Virtual Aggregation as specified in [I-D.ietf-grow-va] requires
configuration of a static "VP-List" on all routers. The VP-List
allows routers to know which prefixes may or may not be FIB-
installed. This draft specified an optional method of determining
this that requires far less configuration. Specifically, it requires
the configuration of a "VP-Range" in ASBRs connected to transit and
peer ISPs. A Non-transitive Extended Communities Attribute is used
to convey to other routers that a given route can be FIB-suppressed.