Routing IPv4 packets using IPv6 next-hops has been around for some time now. It offers great opportunities to reduce IPv4 address usage in the distribution and access layer, and enables providing IPv4 as a pure add-on, keeping a clean IPv6 address structure underneath.
Despite its benefits, major challenges for deploying IPv4-with-IPv6 next-hops in practice persist. While, e.g., BGP supports such routes using RFC8950, many other IGPs still lack support. Other major issues are 'the last mile', i.e., auto-configuring clients (or, for this use-case, more likely servers), and the impact of IPv4-with-IPv6 next-hop usage on traceroutes.
In this talk, we will go over some current developments in these areas, which should make IPv4-with-IPv6 next-hops a viable option for practical deployments in the coming years. We will also expand further on possible deployment scenarios, where IPv4-with-IPv6 next-hops can remove further legacy Layer-2 infrastructure, e.g., LACP.
Tobias is a researcher at TU Wien, broadly working on everything related to the Internet; From pushing packets to the people getting the packets pushed. Besides his academic work, he enjoys running networks in his free time.