Networking Today
Networks have revolutionized modern life by enabling global communication,
connecting people across vast distances, and fostering worldwide
communities.
Network Components
Networks consist of three main components: end devices, intermediary
devices, and network media.
1. End Devices:
○ Source or destination of data (e.g., computers, smartphones,
printers, servers).
○ Example: Your computer sends an email, and the recipient's
device receives it.
2. Intermediary Devices:
○ Connect and manage data flow between end devices.
○ Examples:
■ Switches: Connect multiple devices within a LAN.
■ Routers: Direct data between networks, finding thebest
path.
■ Firewalls: Control and secure network traffic.
■ Wireless Access Points (WAPs): Connect wireless
devices to a wired network.
○ Functions:
■ Regenerate data signals for reliable transmission.
■ Maintain and manage data pathways.
■ Detect and notify errors, enhancing network reliability.
, 3. Network Media:
○ The medium through which data travels.
○ Types:
■ Copper Cables: Transmit data using electrical impulses.
■ Fiber-Optic Cables: Use light for high-speed,
long-distance transmission.
■ Wireless: Transmit data via radio waves.
Common Types of Networks
Networks are categorized by their size, geographic spread, and functionality.
1. Local Area Network (LAN):
○ Covers small areas like homes, offices, or schools.
○ Offers high-speed, controlled communication.
2. Wide Area Network (WAN):
○ Spans large areas, connecting multiple LANs.
○ Managed by various organizations; the internet is the largest
WAN.
3. The Internet:
○ A vast global network of interconnected LANs and WANs.
○ Relies on copper, fiber-optic, and wireless connections.
○ Governed by organizations like IETF, ICANN, and IAB.
Cisco IOS Basics
Cisco IOS (Internetwork Operating System) is used for configuring network
devices.
, 1. Accessing Cisco IOS
(video tutorialhttps://www.youtube.com/watch?v=BK7vepX19_g)
○ Shell:CLI or GUIinterface for interacting with devices.
■ CLI (Command Line Interface):CLI is a text-based
interface where users interact with the computer by typing
commands. It's powerful and efficient, allowing for precise
control over the system. Users need to know the correct
commands and syntax, which can make it less intuitive for
beginners.
■ GUI (Graphical User Interface):GUI uses visual
elements like windows, icons, and buttons to allow users to
interact with the computer. It's user-friendly and intuitive,
making it accessible for all skill levels. However, it can be
less efficient for complex tasks compared to CLI.
○ Kernel: Manages hardware-software communication.
○ Access Methods:
■ Console: Direct physical connection for setup.
■ SSH: Secure remote access.
■ Telnet: Insecure remote access, rarely used.
2. IOS Navigation
○ User EXEC Mode (
>):Basic commands.
○ Privileged EXEC Mode (
#)
:Full access, entered with
enable
.
○ Configuration Modes:
■ Global Configuration: Device-wide settings (
configure
terminal
).
Networks have revolutionized modern life by enabling global communication,
connecting people across vast distances, and fostering worldwide
communities.
Network Components
Networks consist of three main components: end devices, intermediary
devices, and network media.
1. End Devices:
○ Source or destination of data (e.g., computers, smartphones,
printers, servers).
○ Example: Your computer sends an email, and the recipient's
device receives it.
2. Intermediary Devices:
○ Connect and manage data flow between end devices.
○ Examples:
■ Switches: Connect multiple devices within a LAN.
■ Routers: Direct data between networks, finding thebest
path.
■ Firewalls: Control and secure network traffic.
■ Wireless Access Points (WAPs): Connect wireless
devices to a wired network.
○ Functions:
■ Regenerate data signals for reliable transmission.
■ Maintain and manage data pathways.
■ Detect and notify errors, enhancing network reliability.
, 3. Network Media:
○ The medium through which data travels.
○ Types:
■ Copper Cables: Transmit data using electrical impulses.
■ Fiber-Optic Cables: Use light for high-speed,
long-distance transmission.
■ Wireless: Transmit data via radio waves.
Common Types of Networks
Networks are categorized by their size, geographic spread, and functionality.
1. Local Area Network (LAN):
○ Covers small areas like homes, offices, or schools.
○ Offers high-speed, controlled communication.
2. Wide Area Network (WAN):
○ Spans large areas, connecting multiple LANs.
○ Managed by various organizations; the internet is the largest
WAN.
3. The Internet:
○ A vast global network of interconnected LANs and WANs.
○ Relies on copper, fiber-optic, and wireless connections.
○ Governed by organizations like IETF, ICANN, and IAB.
Cisco IOS Basics
Cisco IOS (Internetwork Operating System) is used for configuring network
devices.
, 1. Accessing Cisco IOS
(video tutorialhttps://www.youtube.com/watch?v=BK7vepX19_g)
○ Shell:CLI or GUIinterface for interacting with devices.
■ CLI (Command Line Interface):CLI is a text-based
interface where users interact with the computer by typing
commands. It's powerful and efficient, allowing for precise
control over the system. Users need to know the correct
commands and syntax, which can make it less intuitive for
beginners.
■ GUI (Graphical User Interface):GUI uses visual
elements like windows, icons, and buttons to allow users to
interact with the computer. It's user-friendly and intuitive,
making it accessible for all skill levels. However, it can be
less efficient for complex tasks compared to CLI.
○ Kernel: Manages hardware-software communication.
○ Access Methods:
■ Console: Direct physical connection for setup.
■ SSH: Secure remote access.
■ Telnet: Insecure remote access, rarely used.
2. IOS Navigation
○ User EXEC Mode (
>):Basic commands.
○ Privileged EXEC Mode (
#)
:Full access, entered with
enable
.
○ Configuration Modes:
■ Global Configuration: Device-wide settings (
configure
terminal
).
