Technical Summary
This document describes a method by which a Service Provider may use
an IP backbone to provide IP VPNs (Virtual Private Networks) for its
customers. This method uses a "peer model", in which the customers'
edge routers ("CE routers") send their routes to the Service
Provider's edge routers ("PE routers"). BGP is then used by the
Service Provider to exchange the routes of a particular VPN among the
PE routers that are attached to that VPN. This bis done in a way which
ensures that routes from different VPNs remain distinct and separate,
even if two VPNs have an overlapping address space. The PE routers
distribute, to the CE routers in a particular VPN, the routes from
other the CE routers in that VPN. The CE routers do not peer with
each other, hence there is no "overlay" visible to the VPN's routing
algorithm. The term "IP" in "IP VPN" is used to indicate that the PE
receives IP datagrams from the CE, examines their IP headers, and
routes them accordingly.
Working Group Summary
There has long been consent in the WG to move this document
forward. Indeed, the original charter called from revising
RFC 2547 (informational) to reflect experience with it, and put it on
the standards track.
Protocol Quality
This document has been reviewed for the IESG by Thomas Narten. There
are numerous implementations in use.