An incremental approach to IPv6 multihoming

The availability of two or more connectivity providers (configuration known as multihoming) allows improvements in failure tolerance and enables traffic engineering capabilities. Current IPv4 multihoming solutions suffer from scalability limitations. In this article we present a solution that allow IPv6 networks to benefit from multihoming, taking advantage from the fact that each provider delegates its own set of addresses. The proposed solution consists in multiple mechanisms that provide different benefits to the multihomed site. More precisely, the solution includes a mechanism for the provision of ingress filtering compatibility, a mechanism for establishing new communications after an outage, a set of tools for traffic engineering and a protocol for preserving established communications through outages. In addition we propose a roadmap for the incremental deployment of the set of mechanisms included in the solution based on the trade-off between deployment effort required by each mechanism and the benefits obtained by the involved party. q 2005 Elsevier B.V. All rights reserved.