This MIB module defines objects describing selective
VRF download.  The selective VRF download feature makes
a best effort to download only those prefixes and labels
to a physical entity required to forward traffic through
the physical entity.  The feature accomplishes this by
characterizing roles for physical entities baed on their
configuration.
        
Following terminology is introduced with selective VRF
download feature:
        
Core Facing      A physical entity which has only core
                 facing interfaces (interfaces that
                 connect to other Provider/Provider Edge
                 devices).
        
Customer Facing  A line physical entity which has one or
                 more customer facing interfaces
                 (interfaces that connect to Customer
                 Edge devices in different VRFs).
        
Local prefix     A prefix that is received from a
                 Customer edge device connected to the
                 router in a configured VRF context.
        
Remote prefix    A prefix received from another Provider
                 Edge device and is imported to a
                 configured VRF.
        
See the following references for futher information:
        
RFC 3813 - Multiprotocol Label Switching (MPLS)
Label Switching Router (LSR) Management Information
base (MIB), C. Srinivasan, A. Vishwanathan, and
T. Nadeau, June 2004
        
RFC 4382 - MPLS/BGP Layer 3 Virtual Private Network
(VPN) Management Information Base, T. Nadeau &
van Der Linde, February 2006
        
Acronyms:
VRF Virtual Routing and Forwarding
VPN Virtual Private Network
P   Provider Core Device
PE  Provider Edge Device
CE  Customer Edge Device
AFI Address Family Identifier
CEF Cisco Express Forwarding