Subject: I-D Action: draft-mishra-bess-ipv4nlri-ipv6nh-use-cases-00.txt

From: [email-masked]
Date: Mon, 27 Apr 2020 15:35:46 -0700

A New Internet-Draft is available from the on-line Internet-Drafts directories.

        Title           : IPv4 Network Layer Reachability Information with IPv6 Next Hop Use Cases
        Author          : Gyan S. Mishra
	Filename        : draft-mishra-bess-ipv4nlri-ipv6nh-use-cases-00.txt
	Pages           : 15
	Date            : 2020-04-27

Abstract:
   As Enterprises and Service Providers upgrade their brown field or
   green field core to an IPv6 transport such as an MPLS LDPv6 core or
   SRv6 core, Multiprotocol BGP (MP-BGP)now plays an important role in
   the transition of the core from IPv4 to IPv6 being able to continue
   to support legacy IPv4, VPN-IPv4, and Multicast VPN customers.  IXPs
   (Internet Exchange points) are also facing IPv4 address depletion at
   their peering points, which are large Layer 2 transit backbones that
   service providers peer and exchange IPv4 and IPv6 (Network Layer
   Reachability Information) NLRI.  Today these transit exchange points
   are dual stacked.  One proposal to solve this issue is to use
   [RFC5549] to carry IPv4 (Network Layer Reachability Information) NLRI
   in an IPv6 next hop and eliminate the IPv4 peering completely using
   the concept of [RFC5565] softwire mesh framework.  So now with the
   MP-BGP reach capability exchanged over IPv4 AFI over IPv6 next hop
   peer we can now advertise IPv4(Network Layer Reachability
   Information) NLRI over IPv6 peering using the [RFC5565] softwire mesh
   framework.  Multiprotocol BGP (MP-BGP) specifies that the set of
   usable next-hop address families is determined by the Address Family
   Identifier (AFI) and the Subsequent Address Family Identifier (SAFI).
   Historically the AFI/SAFI definitions for the IPv4 address family
   only have provisions for advertising a Next Hop address that belongs
   to the IPv4 protocol when advertising IPv4 or VPN-IPv4 Network Layer
   Reachability Information (NLRI).  [RFC5549] specifies the extensions
   necessary to allow advertising IPv4 NLRI or VPN-IPv4 NLRI with a Next
   Hop address that belongs to the IPv6 protocol.  This comprises an
   extension of the AFI/SAFI definitions to allow the address of the
   Next Hop for IPv4 NLRI or VPN-IPv4 NLRI to also belong to the IPv6
   Protocol.  [RFC5549] defines the encoding of the Next Hop to
   determine which of the protocols the address actually belongs to, and
   a new BGP Capability allowing MP-BGP Peers to dynamically discover
   whether they can exchange IPv4 NLRI and VPN-IPv4 NLRI with an IPv6
   Next Hop.  With this new MP-BGP capability exchange allows the BGP
   peering session to act as a pure transport to allow the session to
   carry Address Family Identifier (AFI) and the Subsequent Address
   Family Identifier (SAFI) for both IPv4 and IPv6.  This document
   describes the critical use case and OPEX savings of being able to
   leverage the MP-BGP capability exchange usage as a pure transport
   allowing both IPv4 and IPv6 to be carried over the same BGP TCP
   session.  By doing so allows for the elimination of Dual Stacking on
   the PE-CE connections making the peering IPv6 only carrying both IPv4
   and IPv6 Network Layer Reachability Information (NLRI).  This
   document also provides a possible solution for IXPs (Internet
   Exchange points) that are facing IPv4 address depletion at these
   peering points to use BGP-MP capability exchange defined in [RFC5549]
   to carry IPv4 (Network Layer Reachability Information) NLRI in an
   IPv6 next hop using the [RFC5565] softwire mesh framework.

The IETF datatracker status page for this draft is:
https://datatracker.ietf.org/doc/draft-mishra-bess-ipv4nlri-ipv6nh-use-cases/

There are also htmlized versions available at:
https://tools.ietf.org/html/draft-mishra-bess-ipv4nlri-ipv6nh-use-cases-00
https://datatracker.ietf.org/doc/html/draft-mishra-bess-ipv4nlri-ipv6nh-use-cases-00

Please note that it may take a couple of minutes from the time of submission
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