Bgp Control Plane Behavior; Ce-Pe Behavior; Figure 76: Ipv6 Vpn Services Over Ipv4 Mpls - Juniper BGP - CONFIGURATION GUIDE V 11.1.X Configuration Manual

JUNOSe 11.1.x BGP and MPLS Configuration Guide

Figure 76: IPv6 VPN Services over IPv4 MPLS

The PE routers use an MP-BGP session over TCPv4 to advertise the IPv6 routes from
the CE devices to the remote PE routers. The IPv6 routes are advertised as labeled
VPNv6 routes with a BGP next hop set to the base tunnel endpoint destination address.
The next hop is formatted as an IPv4-mapped IPv6 address.
For IPv6 VPN services over an IPv4 backbone, the BGP next hop in the
MP_REACH_NLRI attribute contains a VPN-IPV6 address with the RD set to zero and
with the 16-byte IPv6 address encoded as an IPv4-mapped IPv6 address that contains
the IPv4 address of the advertising PE router. This IPv4 address must be routable in
the service provider's backbone.

BGP Control Plane Behavior

The VPN service in Figure 76 on page 396 includes both CE 1 (VRF A) and CE 2 (VRF
B). The MPLS base tunnels are established to tunnel endpoints PE 1 and PE 2 at their
loopback interfaces. The loopback address for PE 1 is FFFF::1.1.1.1/128; for PE 2, it
is FFFF::2.2.2.2/128.
The BGP next hop that is advertised in the MP-BGP update includes the following:
The IPv4 IGP, such as OSPF, advertises the reachability of the loopback interfaces
on the PE routers. LDP binds label L2 to 1.1.1.1/32 on the P router.
CE PE Behavior
CE 1 is connected to VRF A in PE 1 through an IPv4 interface. Similarly, CE 2 is
connected to VRF B in PE 2 through an IPv4 interface. You can alternatively run
OSPF to the CE devices over IPv6 links and redistribute the OSPF IPv6 routes into
BGP.
The MP-BGP sessions between the CE devices and the VRFs in the PE routers are
established over TCPv4. The AFI value is 2, indicating IPv6; the SAFI value is 1,
indicating unicast. CE 1 advertises IPv6 network 6001:0430::/48 to its MP-BGP peer
in VRF A. CE 2 advertises 6001:0431::/48 to its MP-BGP peer in VRF B. When it
receives the advertised prefix in VRF A, BGP adds 6001:0430::/48 to its BGP VPNv6
396
Intra-AS IPv6 VPNs
A VPN-IPV6 address with the RD set to zero
The 16-byte IPv6 address encoded as an IPv4-mapped IPv6 address that contains
the IPv4 loopback address of the advertising PE router