A Proposal of Policy Routing per End-Host in IPv6 Site Multi-homing using NPTv6

Reliable Internet connectivity is essential, even for small businesses and K–12 schools. The Japanese national education program for "1 device for 1 student with a high-speed network" in schools requires highly reliable Internet access. Site multi-homing —connecting a network to multiple ISPs —is an effective solution. Routing policies in the site multi-homing are expected to be applied per end-host, ensuring optimal ISP selection and enhances network resilience. This paper proposes a policy routing method enabling per-end-host first-hop router selection in IPv6 site multi-homing with NPTv6. The core concept is to shift upstream ISP selection from source address selection to first-hop router selection, enabling control through the dynamic transmission of RAs via the RA controller. We present the control plane design of the proposed method. The paper also shows its effectiveness in small-scale environments, such as site multi-homing without BGP, based on evaluations using the prototype system.