By interoperating with the MPLS VPN-Tagging Server, IP Availability Manager is able to correctly represent in its repository the overlapping IP configurations that are shown in IP overlapping configuration 1: separate PE-CE pairs, IP overlapping configuration 2: common PE, separate CEs, and IP overlapping configuration 3: common PE and CE, separate VRFs.
Note that the CE device in configuration 3 is a multi-VRF CE. A multi-VRF CE maintains VPN routing and forwarding (VRF) tables for the purpose of extending the privacy and security of an MPLS L3VPN from the PE to the branch office. The multi-VRF CE maintains a VRF table for each interface or subinterface, to provide each client organization with its own IP address space.