An Application of the BGP Extended Community Attribute for Distributed IPv6 Site Multihoming
This document presents for a new IPv6 site multihoming scheme and its operational requirements. It aims at solving potential deployment problems in 'IPv6 Multihoming Support at Site Exit Routers [2]' using an application of BGP extended community attribute, called multihomed community. In case of link failure in [2], basic operations to support multihoming are entirely dependent on functionality of border router in other ISPs. Hence, it causes following problems; centralized encapsulation overhead for re-routing, packet delivery along un-optimized tunneling session, and losing connectivity in case of ISP failure. Also, [2] do not provide any alternative mechanism for long-term failure. For above reasons, if the link remains failed for a long time, it has a little applicability due to previously mentioned problems. In this memo, we propose a new IPv6 site multihoming scheme, which establishes multiple direct tunneling sessions between sender's site exit router and reachable receiver's site exit router instead of one tunneling session between border router and site exit router in [2]. Furthermore, with some additional BGP operations, it can preserve connectivity of on-going sessions regardless of ISP, intermediate link, as well as directly connected site link failure.