MPLS VPN overlapping IP discovery is based on the following assumptions and criteria:

  • The loopback IP address of each CE device is unique and known.

  • The loopback IP address of each CE device must be used to advertise the route in the VRF; that is, the CE device can be identified by its loopback IP address.

  • The Loopback IP address is not tagged by any IP tag filter that a user has created by using the IP tagging feature in IP Availability Manager.

  • Each VRF has a route distinguisher.

    IP objects of interfaces that are associated with a single VRF have the same 8-byte route distinguisher value. The purpose of the route distinguisher is to allow the creation of distinct routes to separate instances of the same (overlapping) IPv4 address.

  • VRF name is unique on each single device.

  • IP address is unique on each CE device. This assumption is not applicable to the overlapping IP configuration that is shown in GUID-C0AB0B46-A796-4D64-9852-675E874A9F17.html#GUID-C0AB0B46-A796-4D64-9852-675E874A9F17___MPLS_DISCO_OVERLAPPING_96293. For this reason, the overlapping IP discovery feature cannot be used to build interface-level network connections between the PE and CE for the configuration in Figure 19.