MPLS VPN extranet route leaking unique addressing
When configuring an MPLS Extranet VPN, connectivity is established between multiple parties using route leaking from one VRF to another. When this is done, the addresses that are leaked must be unique and not overlap with the IP address space of the existing VRF.
In the event that there is overlap, NAT can be used to maintain their uniqueness.
Links:
https://networklessons.com/cisco/ccie-routing-switching-written/mpls-vpn-extranet-route-leaking/