Juniper JUNOSE SOFTWARE FOR E SERIES 11.0.X - BGP AND MPLS CONFIGURATION GUIDE 2009-12-30 Configuration Manual page 424

JUNOSe 11.0.x BGP and MPLS Configuration Guide
CE 6 receives the IP packet from PE 2 and looks up the destination address Host 2.
Subsequent forwarding to Host 2 occurs by means of the IGP in the customer site.
The network structure shown in Figure 75 on page 387 consists of two VPNs, A and
B. VPN A comprises CE 1, CE 5, and CE 6. VPN B comprises CE 2, CE 3, and CE 4.
CE 1 has data traffic destined for both CE 5 and CE 6. Because both of these
destination sites are within the same VPN, PE 1 uses the same forwarding table, in
VRF A, to do the lookups and MPLS encapsulation. The innermost label determines
the destination VRF and is the same for all packets in that VPN, even if they are
destined for different CE routers. CE 2 and CE 3 have traffic destined for CE 4. Because
these all are in VPN B, PE 1 uses a different forwarding table, in VRF B, for looking
up destinations for traffic originating with these sites. However, both VPNs use the
same LSP, because both VPNs use the same ingress (PE 1) to and the same egress
(PE 2) from the service provider core. Remember that the illustrated LSP carries data
traffic only from PE 1 to PE 2. Traffic from PE 2 to PE 1 requires a different LSP.
Configuring IPv6 VPNs
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.
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.
address-family
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Configuring IPv6 VPNs