A survey of IPv6 site multihoming proposals

Abstract

Site multihoming is a method by which an Internet end-site, for example an enterprise network, may connect to multiple service providers simultaneously. There are many reasons why multihoming is desirable, e.g. service resilience, network load balancing or provider independence. In the IPv4 Internet, multihoming has been achieved by use of relatively simple techniques, including networks advertising their network prefixes - whether such prefixes are independent of the Internet Service Providers (ISPs) or not - to the Internet global routing infrastructure. With the introduction of IPv6 the vast increase in the number of potential site prefixes means that for scalable site multihom- ing we cannot repeat such IPv4 multihoming practices. Thus new IPv6 multihoming solutions are required. In this paper we present an overview of currently proposed solutions and explore the challenges and motivations of site multihoming. Such a review is timely because multihoming remains a key perceived obstacle to widespread IPv6 deployment in mission-critical environments.