Cisco Cisco IOS Software Release 12.2(33)SRE

The MPLS VPN - Route Target Rewrite feature requires the following:

You should know how to configure Multiprotocol Virtual Private Networks (MPLS VPNs).

You need to configure your network to support interautonomous systems (Inter-autonomous system) 
with different route target (RT) values in each autonomous system.

You need to identify the RT replacement policy and target router for each autonomous system.

You can apply multiple replacement rules using the route-map continue clause. The MPLS VPN - Route 
Target Rewrite feature does not support the continue clause on outbound route maps.

To configure the MPLS VPN - Route Target Rewrite feature, you need to understand the following 
concepts:

Routing policies for a peer include all configurations that may impact inbound or outbound routing table 
updates. The MPLS VPN - Route Target Rewrite feature can influence routing table updates by allowing 
the replacement of route targets on inbound and outbound BGP updates. Route targets are carried as 
extended community attributes in BGP Virtual Private Network IP Version 4 (VPNv4) updates. Route 
target extended community attributes are used to identify a set of sites and VPN routing and forwarding 
(VRF) instances that can receive routes with a configured route target.