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.