e.g., computers, smartphones, servers) and intermediary devices (e.g., routers, switches, modems).
Media types in a network include wired media (e.g., copper cables, fiber optic cables) and wireless media (e.g., radio waves, infrared).
Protocols are communication languages that govern data transmission and reception, examples include TCP/IP, HTTP, and FTP.

Unmanaged switches are simple, plug-and-play devices that forward data based on MAC addresses, with no configuration or management capabilities.
Managed switches allow configuration and management of network traffic, VLANs, and Quality of Service (QoS), and support SNMP, console, and web-based management.
Smart switches offer some management capabilities, but not as advanced as managed switches, and are often used in small to medium-sized networks.

An IP address is a unique identifier assigned to each device on a network to facilitate communication.
There are two types of IP addresses: IPv4 (32-bit) and IPv6 (128-bit).
IPv4 addresses are written in dotted decimal notation (e.g., 192.0.2.1).
IPv6 addresses are written in hexadecimal notation (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334).
An IP address consists of a Network ID (NetID), Host ID (HostID), Subnet Mask, and Default Gateway.
The Network ID (NetID) identifies the network portion of the IP address.
The Host ID (HostID) identifies the device portion of the IP address.
The Subnet Mask determines the scope of the network and host IDs.
The Default Gateway is the IP address of the router that connects the network to other networks.

Plus Switches (also known as managed switches) offer advanced features, including:
- Configurability and monitoring using Simple Network Management Protocol (SNMP)
- Support for Virtual Local Area Networks (VLANs) and spanning tree protocol
- Traffic prioritization using Quality of Service (QoS)
- Often used in large-scale networks and data centers

Power over Ethernet (PoE) switches provide power to devices over Ethernet cables, eliminating the need for separate power supplies and cables
Support devices such as IP phones, cameras, and wireless access points
Can power devices up to 90W
Available in various types, including PoE (15.4W), PoE+ (30W), PoE++ (60W), and UPoE (90W)

Network topology refers to the physical and logical arrangement of devices in a network
Common network topologies include:
- Bus Topology: A single cable connects all devices in a linear sequence
- Star Topology: Devices connected to a central device (hub or switch)
- Ring Topology: Devices connected in a circular configuration
- Mesh Topology: Each device connected to every other device
- Hybrid Topology: Combination of two or more topologies
Topology affects network performance, scalability, and reliability