As already discussed in the introduction to this chapter, the IPv6-over-MPLS transport (6PE) uses concepts that are similar to the MPLS VPN architecture, as follows:
IPv6 routes are exchanged between the PE routers and the CE routers. Contrary to MPLS VPN architecture, these routes are entered into the global IPv6 routing table on the PE routers, whereas in the MPLS VPN architecture, the VPNv4 routes are entered in the virtual routing and forwarding instance (VRF) tables. (As of the publication of this book, Cisco IOS does not support IPv6 VPNs.)
Labels are assigned to local IPv6 routes as they are redistributed into IPv6 BGP.
IPv6 routes and associated labels are exchanged between PE routers in MP-BGP sessions ...