Overview
This lecture covers the transition from IPv4 to IPv6, focusing on methods that allow both protocols to coexist and techniques for facilitating IPv6 traffic over existing IPv4 networks.
Coexistence of IPv4 and IPv6
- A complete, immediate switch to IPv6 is impractical due to the need for coordination and legacy devices.
- IPv4 and IPv6 must coexist, allowing organizations to transition at their own pace.
IPv4 Mapped Address Space
- IPv6 reserves addresses that correlate directly to IPv4 addresses.
- IPv6 addresses starting with 80 zeros followed by 16 ones are mapped to IPv4.
- The last 32 bits of these IPv6 addresses match the IPv4 address, enabling IPv4 traffic over IPv6 networks.
IPv6 Tunneling over IPv4 Networks
- IPv6 traffic must traverse IPv4 networks, especially in core internet infrastructure.
- IPv6 tunnels encapsulate IPv6 packets inside IPv4 datagrams for transport.
- Tunnel servers at each end encapsulate and decapsulate IPv6 traffic when moving through IPv4 networks.
IPv6 Tunnel Brokers and Protocols
- Tunnel brokers are companies that provide IPv6 tunneling endpoints to simplify setup.
- Multiple, competing protocols exist for IPv6 tunneling, with no clear industry standard yet.
- Tunneling is a temporary measure until native IPv6 is widely adopted.
Key Terms & Definitions
- IPv4 — Internet Protocol version 4, the original addressing protocol for the internet using 32-bit addresses.
- IPv6 — Internet Protocol version 6, the newer protocol with 128-bit addresses to replace IPv4.
- IPv4 Mapped Address Space — Special IPv6 addresses that represent IPv4 addresses to allow interoperability.
- IPv6 Tunnel — A method of sending IPv6 packets within IPv4 datagrams across IPv4 networks.
- Tunnel Broker — A service provider that sets up and manages IPv6 tunnels for users or organizations.
Action Items / Next Steps
- Review IPv6 address formatting and identify IPv4 mapped addresses.
- Research common IPv6 tunneling protocols and how tunnel brokers operate.