Proxy BGP route target filtering

This feature (also known as proxy route target constrain, or proxy RTC) permits the generation of route target membership (RT membership) for devices that do not support route target filtering. This eases the deployment of route target filtering in networks where it is incompletely deployed or not fully supported. Proxy BGP route target filtering allows you to distribute proxy RT membership advertisements created from the received BGP VPN routes to other devices in the network that need them. These are known as proxy advertisements because the device creates the RT membership on behalf of its peers without the route target filtering functionality. Proxy BGP route target filtering uses BGP route target extended communities that are exported to a specific BGP speaker to generate the route targets.