BGP and VRF configurations are already in place. An engineer must leak routes from the default VRF to TENANT_1 VRF and TENANT_2 VRF, but not between the nondefault VRFs. Which feature allows the engin

"VRF default map" is not a standard or recognized feature in networking for controlling route leaking between VRFs.

Route targets (RTs) are extended BGP communities used to control the import and export of VPN routes between different Virtual Routing and Forwarding (VRF) instances. By configuring specific export RTs on the default VRF and corresponding import RTs on TENANT_1 and TENANT_2 VRFs, routes can be leaked selectively. Furthermore, by ensuring TENANT_1 and TENANT_2 VRFs do not share common import/export RTs, routes are prevented from leaking directly between them.

BGP redistribution is typically used to exchange routes between different routing protocols or BGP processes, but for route leaking *between VRFs* within an MPLS VPN environment, route targets are the precise and standard mechanism.

Route distinguishers (RDs) are used to make identical IP prefixes unique within the VPNv4/VPNv6 address family, thereby allowing multiple VRFs to have overlapping IP addresses, but they do not control the import or export policy of routes between VRFs.