MPLS 6PE

Introduction

MPLS 6PE is one of the ways to provide IPv6 service over MPLS. 6PE does not support VPN type functionality and operates in the default routing table. As a comparison, MPLS 6VPE, is the other method where VPNs are supported.

MPLS 6PE

  • Based on RFC4659 - Connecting IPv6 Islands over IPv4 MPLS Using IPv6 Provider Edge Routers
  • Operates over MPLS IPv4 core network. Requires LDP for IPv4 addressing. Currently no IPv6 Label Distribution Protocol integration.
  • Relies on the BGP protocol to advertise IPv6 prefix label.
  • Why do you have to send a label using MP-BGP if no VPNs exist? The first label is the transport label for IPv4 PE loopback, while the second is generated for the IPv6 prefix.
  • Does not tunnel in IPv4 packets, but only relies on the IPv4 address to switch the correct path using labels towards those PE's IPv4 addresses.
  • MPLS 6PE uses the default routing table and does not work with VRFs.
  • Feature configured under the MP-BGP address-family ipv6.
  • Customers have to be using global IPv6 addresses to eliminate possible collision with other customers' networks.
  • All routes will be redistribute, instead of reassembled as with regular MPLS VPN. When they are redistributed, the route type is external.
  • The Next-Hop for IPv6 prefixes is the IPv4 PE Loopback address encoded within IPv4-Mapped IPv6 Address (RFC4291). It is formatted to include the IPv4 address within a special IPv6 address. For example, the PE Loopback IPv4 address 150.1.1.1 would be encoded into:

::FFFF:150.1.1.1

MPLS 6PE Internet Access

Comments

rating: 0+x
Unless otherwise stated, the content of this page is licensed under Creative Commons Attribution-ShareAlike 3.0 License