How does MPLS Layer 3 VPN function?

When a VPN route is learned from a CE device and injected into IGP, a VPN route distinguisher attribute is associated with it.

When a destination PE device receives a labeled packet, it pops the label and uses it to forward the packet to the correct CE device.

When an EIGRP internal route is redistributed into BGP by one PE and then back into EIGRP by another PE, the originating router ID for the route is changed to the router ID of the first PE

When a PE device forwards a packet received from a CE device across the provider network, it labels the packet with the label learned from the source PE device.