IPv6 Addressing

These addressing types and methods define how devices are identified and communicate in IPv6 networks, offering scalability, flexibility, and improved routing.

Address Type

Description

Use Case

Anycast Addressing

Allows multiple interfaces to share the same address. Used for nearest-node routing and load balancing.

Efficient routing to the closest of multiple nodes.

CIDR (Classless Inter-Domain Routing)

Method for IP address aggregation and efficient routing. Simplifies subnetting and reduces routing table size.

Hierarchical address allocation and subnet management.

Multicast Addressing

Enables sending packets to multiple destinations simultaneously. Used for streaming, group communication, and service discovery.

Group communication in local or wide area networks.

Subnetting IPv6

Divides IPv6 networks into smaller subnetworks. Improves address organization and traffic management.

Network segmentation and management.

Unicast Addressing

Unique address assigned to a single interface. Used for one-to-one communication.

Direct communication between individual devices.

RFC: RFC 4291

Main Features:

  • Multiple interfaces share the same IP address

  • Packets routed to the nearest interface (in terms of routing cost)

  • Used for load balancing and redundancy

Use Cases:

  • Efficient routing to the closest of multiple nodes (e.g., DNS servers, gateways)

Alternative Approaches:

  • Unicast addressing – One-to-one communication

  • Multicast addressing – One-to-many communication

Let us learn more about Anycast Addressing:

Jump to “Anycast Addressing”

RFC: RFC 4291

Main Features:

  • Supports aggregation of IP address prefixes

  • Enables variable-length subnet masking

  • Reduces routing table size and improves scalability

Use Cases:

  • Hierarchical address allocation and subnet management

  • Simplifies routing and address delegation

Alternative Approaches:

  • Classful addressing (obsolete)

Let us learn more about CIDR:

Jump to “CIDR”

RFC: RFC 4291

Main Features:

  • Enables one-to-many communication

  • Replaces broadcast in IPv6

  • Uses address range ff00::/8

  • Used for service discovery and protocol announcements

Use Cases:

  • Group communication in LAN/WAN

  • Streaming, routing protocol updates, neighbor discovery

Alternative Approaches:

  • Broadcast addressing (IPv4 only)

  • Anycast addressing – One-to-nearest communication

Let us learn more about Multicast Addressing:

Jump to “Multicast Addressing”

RFC: RFC 4291, RFC 7421

Main Features:

  • Divides IPv6 prefixes into smaller subnets

  • Recommended subnet size is /64

  • Helps with traffic control and address hierarchy

Use Cases:

  • Network segmentation in enterprise/ISP networks

  • Security policy enforcement

Alternative Approaches:

  • Flat addressing schemes (rare)

Let us learn more about Subnetting IPv6:

Jump to “Subnetting IPv6”

RFC: RFC 4291

Main Features:

  • Unique address assigned to a single interface

  • Includes global, link-local, and unique local types

  • Enables device-to-device communication

Use Cases:

  • One-to-one communication on IPv6 networks

  • Device identification, routing, and connectivity

Alternative Approaches:

  • Anycast addressing – One-to-nearest communication

  • Multicast addressing – One-to-many communication

Let us learn more about Unicast Addressing:

Jump to “Unicast Addressing”