IPv6 Networking and Stateless Addressing

Overview

• IPv6 incorporates techniques from IPv4, updated for modern networks.
• Includes DHCP for IPv6, similar to IPv4, but with enhancements for redundancy and enterprise use.

IPv6 Address Assignment

• Stateless Addressing:
  • IPv6 allows devices to self-assign IP addresses without DHCP servers.
  • Known as Stateless Address Autoconfiguration (SLAAC).
  • No need to track IP or MAC addresses.
  • No lease time, thus no need to release IP addresses.

Neighbor Discovery Protocol (NDP)

• Replaces ARP in IPv6 networks.
• Uses multicast instead of broadcast for efficient communication.

Functions of NDP

• Router Discovery:

  • Devices use Router Solicitation to find local routers.
  • Routers can send unsolicited Router Advertisements to all devices.
  • Provides subnet, prefix, DNS server, and other IPv6 configuration.

• Duplicate Address Detection (DAD):

  • Ensures no duplicate addresses exist on the network.

Stateless Address Autoconfiguration (SLAAC)

1. Subnet Discovery:

   • Uses NDP to identify the local subnet through Router Solicitation.
   • Router responds with Router Advertisement including prefix info.

2. Interface ID Creation:

   • Last 64 bits of the IPv6 address.
   • Often derived from a modified MAC address with inserted 'FFFE'.
   • Alternatives include using a randomly generated value.

3. Address Verification:

   • Uses NDP's DAD to verify the uniqueness of the assigned address.

Conclusion

• Devices gain a unique, routable IPv6 address without needing a DHCP server.
• Efficient and automated address management process in IPv6 networks.