Internet Protocol Version 6 (IPv6)

This section covers the IPv6 protocol, its routing methods, and addressing mechanisms. IPv6 resolves limitations in IPv4, such as address exhaustion, and introduces new features for more efficient networking, including simplified headers, improved multicast, and integrated security support.

Category

Description

Use Case

IPv6 Basics

Introduction to IPv6, including its address structure, packet format, and differences from IPv4. Highlights features like larger address space, simplified header, and auto-configuration.

Future-ready internet and enterprise networking.

IP Routing Protocols

Describes routing protocols adapted or designed for IPv6. Includes OSPFv3, RIPng, EIGRP for IPv6, IS-IS, and MP-BGP.

Efficient and scalable IPv6 routing in modern networks.

IPv6 Addressing

Explains IPv6 address types and assignment methods. Includes unicast, anycast, multicast, link-local, global unicast, and unique local addressing.

Device identification, service discovery, and traffic routing in IPv6 networks.

RFC: RFC 8200 (Obsoletes RFC 2460)

Main Features:

  • 128-bit address space (e.g., 2001:0db8::1) allowing trillions of unique addresses

  • Simplified and fixed-size header (40 bytes) compared to IPv4

  • No need for NAT — end-to-end connectivity and global addressing

  • Built-in support for IPsec, mobility, and auto-configuration (SLAAC)

  • Eliminates broadcast; uses multicast and anycast instead

  • Enhanced quality of service (QoS) with Flow Label field

Use Cases:

  • Modern enterprise and ISP networks

  • IoT and mobile systems requiring a large address pool

  • Future-proofing infrastructure for global internet growth

Alternative Protocols:

  • IPv4 – Legacy version still widely deployed

  • MPLS – Protocol-independent forwarding

  • IPX – Deprecated Novell protocol

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RFCs:

  • OSPFv3: RFC 5340

  • RIPng: RFC 2080

  • EIGRP for IPv6: Cisco implementation

  • IS-IS for IPv6: RFC 5308

  • MP-BGP: RFC 4760

Main Features:

  • IPv6-ready versions of major routing protocols

  • OSPFv3: - Supports IPv6 prefixes, per-link operation

  • RIPng: - UDP port 521, simple distance-vector protocol

  • EIGRP for IPv6: - Cisco proprietary, similar to EIGRPv4

  • IS-IS: - Uses TLVs for IPv6 reachability

  • MP-BGP: - Supports both IPv4 and IPv6 route advertisement

Use Cases:

  • Dynamic IPv6 routing in enterprise and ISP networks

  • Transition from IPv4 to IPv6 with dual-stack routing

  • Scalable and policy-based route distribution

Alternative Protocols:

  • Static routing – For small or controlled environments

  • IPv4 routing protocols – Used during IPv4/IPv6 coexistence

Let us learn more about IPv6 Routing:

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RFCs: RFC 4291, RFC 4193, RFC 4862, RFC 6724

Main Features:

  • 128-bit hexadecimal addresses using CIDR notation

  • Unicast: One-to-one communication

  • Multicast: One-to-many; replaces broadcasting

  • Anycast: One-to-nearest communication

  • Special addresses: - ::1 (loopback) - :: (unspecified) - fe80::/10 (link-local) - fc00::/7 (unique local) - 2000::/3 (global unicast)

  • Stateless Address Autoconfiguration (SLAAC)

Use Cases:

  • Host and router identification in IPv6 networks

  • Automatic address assignment and service discovery

  • Secure and efficient traffic routing

Alternative Protocols:

  • IPv4 – Simpler, but less scalable

  • DHCPv6 – Stateful IP assignment

  • NDP – Replaces ARP for neighbor discovery

Let us learn more about IPv6 Addressing:

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