Provider-independent address space
A provider-independent address space (PI) is a block of IP addresses assigned by a regional Internet registry (RIR) directly to an end-user organization. The user must contract with an Internet service provider to obtain routing of the address block within the Internet.
Provider-independent addresses offer end-users the opportunity to change service providers without renumbering of their networks and to use multiple access providers in a multi-homed configuration. However, provider-independent blocks may increase the burden on global routers, as the opportunity for efficient route aggregation through Classless Inter-Domain Routing (CIDR) may not exist.
In April 2009 RIPE accepted a policy proposal of January 2006 to assign IPv6 provider-independent IPv6 prefixes. Assignments are taken from the address range 2001:678::/29 and have a minimum size of a /48 prefix.