NET 101

• Requirements for Internet Connection


  • Physical Connection
  • Logical Connection
  • Applications
• Physical Connection


  • Establishing connectivity via modem, router, or LAN card
• Modem


  Converts digital signals to analog for telephone line connectivity
• Router


  Directs data packets between networks
• LAN Card


  Provides network communication capabilities to PCs
• Logical Connection


  Utilizing standards or protocols such as TCP/IP
• Applications


  Interpreting data and displaying information through web browsers, FTP, etc.
• Network Interface Card (NIC)


  Provides network communication capabilities, often integrated into motherboard slots
• External NICs


  • Available for expansion
• Types of Modems


  • PC Card Modem
  • Internal Modem
  • External Modem
• Evolution of Modem Speed


  Modem speeds evolved from 300 bps in the 1960s to Mbps in the 2000s due to technological advancements and user demands
• Historical context: Evolution of modem speeds from 300 bps to 56 kbps and beyond
• TCP/IP


  Protocols that enable resource sharing across networks
• TCP/IP configuration is similar across Windows and Mac operating systems
• TCP (Transmission Control Protocol)


  Ensures reliable data delivery
• IP (Internet Protocol)


  Handles packet routing
• Testing Connectivity with PING


  Ping verifies IP address existence and responsiveness using ICMP Echo Request datagrams
• Ping Commands


  • Internal Loopback Test
  • Host PC Ping
  • Default Gateway Ping
  • Remote Destination Ping
• IP Address


  A 32-bit address used to uniquely identify a computer on a network
• Network ID


  Identifies the network where the computer sits
• Host ID


  Uniquely identifies the computer on its network
• Network Mask


  Assigned to computers, where some bits represent a network, and others identify a particular computer
• Rules for IP Addressing


  • Restrictions on the first octet
  • Host ID values
  • Definitions of network and broadcast IDs
  • 127 range reserved for diagnostics (loopback address)
  • Host ID cannot be all 0's or all 255's
• Network ID


  A numeric/symbolic address that uniquely distinguishes a network node or device over a computer or telecommunications network
• Broadcast ID


  A special IP address used to transmit messages and data packets to network systems
• Subnetting


  • Divides larger networks for efficiency, traffic control, and improved security
• Purposes of Subnetting


  • Control network traffic
  • Segregate flow of network traffic between hosts
  • Regulate IP traffic
  • Improve network security and performance
• Why Subnetting?


  • Addresses scalability and routing table efficiency
  • Reduces network congestion
  • Enhances security by segmenting traffic
• How to Subnet


  Determine subnet mask, calculate subnets, assign addresses, and configure routers/interfaces
• Types of Subnetting Problems


  • Subnetting when given a required number of networks
  • Subnetting when given a required number of clients
  • Given an IP address & Subnet Mask, finding original network range (reverse engineering a subnet problem)
• OSI Model


  A conceptual framework developed by the International Standards Organization (ISO) to standardize network communications
• OSI Model established


  Late 1970s
• Layers of the OSI Model


  • Physical
  • Data Link
  • Network
  • Transport
  • Session
  • Presentation
  • Application
• OSI Model


  • Consists of seven layers, each with specific functions, facilitating end-to-end communication between different systems
• Understanding the OSI Model provides a structured approach to designing, troubleshooting, and maintaining network systems
• TCP/IP Protocol Suite


  The foundation of modern networking, powering communication across the Internet and other networks
• Layers of the TCP/IP Protocol Suite


  • Application
  • Transport
  • Internet
  • Link
• TCP/IP Protocol Suite


  • Provides a hierarchical structure with interactive modules, offering flexibility and scalability in network design and implementation
• Key protocols in the TCP/IP Protocol Suite


  • TCP (Transmission Control Protocol)
  • UDP (User Datagram Protocol)
  • IP (Internet Protocol)
• TCP/IP's modular architecture and robust protocols contribute to its widespread adoption and use in diverse networking environments, from local area networks (LANs) to the global Internet