BD

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