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Understanding IPv4 and IPv6 Addressing

Feb 5, 2025

Lecture Notes on IPv4 and IPv6

Introduction

  • IPv4: Primary protocol for most network communications today.
  • IPv6: Newer version of IP, supported by most major operating systems alongside IPv4.
  • Devices can have both IPv4 and IPv6 addresses, allowing communication with other internet devices using either protocol.

IPv4 Addresses

  • Consist of four separate numbers separated by periods (e.g., 192.168.1.131).
  • Binary representation: 32 total bits, divided into four 8-bit segments (octets).
    • Example: 192 in binary is 11000000.
    • Maximum value per octet is 255 (all bits set to one).
  • Limitations: Limited number of addresses due to 32-bit structure.

IPv6 Addresses

  • Designed to overcome IPv4 limitations with a 128-bit address length.
  • Supports a vast number of addresses, enough for the global population.
  • Structure: Eight groups of 16 bits each, represented in hexadecimal format.
    • Example: fe80::5d18:652:cffd:8f52.
    • More complex, harder to memorize compared to IPv4.
  • Importance of DNS: Critical for name-to-IP address conversion due to IPv6 complexity.
  • Commonly assigned with a 64-bit subnet mask.
    • First 64 bits: Network address.
    • Last 64 bits: Host address.

IP Address Assignment

  • Essential configuration parameters:
    • IP Address: Unique for each device.
    • Subnet Mask: Defines the subnet for the device (e.g., 255.255.255.0).
      • Used to determine the network portion of an IP address.
    • Default Gateway: Router IP to communicate outside the local subnet (e.g., 192.168.1.1).
  • DNS Server: Converts domain names to IP addresses.
    • Example configurations: 8.8.8.8 and 8.8.4.4 (Google DNS).
    • Importance of assigning multiple DNS servers for redundancy.

Summary

  • Understanding IP addressing is crucial for network communication.
  • With the transition to IPv6, DNS plays an even more vital role in managing complex addresses.
  • Basic network configurations include IP address, subnet mask, default gateway, and DNS settings.