IP anycast is a powerful IP addressing mode that can be used for service discovery as well as direct support of RPC-like services (for instance DNS) and connectionless network services (for instance IPv6 transition). In spite of its potential usefulness, IP anycast is not widely deployed. We believe the primary reason for this is the difficulty of deployment. While IP anycast does not require changes to router software, it does require obtaining an IP address block and router configuration.
We propose a Proxy IP Anycast Service (PIAS) that would make it easy for end-users to deploy anycast-based services. With PIAS, IP anycast is deployed once as an infrastructure service. IP anycast destinations simply register with the nearest anycast proxy (which is discovered through IP anycast!), and a tunnel is formed from the proxy to the anycast destination (NAT'ing is used to support legacy destinations). We have implemented PIAS and are in the process of deploying it.
Paul Francis, Professor