Juniper JUNOSE 11.2.X BGP AND MPLS, Руководство по настройке

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Carrier-of-Carriers Using BGP as the Label Distribution Protocol
You can run BGP instead of LDP as the label distribution protocol on the PE-CE link
between the Tier 1 and the Tier 2 carriers in a carrier-of-carriers topology. This capability
is available for carriers providing Internet access or VPN service to end users.
Carrier-of-Carriers IPv6 VPNs
Figure 109 on page 475 illustrates a carrier-of-carrier scenario with IPv6 VPNs. MPLS labels
are exchanged on the PE–CE link for customer-internal routes, but customer-external
routes are not imported either into the VRFs on the PE router or into the core. VRFs
maintain a routing table only for the customer-internal routes. Forwarding is accomplished
primarily by label switching, without a routing table lookup.
Only customer-external routes (Tier 2 ISP routes as shown in Figure 109 on page 475) can
be native IPv6 addresses. Because LDP over TCP over IPv6 is not currently supported,
the customer-internal routes for which LDP can give out labels (Tier 1 ISP routes in Figure
109 on page 475) must be IPv4 addresses; they cannot be IPv6 addresses, whether native
or IPv4-mapped.
For more information about carrier-of-carriers VPNs, see “Carrier-of-Carriers IPv4 VPNs”
on page 469
.
Figure 109: Carrier-of-Carrier IPv6 VPNs
475 Copyright © 2010, Juniper Networks, Inc.
Chapter 6: Configuring BGP-MPLS Applications