IPv6: The Future of the Internet

Introduction

• IPv6 Usage: Widely used, especially on cellular networks.
• Motivation: Address the limitations of IPv4.

IPv4 Limitations

• Originally allocated ~4.2 billion addresses.
• Address shortage due to the proliferation of internet-connected devices.
• Temporary solutions: Network Address Translation (NAT).

IPv6 Advantages

• Address Space: 128-bit addresses, providing 340 undecillion possible addresses.
  • Example Comparison: Enough to give devices to every bacteria on Earth and more.

IPv6 Address Structure

• Consists of eight segments called hextets.
• Uses colons to separate hextets, unlike dots in IPv4.
• Hexadecimal System: Values range from 0 to F.

Binary Conversion

• Each digit in a hextet represents 4 bits.
  • Example: 'D' = 13 in decimal, '1101' in binary.

IPv6 Subnetting

• Network and Host Sections: Typically split in half.
• Uses a prefix length (e.g., /64) instead of a subnet mask.

Shortening IPv6 Addresses

• Zero Compression: Groups of zeros can be replaced with a double colon (::).
• Leading Zero Compression: Remove leading zeros within hextets.
• Limitations: Compression can only be applied once.

IPv6 Address Types

• Global Unicast: Similar to IPv4 public addresses.
• Link-Local Addresses: Used for local communication, not routable.
  • Prefix: fe80::/10
• Loopback: For testing without network connection.
• Unspecified: Absence of an address, represented by ::.
• Unique Local: Similar to IPv4 private addresses.
  • Prefix: fc00::/7
• Embedded IPv4: Represents IPv4 in the IPv6 space for compatibility.
• Multicast Addresses: Efficient group communication, starts with FF.
• Anycast: Same address assigned to multiple devices, data sent to closest.

Security

• IPsec: Built-in to IPv6, providing optional authentication and encryption.
  • Requires activation by users and administrators.

Conclusion

• IPv6 is designed to support the growing number of internet-connected devices efficiently.
• Offers improvements in address space and network management over IPv4.