# IPv6 VPN Overview

The JunosE Software supports IPv6 VPNs tunneled over an MPLS IPv4 backbone. A service provider can offer IPv4 VPN services, IPv6 VPN services, or both. MPLS over IPv6 is not currently supported. MPLS base tunnels to IPv6 destinations as tunnel endpoints are not supported, so you cannot establish an MPLS IPv6 backbone.

| Note: You must configure an IPv6 interface in the parent VR for IPv6 VPNS to work.

BGP can negotiate VPNv6 capability without having to negotiate the IPv6 capability. BGP next-hop encoding varies depending on whether the backbone is IPv4 or IPv6. In the JunosE Software implementation for IPv6 VPNs, the BGP next hops in the MP-BGP update message follow the convention for BGP next-hop encoding for IPv4 backbone. If an E Series router receives a BGP next hop that follows the encoding for an MPLS-enabled IPv6 backbone, that BGP next hop is treated as unreachable because currently no MPLS base tunnel to the native IPv6 tunnel endpoint address can exist.

The PE routers have both IPv4 and IPv6 capabilities. They maintain IPv6 VRFs for their IPv6 sites and encapsulate IPv6 traffic in MPLS frames that are then sent into the MPLS core network.

Link-local scope addresses cannot be used for reachability across IPv6 VPN sites and can never be advertised by means of MP-BGP to remote PE routers. Global scope addresses are expected to be used within and across IPv6 VPN Sites.

Creating an address family for a VRF automatically disables both synchronization and automatic summarization for that VRF.

All features previously supported for BGP/MPLS IPv4 VPNs, such as policy-based routing, redistribution to and from other protocols, aggregation, route-flap dampening, and so on are also supported for BGP/MPLS IPv6 VPNs.