Cisco Cisco IOS Software Release 12.2(27)SBC

Border Gateway Protocol peering sessions are established. 

CEF or dCEF (for distributed platforms) is enabled on all participating routers.

Only IPv4 unicast and multicast prefixes can be imported to a VRF with this feature. 

A maximum of 5 VRF instances per router can be created to import IPv4 prefixes from the global 
routing table.

IPv4 prefixes imported into a VRF, using this feature, cannot be imported into a VPNv4 VRF. 

The BGP Support for IP Prefix Import from Global Table into a VRF Table feature introduces the 
capability to import IPv4 unicast prefixes from the global routing table into a Virtual Private Network 
(VPN) routing/forwarding instance (VRF) table using an import map. This feature extends the 
functionality of VRF import-map configuration to allow IPv4 prefixes to be imported into a VRF based 
on a standard community. Both IPv4 unicast and multicast prefixes are supported. No Multiprotocol 
Label Switching (MPLS) or route target (import/export) configuration is required. 

IP prefixes are defined as match criteria for the import map through standard Cisco IOS filtering 
mechanisms. For example, an IP access-list, an IP prefix-list, or an IP as-path filter is created to define 
an IP prefix or IP prefix range, and then the prefix or prefixes are processed through a match clause in a 
route map. Prefixes that pass through the route map are imported into the specified VRF per the import 
map configuration.