7. Carriers' Carriers

Sometimes, an IPv6 VPN may actually be the network of an IPv6 ISP, with its own peering and routing policies. Sometimes, an IPv6 VPN may be the network of an SP that is offering VPN services in turn to its own customers. IPv6 VPNs like these can also obtain backbone service from another SP, the "Carrier's Carrier", using the Carriers' Carrier method described in Section 9 of [BGP/MPLS-VPN] but applied to IPv6 traffic. All the considerations discussed in [BGP/MPLS-VPN] for IPv4 VPN Carriers' Carrier apply for IPv6 VPN, with the exception that the use of MPLS (including label distribution) between the PE and the CE pertains to IPv6 routes instead of IPv4 routes.