Networking 1

Module 1: Networking Today

1.1 Networks Affect Our Lives

• Networks connect people worldwide, enabling communication, business, and entertainment.

• The Human Network eliminates geographical boundaries.

1.2 Network Components

• Host Roles:

  • End Devices: Originates/receives data (PCs, printers, servers).

  • Servers: Provides services (web, email, file sharing).

  • Clients: Requests services from servers.

• Peer-to-Peer:

  • Devices act as both clients and servers.

  • Suitable for small networks.

• Intermediary Devices:

  • Switches, routers, firewalls manage data traffic.

• Network Media:

  • Wired (copper, fiber optic) & wireless (Wi-Fi, radio signals).

1.3 Network Representations and Topologies

• Physical Topology: Shows actual device locations.

• Logical Topology: Shows network communication paths.

1.4 Common Types of Networks

• LAN (Local Area Network): Small geographical area.

• WAN (Wide Area Network): Connects multiple LANs over long distances.

• Intranet: Private network for an organization.

• Extranet: Secure access for external users.

1.5 Internet Connections

• Home & Business Connections: Broadband, DSL, fiber, cellular.

• Converged Networks: Combines data, voice, and video.

1.6 Reliable Networks

• Fault Tolerance: Redundant paths prevent failures.

• Scalability: Supports network expansion.

• Quality of Service (QoS): Prioritizes critical data.

• Security: Prevents unauthorized access and threats.

1.7 Network Trends

• BYOD (Bring Your Own Device): Allows personal device access.

• Cloud Computing: Remote data storage and services.

• Smart Homes & IoT: Devices communicating via networks.

• Powerline Networking: Uses electrical wiring for connectivity.

1.8 Network Security

• Threats: Viruses, malware, hacking, insider threats.

• Solutions:

  • Firewalls: Blocks unauthorized traffic.

  • Antivirus software: Detects and removes threats.

  • VPN (Virtual Private Network): Secure remote access.

1.9 IT Careers & Certifications

• Cisco Certified Network Associate (CCNA): Entry-level certification.

• Networking Jobs: Roles in administration, cybersecurity, and cloud networking.

Module 2: Basic Switch & End Device Configuration

2.1 Cisco IOS Access

• Access Methods:

  • Console: Direct device connection.

  • SSH (Secure Shell): Secure remote CLI access.

  • Telnet: Insecure remote CLI access (plaintext).

  • Terminal Emulators: PuTTY, Tera Term.

2.2 IOS Navigation

• Command Modes:

  • User EXEC (>): Basic monitoring commands.

  • Privileged EXEC (#): Full device access.

  • Global Config (config): System-wide settings.

• Navigation Commands:

  • Move to Privileged EXEC: enable

  • Enter Global Config: configure terminal

  • Exit current mode: exit

  • Exit all: end or Ctrl + Z

2.3 Command Structure

• Keywords: Predefined parameters (e.g., ip protocols).

• Arguments: User-defined values (e.g., 192.168.1.1).

• Help Commands:

  • ?: Shows available commands.

  • Tab: Auto-completes commands.

  • Ctrl + C: Cancels input.

  • Ctrl + Z: Exits to Privileged EXEC.

2.4 Basic Device Configuration

• Device Naming:

  • Use hostname <name> to assign a device name.

• Password Security:

  • Enable Privileged EXEC password: enable secret <password>

  • Encrypt passwords: service password-encryption

• Banner Messages:

  • banner motd # Unauthorized Access Prohibited #

2.5 Save Configurations

• Configuration Files:

  • Startup-config (NVRAM): Saved settings.

  • Running-config (RAM): Active settings (lost on reboot).

• Save Configurations:

  • copy running-config startup-config

• Restore Last Saved Config:

  • reload

• Erase Startup Config:

  • erase startup-config

  • reload

2.6 Ports & Addresses

• IPv4 Addressing:

  • Format: 192.168.1.1 (32-bit, 4 decimal values).

  • Subnet Mask: Defines network & host portions.

  • Default Gateway: Router's IP for external access.

• IPv6 Addressing:

  • Format: 2001:db8::1 (128-bit, hexadecimal).

• Network Media Types:

  • Copper (Twisted-pair, Coaxial), Fiber-optic, Wireless.

2.7 Configure IP Addressing

• Manual Configuration (Windows PC):

  • Control Panel > Network Sharing Center > Adapter Settings > IPv4 Properties.

  • Set IP Address, Subnet Mask, Default Gateway.

• Automatic Configuration (DHCP):

  • Enable "Obtain IP address automatically."

Configure Switch Virtual Interface (SVI):
interface vlan 1

ip address <IP> <Subnet Mask>

no shutdown

2.8 Verify Connectivity

• Ping Command: ping <destination IP>

• Traceroute Command: traceroute <destination IP>

End of Study Guide