A route target identifies a set of customer VPN sites to which a PE device distributes routes. It is used to set up peering relationships between the VRF instances that belong to the same VPN.
Both multicast VPN and unicast VPN for a customer may be constructed by the same route target, or the multicast VPN may be constructed by a different route target for the same customer.
Route target is described in “RouteTarget (Layer 2)” on page 57. The description lists the key attributes for RouteTarget and identifies events that are detected for RouteTarget.
For a unicast L3VPN, the VPNType attribute for a RouteTarget is set to RFC_2547. For a multicast L3VPN, the VPNType attribute for a RouteTarget is set to BGP_IP_VPN.