MPLS-VPNs, Internet Service Providers and IPv6
When you think about MPLS-VPN and the IPv4 or IPv6 Internet, there are two basic problems you want to solve, two important questions you need to answer.
1) How are you providing Internet Access to the MPLS-VPN customers?
2) What if your MPLS-VPN customers are Internet Service Providers who need your MPLS-VPN service to interconnect their remote sites (POP)?
Why do you have a case here? This is because MPLS-VPN, and later 6VPE which added IPv6 support in MPLS-VPN, were not designed to support the full Internet routing tables in the VPN Routing and Forwarding tables. The VRF were designed to connect private networks, not networks the size of the Internet. This is an obvious memory size and CPU resource requirements issue. How can you think a PE could manage multiple copies of the Internet Routing table (RIB) and their associated Forwarding bases (FIB)?
Let’s start with the first issue:
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