IPv4-Only PE Design All SAFI
draft-mishra-bess-ipv4-only-pe-design-all-safi-01
The information below is for an old version of the document.
| Document | Type |
This is an older version of an Internet-Draft whose latest revision state is "Replaced".
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|---|---|---|---|
| Authors | Gyan Mishra , Jeff Tantsura , Mankamana Prasad Mishra , Sudha Madhavi , Qing Yang , Adam Simpson , Shuanglong Chen | ||
| Last updated | 2022-07-07 | ||
| Replaced by | draft-ietf-bess-v4-v6-pe-all-safi | ||
| RFC stream | (None) | ||
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| Consensus boilerplate | Unknown | ||
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draft-mishra-bess-ipv4-only-pe-design-all-safi-01
BESS Working Group G. Mishra
Internet-Draft Verizon Inc.
Intended status: Standards Track J. Tantsura
Expires: 8 January 2023 Microsoft, Inc.
M. Mishra
Cisco Systems
S. Madhavi
Juniper Networks, Inc.
Q. Yang
Arista Networks
A. Simpson
Nokia
S. Chen
Huawei Technologies
7 July 2022
IPv4-Only PE Design All SAFI
draft-mishra-bess-ipv4-only-pe-design-all-safi-01
Abstract
As Enterprises and Service Providers try to decide whether or not to
upgrade their brown field or green field MPLS/SR core to an IPv6
transport, Multiprotocol BGP (MP-BGP)now plays an important role in
the transition of their Provider (P) core network as well as Provider
Edge (PE) Edge network from IPv4 to IPv6. Operators must be able to
continue to support IPv4 customers when both the Core and Edge
networks are IPv4-Only.
[I-D.mishra-bess-ipv4-only-pe-design] details an important External
BGP (eBGP) PE-CE Edge IPv4-Only peering design that leverages the MP-
BGP capability exchange by using IPv4 peering as pure transport,
allowing both IPv4 Network Layer Reachability Information (NLRI) and
IPv6 Network Layer Reachability Information (NLRI)to be carried over
the same (Border Gateway Protocol) BGP TCP session. The design
change provides the same Dual Stacking functionality that exists
today with separate IPv4 and IPv6 BGP sessions as we have today.
With this design change from a control plane perspective a single
IPv4 is required for both IPv4 and IPv6 routing updates and from a
data plane forwarindg perspective an IPv4 address need only be
configured on the PE and CE interface for both IPv4 and IPv6 packet
forwarding.
[I-D.mishra-bess-ipv4-only-pe-design] provides a IPv4-Only PE design
solution for use cases where operators are not yet ready to migrate
to IPv6 or SRv6 core and would like to stay on IPv4-Only Core short
to long term and maybe even indefinitely. With this design,
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operators can now remain with an IPv4-Only Core and do not have to
migrate to an IPv6-Only Core. From a technical standpoint the
underlay can remain IPv4 and still transport IPv6 NLRI to support
IPv6 customers, and so does not need to be migrated to IPv6-Only
underlay. With this IPv4-Only PE Design solution , IPv4 addressing
only needs to be provisioned for the IPv4-Only PE-CE eBGP Edge
peering design, thereby eliminating IPv6 provisioning at the Edge.
This core and edge IPv4-Only peering design can apply to any eBGP
peering, public internet or private, which can be either Core
networks, Data Center networks, Access networks or can be any eBGP
peering scenario.
This document details an important External BGP (eBGP) PE-PE Inter-AS
IPv6-Only peering design that leverages the MP-BGP capability
exchange by using IPv6 peering as pure transport, allowing all and
any IPv4 Network Layer Reachability Information (NLRI) and IPv6
Network Layer Reachability Information (NLRI)to be carried over the
same (Border Gateway Protocol) BGP TCP session for all Address Family
Identifiers (AFI) and Subsequent Address Family Identifiers(SAFI).
The design change provides the same Dual Stacking functionality that
exists today with separate IPv4 and IPv6 BGP sessions as we have
today. With this IPv4-Only PE Design, IPv6 address MUST not be
configured on the the Provider Edge (PE) - Customer Edge (CE), or
Inter-AS ASBR (Autonomous System Boundary Router) to ASBR (Autonomous
System Boundary Router) PE-PE Provider Edge (PE) - Provider Edge
(PE). From a control plane perspective a single IPv4-Only peer is
required for both IPv4 and IPv6 routing updates and from a data plane
forwarindg perspective an IPv4 address need only be configured on the
PE to PE Inter-AS peering interface for both IPv4 and IPv6 packet
forwarding. This document defines the IPv4-Only PE Design as a new
PE-CE Edge and ASBR-ASBR PE-PE Inter-AS BGP peering Standard which is
described in the POC testing document
[I-D.mishra-bess-ipv4-only-pe-design] which is now extended to
support to all AFI/SAFI ubiquitously. As service providers migrate
to Segment Routing architecture SR-MPLS and SRv6, VPN overlay exsits
as well, and thus Inter-AS options Option-A, Option-B, Option-AB and
Option-C are still applicable and thus this extension of IPv4-Only
peering architecure extension to Inter-AS peering is very relevant to
Segment Routing as well.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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Internet-Drafts are working documents of the Internet Engineering
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This Internet-Draft will expire on 8 January 2023.
Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
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provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 7
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 7
4. IPv4-Only PE-CE Design ALL SAFI Solution . . . . . . . . . . 8
4.1. IPv4-Only Edge Peering Design . . . . . . . . . . . . . . 9
4.1.1. IPv4-Only PE Design ALL SAFI 6to4 Softwire IPv4-Only
Core packet walk . . . . . . . . . . . . . . . . . . 9
4.1.2. IPv4-Only PE Design ALL SAFI 6to4 Softwire - IPv6 Edge
over an IPv4-Only Core . . . . . . . . . . . . . . . 9
4.1.3. IPv4-Only PE Design ALL SAFI 4to6 Softwire - IPv4 Edge
over an IPv6-Only Core . . . . . . . . . . . . . . . 11
5. RFC5549 and RFC8950 Applicability to IPv4-Only PE Design . . 13
5.1. IPv4-Only Edge Peering design next-hop encoding . . . . . 14
5.2. IPv4-Only PE Design Next Hop Encoding . . . . . . . . . . 14
6. IPv4-Only PE Design Edge E2E Design for ALL AFI/SAFI . . . . 16
6.1. IPv4-Only PE Design All SAFI Case-1 E2E IPv4-Only PE-CE,
Global Table over IPv4-Only Core(6PE), 6to4 softwire . . 16
6.2. IPv4-Only PE Design All SAFI Case-2 E2E IPv4-Only PE-CE,
VPN over IPv4-Only Core, 6to4 Softwire . . . . . . . . . 16
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6.3. IPv4-Only PE Design All SAFI Case-3 E2E IPv4-Only PE-CE,
Global Table over IPv6-Only Core (4PE), 4to6 Softwire . 17
6.4. IPv4-Only PE Design All SAFI Case-4 E2E IPv4-Only PE-CE,
VPN over IPv6-Only Core, 4to6 Softwire . . . . . . . . . 17
6.5. IPv4-Only PE Design All SAFI Case-5 E2E IPv4-Only PE-CE,
Global Table over IPv4-Only Core(6PE), 6to4 softwire
-Inter-AS Option-B . . . . . . . . . . . . . . . . . . . 18
6.6. IPv4-Only PE Design All SAFI Case-6 E2E IPv4-Only PE-CE,
Global Table over IPv4-Only Core(6PE), 6to4 softwire
-Inter-AS Option-C . . . . . . . . . . . . . . . . . . . 18
6.7. IPv4-Only PE Design All SAFI Case-7 E2E IPv4-Only PE-CE,
VPN over IPv4-Only, 6to4 softwire -Inter-AS Option-B . . 19
6.8. IPv4-Only PE Design All SAFI Case-8 E2E IPv4-Only PE-CE,
VPN over IPv4-Only Core, 6to4 softwire -Inter-AS
Option-C . . . . . . . . . . . . . . . . . . . . . . . . 19
6.9. IPv4-Only PE Design All SAFI Case-9 E2E IPv4-Only PE-CE,
Global Table over IPv6-Only Core, 4to6 softwire -Inter-AS
Option-B . . . . . . . . . . . . . . . . . . . . . . . . 20
6.10. IPv4-Only PE Design All SAFI Case-10 E2E IPv4-Only PE-CE,
Global Table over IPv6-Only Core, 4to6 softwire -Inter-AS
Option-C . . . . . . . . . . . . . . . . . . . . . . . . 20
6.11. IPv4-Only PE Design All SAFI Case-11 E2E IPv4-Only PE-CE,
VPN over IPv6-Only Core, 4to6 softwire -Inter-AS
Option-B . . . . . . . . . . . . . . . . . . . . . . . . 21
6.12. IPv4-Only PE Design All SAFI Case-12 E2E IPv4-Only PE-CE,
VPN over IPv6-Only Core, 4to6 softwire -Inter-AS
Option-C . . . . . . . . . . . . . . . . . . . . . . . . 21
7. IPv6-Only PE Design ALL AFI/SFI Operational Considerations . 22
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23
9. Security Considerations . . . . . . . . . . . . . . . . . . . 23
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 23
11. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 23
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 23
12.1. Normative References . . . . . . . . . . . . . . . . . . 24
12.2. Informative References . . . . . . . . . . . . . . . . . 26
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 27
1. Introduction
As Enterprises and Service Providers upgrade their brown field or
green field MPLS/SR core to an IPv6 transport such as MPLS LDPv6, SR-
MPLSv6 or SRv6, Multiprotocol BGP (MP-BGP) now plays an important
role in the transition of the Provider (P) core networks and Provider
Edge (PE) edge networks from IPv4 to IPv6. Operators have a
requirement to support IPv6 customers and must be able to support
IPv6 address family and Sub-Address-Family Virtual Private Network
(VPN)-IPv6, and Multicast VPN IPv6 customers.
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With this IPv4-only BGP peering design, only IPv4 is configured on
the PE-CE interface, the Provider Edge (PE) - Customer Edge (CE), the
IPv4 BGP peer is now used to carry IPv6 (Network Layer Reachability
Information) NLRI over an IPv4 next hop using 4 byte IPv4 next hop
encoding while continuing to forward both IPv4 and IPv6 packets. In
the framework of this design the PE is no longer Dual Stacked.
However in the case of the CE, PE-CE link CE side of the link is no
longer Dual Stacked, however all other internal links within the CE
domain may or maynot be Dual stacked.
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. [RFC8950] specifies the extensions
necessary to allow advertising IPv4 NLRI, Virtual Private Network
Unicast (VPN-IPv4) NLRI, Multicast Virtual Private Network (MVPN-
IPv4) NLRI with a Next Hop address that belongs to the IPv6 protocol.
This comprises of an extended next hop encoding MP-REACH BGP
capability exchange to allow the address of the Next Hop for IPv4
NLRI, VPN-IPv4 NLRI and MVPN-IPv4 NLRI to also belong to the IPv6
Protocol. [RFC8950] 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 discover dynamically
whether they can exchange IPv4 NLRI and VPN-IPv4 NLRI with an IPv6
Next Hop.
With the IPv4-Only PE design, IPv6 NLRI will be carried over an IPv4
Next-hop. [RFC4798] and [RFC4659] specify how an IPv4 address can be
encoded inside the next-hop IPv6 address field when IPv6 NLRI needs
to be advertised with an IPv4 next hop. [RFC4798] defines how the
IPv4-mapped IPv6 address format specified in the IPv6 addressing
architecture [RFC4798] can be used for that purpose when the <AFI/
SAFI> is IPv6-Unicast <2/1>, Multicast <2/2>, and Labeled Unicast
<2/4>. [RFC4659] defines how the IPv4-mapped IPv6 address format as
well as a null Route Distinguisher as ::FFFF:192.168.1.1 (RD) can be
used for that purpose when the <AFI/SAFI> is VPN-IPv6 <2/128> MVPN-
IPv6 <2/129>. This IPv4-Only PE specification utilizes IPv6 NLRI
over IPv4 Next hop encoding adopted by the industy to not use IPv4
mapped IPv6 address defined above, and instead use 4 byte IPv4
address for the next hop which ultimately set the precedence for the
adoption of [RFC8950] for 4to6 Softwire IPv4 NLRI over IPv6 next-hop
using an IPv6 address for the next hop and not a IPv6 mapped IPv4
address. The IPv4 next hop encoding for cases where the NLRI
advertised is different from the next hop encoding such as where IPv6
NLRI is advertied with IPv4 next hop for for <AFI/SAFI> is
IPv6-Unicast <2/1>, Multicast <2/2>, and Labeled Unicast <2/4>.
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[RFC4659] defines Null(RD) for <AFI/SAFI> is VPN-IPv6 <2/128> MVPN-
IPv6 <2/129> but now with a an official new IANA Capability code TBD
as value 10 "IPv4 Next Hop Encoding". The IETF standards have not
been updated with an IANA allocation Capability code for the IPv4
next hop encoding so this specification fixes that problem with an
IANA allocated capability codepoint which will now be used for any
eBGP or iBGP peering as well as the IPv4-Only PE design defined in
this specification.
With this IPv4-Only PE Design, BGP peer session can now be treated as
a pure TCP transport and carry both IPv4 and IPv6 NLRI at the
Provider Edge (PE) - Customer Edge (CE) over a single IPv4 TCP
session. This allows for the elimination of dual stack from the PE-
CE peering point, and now enable the peering to be IPv4-ONLY. The
elimination of IPv6 on the PE-CE peering points translates into OPEX
expenditure savings of point-to-point infrastructure links as well as
/127 address space savings and administration and network management
of both IPv4 and IPv6 BGP peers. This reduction decreases the number
of PE-CE BGP peers by fifty percent, which is a tremendous cost
savings for operators. This also translates into Major CAPEX savings
as now operators do not have to migrate their underlay to IPv6 and
can remain indefinitely on IPv4-Only Core.
This document defines the IPv4-Only PE Design Architecture details
for External BGP (eBGP) PE-PE Inter-AS IPv6-Only peering design that
leverages the MP-BGP capability exchange by using IPv6 peering as
pure transport, allowing all and any IPv4 Network Layer Reachability
Information (NLRI) and IPv6 Network Layer Reachability Information
(NLRI)to be carried over the same (Border Gateway Protocol) BGP TCP
session for all Address Family Identifiers (AFI) and Subsequent
Address Family Identifiers(SAFI). The design change provides the
same Dual Stacking functionality that exists today with separate IPv4
and IPv6 BGP sessions as we have today. With this IPv6-Only PE
Design, IPv6 address MUST not be configured on the the Provider Edge
(PE) - Customer Edge (CE), or Inter-AS ASBR (Autonomous System
Boundary Router) to ASBR (Autonomous System Boundary Router) PE-PE
Provider Edge (PE) - Provider Edge (PE). From a control plane
perspective a single IPv4-Only peer MUST be configured for both IPv4
and IPv6 routing updates, and from a data plane forwarindg
perspective only an IPv4 address MUST be configured on the PE-CE Edge
or ASBR-ASBR, PE to PE Inter-AS peering interface for both IPv4 and
IPv6 packet forwarding for all AFI/SAFI. This document defines the
IPv4-Only PE Design as a new Intra-AS PE-CE Edge and Inter-AS PE-PE
BGP peering Standard which is described in the POC testing document
in detail, [I-D.mishra-bess-ipv4-only-pe-design] which is now
extended for applicability to to all AFI/SAFI ubiquitously. As
service providers migrate to Segment Routing architecture SR-MPLS and
SRv6, VPN overlay exsits as well, and thus Inter-AS options Option-A,
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Option-AB and Option-C are still applicable and thus this extension
of IPv4-Only peering architecure extension to Inter-AS peering is
very relevant to Segment Routing as well as well as any other
applicable AFI/SAFI is now as well relevant.
This IPv4-Only PE ALL SAFI Design details an important External BGP
(eBGP) PE-PE Inter-AS IPv4-Only peering design that leverages the MP-
BGP capability exchange by using IPv6 peering as pure transport,
allowing all and any IPv4 Network Layer Reachability Information
(NLRI) and IPv6 Network Layer Reachability Information (NLRI) to be
carried over the same (Border Gateway Protocol) BGP TCP session for
all remaining Address Family Identifiers (AFI) and Subsequent Address
Family Identifiers(SAFI) below as well that can be carried over
IPv4-Only Inter-AS peerings: <AFI/SAFI> MCAST-VPN [RFC6514] <1/5>,
NLRI Multi-Segment Pseudowires [RFC7267] <1/6>, BGP Tunnel
Encapsulation SAFI [RFC9012] <1/7>, MCAST-VPLS [RFC7117] <1/8>, BGP
SFC [RFC9015] <1/9>, Tunnel SAFI [I-D.nalawade-kapoor-tunnel-safi]
<1/6>, Virtual Private LAN Service (VPLS) [RFC4761] and [RFC6074]
<1/5>, BGP MDT SAFI [RFC6037] <1/66>, BGP 4to6 SAFI [RFC5747] <1/67>,
BGP 6to4 SAFI draft xx <1/8>, Layer 1 VPN Auto-Discovery [RFC5195]
<1/69>, BGP EVPNs [RFC7432] <1/70>, BGP-LS (VPLS) [RFC7752] <1/71>,
BGP-LS-EVPN [RFC7752] <72/>, SR-TE Policy SAFI draftxx <1/73>, BGP
6to4 SAFI draft xx <1/8>, SDN WAN Capabilities draftxx <1/74>,
Routing Policy SAFI draftxx <1/75>, Classful-Transport SAFI draftxx
<1/76>, Tunneled Traffic FlowSpec draftxx <1/77>, MCAST-TREE SAFI
draft xx <1/78>, Route Target Constraints [RFC4684] <1/132>,
Dissemination of Flow Specification Rules [RFC8955] <1/133>, L3 VPN
Dissemination of Flow Specification Rules [RFC8955] <1/1344>, VPN
Auto-Discovery SAFI draftxx <1/140>
2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
3. Terminology
Terminolgoy used in defining the IPv6-Only Edge specification.
AFBR: Address Family Border Router Provider Edge (PE).
Edge: PE-CE Edge Network Provider Edge - Customer Edge
Core: P Core Network Provider (P)
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4to6 Softwire : IPv4 edge over an IPv6-Only core
6to4 Softwire: IPv6 edge over an IPv4-Only core
E2E: End to End
4. IPv4-Only PE-CE Design ALL SAFI Solution
The IPv4-Only Edge design solution applies to any and all IPv4
Network Layer Reachability Information (NLRI) and IPv6 Network Layer
Reachability Information (NLRI) over an IPv4-Only BGP Peering
session.
IPv4-Only PE Design ALL SAFI can be broken up into the following
design scenario's below:
Edge Customer NLRI IPv4 or IPV6 related AFI/SAFI (PE-CE): 1/1 2/1
(Unicast), 1/2 2/2 (Multicast)
Inter-AS Customer NLRI IPv4 or IPV6 related AFI/SAFI (ASBR-ASBR): 1/1
2/1 (Unicast), 1/2 2/2 (Multicast), 1/128 2/128 (VPN), 1/129 2/129
(MVPN), 1/4 2/4 BGP-LU (6PE/4PE), 1/140 2/140 (BGP VPN Auto
Discovery)
Inter-AS Multicast NLRI IPv4 or IPV6 related AFI/SAFI (ASBR-ASBR):
1/5 2/5 (MCAST-VPN) , 1/8 2/8 (MCAST-VPLS), 1/66 2/66 (BGP MDT-SAFI),
1/78 2/78 (MCAST-TREE)
PE to Controller NLRI IPv4 or IPV6 related AFI/SAFI 1/71 2/71 (BGP-
LS), 1/72 2/72 (BGP-LS VPN), 1/75 2/75 (Routing Policy SAFI), 1/80
2/80 BGP-LS-SPF
Inter-AS L1 VPN, L2 VPN NLRI IPv4 or IPV6 related AFI/SAFI (ASBR-
ASBR) 1/65 2/65 (VPLS), 1/70 2/70 (BGP EVPN), 1/69 2/69 (L1 VPN)
Inter-AS BGP FlowSpec, Optimizations and SFC NLRI IPv4 or IPV6
related AFI/SAFI (ASBR-ASBR) 1/132 2/132 (RTC), 1/133 2/133 (BGP
FlowSpec), 1/134 2/134 (VPN BGP FlowSpec), 1/9 2/9 (BGP SFC)
Inter-AS BGP Policy - SR-TE Policy, SD-WAN Policy NLRI IPv4 or IPV6
related AFI/SAFI (ASBR-ASBR) 1/73 2/73 (SR-TE), 1/74 2/74 (SD-WAN
Capabilities)
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Solution applicable to all AFI/SAFI
AFI/SAFI 1/X 2/X Where X = ALL SAFI
+-------+ +-------+
| AS1 | IPv6 Only | AS2 |
| PE1 |----------------| PE2 |
| (ASBR)| IPv6 BGP Peer |(ASBR) |
+-------+ +-------+
IPv4 forwarding IPv4 forwarding
IPv6 forwarding IPv6 forwarding
Figure 1: IPv4-Only Solution Applicability to ALL AFI/SAFI
4.1. IPv4-Only Edge Peering Design
4.1.1. IPv4-Only PE Design ALL SAFI 6to4 Softwire IPv4-Only Core packet
walk
The IPv4-Only Edge Peering design utilizes two key E2E Softwire Mesh
Framework scenario's, 4to6 softwire and 6to4 softwire. The Softwire
mesh framework concept is based on the overlay and underlay MPLS or
SR based technology framework, where the underlay is the transport
layer and the overlay is a Virtual Private Network (VPN) layer, and
is the the tunneled virtualization layer containing the customer
payload. The concept of a 6to4 Softwire is based on transmission of
IPv6 packets at the edge of the network by tunneling the IPv6 packets
over an IPv4-Only Core. The concept of a 4to6 Softwire is also based
on transmission of IPv4 packets at the edge of the network by
tunneling the IPv4 packets over an IPv6-Only Core.
This document describes End to End (E2E) test scenarios that follow a
packet flow from IPv4-Only attachment circuit from ingress PE-CE to
egress PE-CE tracing the routing protocol control plane and data
plane forwarding of IPv4 packets in a 4to6 softwire or 6to4 softwire
within the IPv4-Only or IPv6-Only Core network. In both secneario we
are focusing on IPv4 packets and the control plane and data plane
forwarding aspects of IPv4 packets from the PE-CE Edge network over
an IPv4-Only P (Provider) core network or IPv6-Only P (Provider) core
network. With this IPv4-Only Edge peering design, the Softwire Mesh
Framework is not extended beyond the Provider Edge (PE) and continues
to terminate on the PE router.
4.1.2. IPv4-Only PE Design ALL SAFI 6to4 Softwire - IPv6 Edge over an
IPv4-Only Core
6to4 softwire where IPv4-Edge eBGP IPv4 peering where IPv6 packets at
network Edge traverse a IPv4-Only Core
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In the scenario where IPv6 packets originating from a PE-CE edge are
tunneled over an MPLS or Segment Routing IPv4 underlay core network,
the PE and CE only have an IPv6 address configured on the interface.
In this scenario the IPv6 packets that ingress the CE from within the
CE AS are over an IPv4-Only interface and are forwarded to an IPv6
NLRI destination prefix learned from the Pure Transport Single IPv4
BGP Peer. In the IPv4-Only Edge peering architecture the PE is
IPv4-Only as all PE-CE interfaces are IPv4-Only. However, on the CE,
the PE-CE interface is the only interface that is IPv4-Only and all
other interfaces may or may not be IPv4-Only. Following the data
plane packet flow, IPv4 packets are forwarded from the ingress CE to
the IPv4-Only ingress PE where the VPN label imposition push per
prefix, per-vrf, per-CE occurs and the labeled packet is forwarded
over a 6to4 softwire IPv4-Only core, to the egress PE where the VPN
label disposition pop occurs and the native IPv4 packet is forwarded
to the egress CE. In the reverse direction IPv4 packets are
forwarded from the egress CE to egress PE where the VPN label
imposition per prefix, per-vrf, per-CE push occurs and the labeled
packet is forwarded back over the 6to4 softwire IPv4-Only core, to
the ingress PE where the VPN label disposition pop occurs and the
native IPv4 packet is forwarded to the ingress CE. . The
functionality of the IPv4 forwarding plane in this scenario is
identical from a data plane forwarding perspective to Dual Stack IPv4
forwarding scenario.
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+--------+ +--------+
| IPv4 | | IPv4 |
| Client | | Client |
| Network| | Network|
+--------+ +--------+
| \ / |
| \ / |
| \ / |
| X |
| / \ |
| / \ |
| / \ |
+--------+ +--------+
| AFBR | | AFBR |
+--| IPv4/6 |---| IPv4/6 |--+
| +--------+ +--------+ |
+--------+ | | +--------+
| IPv4 | | | | IPv4 |
| Client | | | | Client |
| Network|------| IPv4 |-------| Network|
+--------+ | only | +--------+
| |
| +--------+ +--------+ |
+--| AFBR |---| AFBR |--+
| IPv4/6 | | IPv4/6 |
+--------+ +--------+
| \ / |
| \ / |
| \ / |
| X |
| / \ |
| / \ |
| / \ |
+--------+ +--------+
| IPv6 | | IPv4 |
| Client | | Client |
| Network| | Network|
+--------+ +--------+
Figure 2: 6to4 Softwire - IPv6 Edge over an IPv4-Only Core
4.1.3. IPv4-Only PE Design ALL SAFI 4to6 Softwire - IPv4 Edge over an
IPv6-Only Core
4to6 softwire where IPv4-Edge eBGP IPv4 peering where IPv6 packets at
network Edge traverse a IPv6-Only Core
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In the scenario where IPv6 packets originating from a PE-CE edge are
tunneled over an MPLS or Segment Routing IPv4 underlay core network,
the PE and CE only have an IPv4 address configured on the interface.
In this scenario the IPv6 packets that ingress the CE from within the
CE AS are over an IPv4-Only interface and are forwarded to an IPv6
NLRI destination prefix learned from the Pure Transport Single IPv4
BGP Peer. In the IPv4-Only Edge peering architecture the PE is
IPv4-Only as all PE-CE interfaces are IPv4-Only. However, on the CE,
the PE-CE interface is the only interface that is IPv4-Only and all
other interfaces may or may not be IPv4-Only. Following the data
plane packet flow, IPv6 packets are forwarded from the ingress CE to
the IPv4-Only ingress PE where the VPN label imposition push per
prefix, per-vrf, per-CE occurs and the labeled packet is forwarded
over a 4to6 softwire IPv6-Only core, to the egress PE where the VPN
label disposition pop occurs and the native IPv6 packet is forwarded
to the egress CE. In the reverse direction IPv6 packets are
forwarded from the egress CE to egress PE where the VPN label
imposition per prefix, per-vrf, per-CE push occurs and the labeled
packet is forwarded back over the 4to6 softwire IPv6-Only core, to
the ingress PE where the VPN label disposition pop occurs and the
native IPv6 packet is forwarded to the ingress CE. . The
functionality of the IPv4 forwarding plane in this scenario is
identical from a data plane forwarding perspective to Dual Stack IPv4
/ IPv6 forwarding scenario.
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+--------+ +--------+
| IPv4 | | IPv4 |
| Client | | Client |
| Network| | Network|
+--------+ +--------+
| \ / |
| \ / |
| \ / |
| X |
| / \ |
| / \ |
| / \ |
+--------+ +--------+
| AFBR | | AFBR |
+--| IPv4/6 |---| IPv4/6 |--+
| +--------+ +--------+ |
+--------+ | | +--------+
| IPv6 | | | | IPv6 |
| Client | | | | Client |
| Network|------| IPv6 |-------| Network|
+--------+ | only | +--------+
| |
| +--------+ +--------+ |
+--| AFBR |---| AFBR |--+
| IPv4/6 | | IPv4/6 |
+--------+ +--------+
| \ / |
| \ / |
| \ / |
| X |
| / \ |
| / \ |
| / \ |
+--------+ +--------+
| IPv4 | | IPv4 |
| Client | | Client |
| Network| | Network|
+--------+ +--------+
Figure 3: 4to6 Softwire - IPv4 Edge over an IPv6-Only Core
5. RFC5549 and RFC8950 Applicability to IPv4-Only PE Design
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5.1. IPv4-Only Edge Peering design next-hop encoding
This section describes [RFC8950] next hop encoding updates to
[RFC5549] applicability to this specification. IPv4-Only eBGP Edge
PE-CE peering to carry IPv4 Unicast NLRI <AFI/SAFI> IPv4 <1/1> over
an IPv6 next hop BGP capability extended hop encoding IANA capability
codepoint value 5 defined is applicable to both [RFC5549] and
[RFC8950] as IPv4 Unicast NLRI <AFI/SAFI> IPv4 <1/1> does not change
in the RFC updates.
IPv4 packets over an IPv6-Only core 4to6 Softwire E2E packet flow is
part of the IPv6-Only PE design and this same style next hop encoding
applies to 6to4 Softwire IPv6 NLRI over IPv4 next hop with 4 byte
Next hop encoding and not IPv4 mapped IPv6 address. [RFC8950]
updates [RFC5549] for <AFI/SAFI> VPN-IPV4 <1/128>, and Multicasat VPN
<1/129>
5.2. IPv4-Only PE Design Next Hop Encoding
This section describes IPv4 Next Hop Encoding for IPv6 NLRI over an
IPv4 Next hop.
With the IPv4-Only PE design, IPv6 NLRI will be carried over an IPv4
Next-hop. [RFC4798] and [RFC4659] specify how an IPv4 address can be
encoded inside the next-hop IPv6 address field when IPv6 NLRI needs
to be advertised with an IPv4 next hop. [RFC4798] defines how the
IPv4-mapped IPv6 address format specified in the IPv6 addressing
architecture [RFC4798] can be used for that purpose when the <AFI/
SAFI> is IPv6-Unicast <2/1>, Multicast <2/2>, and Labeled Unicast
<2/4>. [RFC4659] defines how the IPv4-mapped IPv6 address format as
well as a null Route Distinguisher as ::FFFF:192.168.1.1 (RD) can be
used for that purpose when the <AFI/SAFI> is VPN-IPv6 <2/128> MVPN-
IPv6 <2/129>. This IPv4-Only PE specification utilizes IPv6 NLRI
over IPv4 Next hop encoding adopted by the industy to not use IPv4
mapped IPv6 address defined above, and instead use 4 byte IPv4
address for the next hop which ultimately set the precedence for the
adoption of [RFC8950] for 4to6 Softwire IPv4 NLRI over IPv6 next-hop.
The IPv4 next hop encoding for cases where the NLRI advertised is
different from the next hop encoding such as where IPv6 NLRI is
advertied with IPv4 next hop for for <AFI/SAFI> is IPv6-Unicast
<2/1>, Multicast <2/2>, and Labeled Unicast <2/4>. [RFC4659] defines
Null(RD) for <AFI/SAFI> is VPN-IPv6 <2/128> MVPN-IPv6 <2/129> but now
with a an official new IANA Capability code TBD as value 10 "IPv4
Next Hop Encoding". The IETF standards have not been updated with an
IANA allocation Capability code for the IPv4 next hop encoding so
this specification fixes that with an IANA allocated codepoint which
will now be used for any eBGP or iBGP peering as well as the
IPv4-Only PE design defined in this specification.
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With this specification when VPN-IPv6 AFI/SAFI 2/128, MVPN-IPv6 AFI/
SAFI 2/129 is used, the next-hop address is encoded as an IPv4
address with a length of 12 bytes. The next-hop address is now
encoded for VPN-IPv6 AFI/SAFI with a length of 12 bytes. The 12 byte
next hop includes 4 byte IPv4 address plus 8 byte Route
Distinguisher. This document modifies how the next-hop address is
encoded to accommodate all existing implementations and bring
consistency with VPN-IPv6, MVPN-IPv6 and 6PE. As all known and
deployed implementations are interoperable today and use the new
proposed encoding, the change does not break existing
interoperability. This change is applicable to all iBGP and eBGP
peering as well as the IPv4-Only PE, PE-CE edge and Inter-AS peering
design for the IPv4 next hop encoding E2E test case of IPv4 packets
over and IPv4-Only core 6to4 Softwire. In this test case IPv6
Unicast NLRI <AFI/SAFI> IPv4 <1/1> is advertised over the PE to RR
core peering 6to4 softwire in <AFI/SAFI> VPN-IPV6 <2/128> MVPN-IPv6
<2/129>. In this test cases label allocation mode comes into play
which is discussed in a subsequent section.
This document defines with the new IANA BGP Capability codepoint
allocation next hop encoding of MP_REACH_NLRI with:
* Specifically, this document allows advertising the MP_REACH_NLRI
attribute [RFC2545] with this content:
Advertising with [RFC2545] MP_REACH_NLRI with:
* AFI = 2
* SAFI = 1, 2 or 4
* Length of Next Hop Address = 4
* Specifically, this document allows advertising the MP_REACH_NLRI
attribute [RFC2545] with this content:
Advertising with [RFC2545] MP_REACH_NLRI with:
* AFI = 2
* SAFI = 128 or 129
* Length of Next Hop Address = 8
* Next Hop Address = VPN-IPv4 address of next hop with an 8-octet RD
set to zero.
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6. IPv4-Only PE Design Edge E2E Design for ALL AFI/SAFI
Listed below are the following IPv4-Only PE Design ALL SAFI design
scenario's:
<AFI/SAFI> IPv4 Unicast <1/1>, IPv6 Unicast <2/1>, VPN-IPV4 <1/128>,
VPN-IPV6 <2/128>, Multicasat VPN <1/129>, Multicasat VPN <2/129>,BGP-
LU IPV4 (GRT) <1/4>
6.1. IPv4-Only PE Design All SAFI Case-1 E2E IPv4-Only PE-CE, Global
Table over IPv4-Only Core(6PE), 6to4 softwire
________
IPv4-Only _____ / \ IPv4-Only
PE / CE / \__/ \___ PE / CE
+----+ +----+ / \ +------+ +-----+
| | | | | |_ | | | |
| | | | | \ | | | |
| CE |--| PE |--\ IPv4-Only Core |----| PE |---| CE |
| | | | \0=========Underlay =======0| | | | |
+----+ +----+ \ __/ +------+ +-----+
IPv4 BGP peer \ MPLS / SR domain / IPv4 BGP peer
IPv4 forwarding \__ __ / IPv4 forwarding
IPv6 forwarding \_______/ \_____/ IPv6 forwarding
Figure 4: Design Solution-1 E2E IPv4-Only PE-CE, Global
Table over IPv4-Only Core (6PE)
6.2. IPv4-Only PE Design All SAFI Case-2 E2E IPv4-Only PE-CE, VPN over
IPv4-Only Core, 6to4 Softwire
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________
IPv4-Only _____ / \ IPv4-Only
PE / CE / \__/ \___ PE / CE
+----+ +----+ / \ +------+ +-----+
| | | | | 0====VPN Overlay Tunnel ==0| | | | |
| | | | | \ | | | |
| CE |--| PE |--\ IPv4-Only Core |----| PE |---| CE |
| | | | \0=========Underlay =======0| | | | |
+----+ +----+ \ __/ +------+ +-----+
IPv4 BGP peer \ MPLS / SR domain / IPv4 BGP peer
IPv4 forwarding \__ __ / IPv4 forwarding
IPv6 forwarding \_______/ \_____/ IPv6 forwarding
Figure 5: Design Solution-2 E2E IPv4-Only PE-CE, VPN over
IPv4-Only Core
Huawei: Edge and Core-VRPv8, Release VRP-V800R020C10
6.3. IPv4-Only PE Design All SAFI Case-3 E2E IPv4-Only PE-CE, Global
Table over IPv6-Only Core (4PE), 4to6 Softwire
________
IPv4-Only _____ / \ IPv4-Only
PE / CE / \__/ \___ PE / CE
+----+ +----+ / \ +------+ +-----+
| | | | | |_ | | | |
| | | | | \ | | | |
| CE |--| PE |--\ IPv4-Only Core |----| PE |---| CE |
| | | | \0=========Underlay =======0| | | | |
+----+ +----+ \ __/ +------+ +-----+
IPv4 BGP peer \ MPLS / SR domain / IPv4 BGP peer
IPv4 forwarding \__ __ / IPv4 forwarding
IPv6 forwarding \_______/ \_____/ IPv6 forwarding
Figure 6: Design Solution-3 E2E IPv4-Only PE-CE, Global
Table over IPv6-Only Core (4PE)
6.4. IPv4-Only PE Design All SAFI Case-4 E2E IPv4-Only PE-CE, VPN over
IPv6-Only Core, 4to6 Softwire
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________
IPv4-Only _____ / \ IPv4-Only
PE / CE / \__/ \___ PE / CE
+----+ +----+ / \ +------+ +-----+
| | | | | 0====VPN Overlay Tunnel ==0| | | | |
| | | | | \ | | | |
| CE |--| PE |--\ IPv4-Only Core |----| PE |---| CE |
| | | | \0=========Underlay =======0| | | | |
+----+ +----+ \ __/ +------+ +-----+
IPv4 BGP peer \ MPLS / SR domain / IPv4 BGP peer
IPv4 forwarding \__ __ / IPv4 forwarding
IPv6 forwarding \_______/ \_____/ IPv6 forwarding
Figure 7: Design Solution-4 E2E IPv4-Only PE-CE, VPN over
IPv6-Only Core
6.5. IPv4-Only PE Design All SAFI Case-5 E2E IPv4-Only PE-CE, Global
Table over IPv4-Only Core(6PE), 6to4 softwire -Inter-AS Option-B
Inter-AS ASBR-ASBR link is IPv6-Only PE
IPv6-Only __________ __________ IPv6-Only
PE / CE / \ / \ PE / CE
+--+ +----+ / \ / \ +--+ +--+
| | | | | AS 1 \ | AS 2 \ | | | |
| | | | | \IPv6| \ | | | |
|CE|-| PE |--| IPv4-Only Core|----|IPv4-Only Core|--|PE|-|CE|
| | | | |0=Underlay==0 | |0==Underlay==0| | | | |
+--+ +----+ \ / \ / +--+ +--+
IPv6 BGP peer \ MPLS/SR / \ MPLS/SR / IPv6 BGP peer
IPv4 forwarding \_________/ \_________/ IPv4 forwarding
IPv6 forwarding IPv6 forwarding
Figure 8: Design Solution-5 E2E IPv4-Only PE-CE, Global
Table over IPv4-Only Core (6PE) - Inter-AS Option-B
6.6. IPv4-Only PE Design All SAFI Case-6 E2E IPv4-Only PE-CE, Global
Table over IPv4-Only Core(6PE), 6to4 softwire -Inter-AS Option-C
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Inter-AS ASBR-ASBR link is IPv6-Only PE
IPv6-Only __________ __________ IPv6-Only
PE / CE / \ / \ PE / CE
+--+ +----+ / \ / \ +--+ +--+
| | | | | AS 1 \ | AS 2 \ | | | |
| | | | | \IPv6| \ | | | |
|CE|-| PE |--| IPv4-Only Core|----|IPv4-Only Core|--|PE|-|CE|
| | | | |0=Underlay==0 | |0==Underlay==0| | | | |
+--+ +----+ \ / \ / +--+ +--+
IPv6 BGP peer \ MPLS/SR / \ MPLS/SR / IPv6 BGP peer
IPv4 forwarding \_________/ \_________/ IPv4 forwarding
IPv6 forwarding IPv6 forwarding
Figure 9: Design Solution-6 E2E IPv4-Only PE-CE, Global
Table over IPv4-Only Core (6PE) - Inter-AS Option-C
6.7. IPv4-Only PE Design All SAFI Case-7 E2E IPv4-Only PE-CE, VPN over
IPv4-Only, 6to4 softwire -Inter-AS Option-B
Inter-AS ASBR-ASBR link is IPv6-Only PE
IPv6-Only __________ __________ IPv6-Only
PE / CE / \ / \ PE / CE
+--+ +----+ / \ / \ +--+ +--+
| | | | | AS 1 \ | AS 2 \ | | | |
| | | | | \IPv6| \ | | | |
|CE|-| PE |--| IPv4-Only Core|----|IPv4-Only Core|--|PE|-|CE|
| | | | |0=Overlay===0 | |0==Overlay===0| | | | |
+--+ +----+ \ / \ / +--+ +--+
IPv6 BGP peer \ MPLS/SR / \ MPLS/SR / IPv6 BGP peer
IPv4 forwarding \_________/ \_________/ IPv4 forwarding
IPv6 forwarding IPv6 forwarding
Figure 10: Design Solution-7 E2E IPv4-Only PE-CE, VPN over
IPv4-Only Core - Inter-AS Option-B
6.8. IPv4-Only PE Design All SAFI Case-8 E2E IPv4-Only PE-CE, VPN over
IPv4-Only Core, 6to4 softwire -Inter-AS Option-C
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Inter-AS ASBR-ASBR link is IPv6-Only PE
IPv6-Only __________ __________ IPv6-Only
PE / CE / \ / \ PE / CE
+--+ +----+ / \ / \ +--+ +--+
| | | | | AS 1 \ | AS 2 \ | | | |
| | | | | \IPv6| \ | | | |
|CE|-| PE |--| IPv4-Only Core|----|IPv4-Only Core|--|PE|-|CE|
| | | | |0=Overlay===0 | |0==Overlay===0| | | | |
+--+ +----+ \ / \ / +--+ +--+
IPv6 BGP peer \ MPLS/SR / \ MPLS/SR / IPv6 BGP peer
IPv4 forwarding \_________/ \_________/ IPv4 forwarding
IPv6 forwarding IPv6 forwarding
Figure 11: Design Solution-8 E2E IPv4-Only PE-CE, VPN over
IPv4-Only Core - Inter-AS Option-C
6.9. IPv4-Only PE Design All SAFI Case-9 E2E IPv4-Only PE-CE, Global
Table over IPv6-Only Core, 4to6 softwire -Inter-AS Option-B
Inter-AS ASBR-ASBR link is IPv6-Only PE
IPv6-Only __________ __________ IPv6-Only
PE / CE / \ / \ PE / CE
+--+ +----+ / \ / \ +--+ +--+
| | | | | AS 1 \ | AS 2 \ | | | |
| | | | | \IPv6| \ | | | |
|CE|-| PE |--| IPv6-Only Core|----|IPv6-Only Core|--|PE|-|CE|
| | | | |0=Underlay==0 | |0==Underlay==0| | | | |
+--+ +----+ \ / \ / +--+ +--+
IPv6 BGP peer \ MPLS/SR / \ MPLS/SR / IPv6 BGP peer
IPv4 forwarding \_________/ \_________/ IPv4 forwarding
IPv6 forwarding IPv6 forwarding
Figure 12: Design Solution-9 E2E IPv4-Only PE-CE, Global
Table over IPv6-Only Core - Inter-AS Option-B
6.10. IPv4-Only PE Design All SAFI Case-10 E2E IPv4-Only PE-CE, Global
Table over IPv6-Only Core, 4to6 softwire -Inter-AS Option-C
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Inter-AS ASBR-ASBR link is IPv6-Only PE
IPv6-Only __________ __________ IPv6-Only
PE / CE / \ / \ PE / CE
+--+ +----+ / \ / \ +--+ +--+
| | | | | AS 1 \ | AS 2 \ | | | |
| | | | | \IPv6| \ | | | |
|CE|-| PE |--| IPv6-Only Core|--- |IPv6-Only Core|--|PE|-|CE|
| | | | |0=Underlay==0 | |0==Underlay==0| | | | |
+--+ +----+ \ / \ / +--+ +--+
IPv6 BGP peer \ MPLS/SR / \ MPLS/SR / IPv6 BGP peer
IPv4 forwarding \_________/ \_________/ IPv4 forwarding
IPv6 forwarding IPv6 forwarding
Figure 13: Design Solution-10 E2E IPv4-Only PE-CE, Global
Table over IPv6-Only Core - Inter-AS Option-C
6.11. IPv4-Only PE Design All SAFI Case-11 E2E IPv4-Only PE-CE, VPN
over IPv6-Only Core, 4to6 softwire -Inter-AS Option-B
Inter-AS ASBR-ASBR link is IPv6-Only PE
IPv6-Only __________ __________ IPv6-Only
PE / CE / \ / \ PE / CE
+--+ +----+ / \ / \ +--+ +--+
| | | | | AS 1 \ | AS 2 \ | | | |
| | | | | \IPv6| \ | | | |
|CE|-| PE |--| IPv6-Only Core|--- |IPv6-Only Core|--|PE|-|CE|
| | | | |0=Overlay===0 | |0==Overlay===0| | | | |
+--+ +----+ \ / \ / +--+ +--+
IPv6 BGP peer \ MPLS/SR / \ MPLS/SR / IPv6 BGP peer
IPv4 forwarding \_________/ \_________/ IPv4 forwarding
IPv6 forwarding IPv6 forwarding
Figure 14: Design Solution-11 E2E IPv4-Only PE-CE, VPN over
IPv6-Only Core - Inter-AS Option-B
6.12. IPv4-Only PE Design All SAFI Case-12 E2E IPv4-Only PE-CE, VPN
over IPv6-Only Core, 4to6 softwire -Inter-AS Option-C
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Inter-AS ASBR-ASBR link is IPv6-Only PE
IPv6-Only __________ __________ IPv6-Only
PE / CE / \ / \ PE / CE
+--+ +----+ / \ / \ +--+ +--+
| | | | | AS 1 \ | AS 2 \ | | | |
| | | | | \IPv6| \ | | | |
|CE|-| PE |--| IPv6-Only Core|--- |IPv6-Only Core|--|PE|-|CE|
| | | | |0=Overlay===0 | |0==Overlay===0| | | | |
+--+ +----+ \ / \ / +--+ +--+
IPv6 BGP peer \ MPLS/SR / \ MPLS/SR / IPv6 BGP peer
IPv4 forwarding \_________/ \_________/ IPv4 forwarding
IPv6 forwarding IPv6 forwarding
Figure 15: Design Solution-12 E2E IPv4-Only PE-CE, VPN over
IPv6-Only Core - Inter-AS Option-C
7. IPv6-Only PE Design ALL AFI/SFI Operational Considerations
With a single IPv6 Peer carrying both IPv4 and IPv6 NLRI there are
some operational considerations in terms of what changes and what
does not change.
What does not change with a single IPv6 transport peer carrying IPv4
NLRI and IPv6 NLRI below:
Routing Policy configuration is still separate for IPv4 and IPv6
configured by capability as previously.
Layer 1, Layer 2 issues such as one-way fiber or fiber cut will
impact both IPv4 and IPv6 as previously.
If the interface is in the Admin Down state, the IPv6 peer would go
down, and IPv4 NLRI and IPv6 NLRI would be withdrawn as previously.
Changes resulting from a single IPv6 transport peer carrying IPv4
NLRI and IPv6 NLRI below:
Physical interface is no longer dual stacked.
Any change in IPv6 address or DAD state will impact both IPv4 and
IPv6 NLRI exchange.
Single BFD session for both IPv4 and IPv6 NLRI fate sharing as the
session is now tied to the transport, which now is only IPv6 address
family.
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Both IPv4 and IPv6 peer now exists under the IPv6 address family
configuration.
Fate sharing of IPv4 and IPv6 address family from a logical
perspective now carried over a single physical IPv6 peer.
From an operations perspective, prior to elimination of IPv4 peers,
an audit is recommended to identify and IPv4 and IPv6 peering
incongruencies that may exist and to rectify them. No operational
impacts or issues are expected with this change.
With MPLS VPN overlay, per-CE next-hop label allcoation mode where
both IPv4 and IPv6 prefixes have the same label in no table lookup
pop-n-forward mode should be taken into consideration.
8. IANA Considerations
There are not any IANA considerations.
9. Security Considerations
The extensions defined in this document allow BGP to propagate
reachability information about IPv4 prefixes over an MPLS or SR
IPv6-Only core network. As such, no new security issues are raised
beyond those that already exist in BGP-4 and the use of MP-BGP for
IPv6. Both IPv4 and IPv6 peers exist under the IPv6 address family
configuration. The security features of BGP and corresponding
security policy defined in the ISP domain are applicable. For the
inter-AS distribution of IPv6 routes according to case (a) of
Section 4 of this document, no new security issues are raised beyond
those that already exist in the use of eBGP for IPv6 [RFC2545].
10. Acknowledgments
Thanks to Kaliraj Vairavakkalai, Linda Dunbar, Aijun Wang, Eduardfor
Vasilenko, Joel Harlpern, Michael McBride, Ketan Talaulikar for
review comments.
11. Contributors
The following people contributed substantive text to this document:
Mohana Sundari
EMail: mohanas@juniper.net
12. References
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12.1. Normative References
[I-D.mishra-bess-ipv4-only-pe-design]
Mishra, G. and J. Tantsura, "IPv4-Only PE Design for
IPv6-NLRI with IPv4-NH", Work in Progress, Internet-Draft,
draft-mishra-bess-ipv4-only-pe-design-01, 18 May 2022,
<https://www.ietf.org/archive/id/draft-mishra-bess-ipv4-
only-pe-design-01.txt>.
[I-D.nalawade-kapoor-tunnel-safi]
Nalawade, G., "BGP Tunnel SAFI", Work in Progress,
Internet-Draft, draft-nalawade-kapoor-tunnel-safi-05, 29
June 2006, <https://www.ietf.org/archive/id/draft-
nalawade-kapoor-tunnel-safi-05.txt>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC2545] Marques, P. and F. Dupont, "Use of BGP-4 Multiprotocol
Extensions for IPv6 Inter-Domain Routing", RFC 2545,
DOI 10.17487/RFC2545, March 1999,
<https://www.rfc-editor.org/info/rfc2545>.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, DOI 10.17487/RFC4291, February
2006, <https://www.rfc-editor.org/info/rfc4291>.
[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
2006, <https://www.rfc-editor.org/info/rfc4364>.
[RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
"Multiprotocol Extensions for BGP-4", RFC 4760,
DOI 10.17487/RFC4760, January 2007,
<https://www.rfc-editor.org/info/rfc4760>.
[RFC4761] Kompella, K., Ed. and Y. Rekhter, Ed., "Virtual Private
LAN Service (VPLS) Using BGP for Auto-Discovery and
Signaling", RFC 4761, DOI 10.17487/RFC4761, January 2007,
<https://www.rfc-editor.org/info/rfc4761>.
[RFC5195] Ould-Brahim, H., Fedyk, D., and Y. Rekhter, "BGP-Based
Auto-Discovery for Layer-1 VPNs", RFC 5195,
DOI 10.17487/RFC5195, June 2008,
<https://www.rfc-editor.org/info/rfc5195>.
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[RFC5492] Scudder, J. and R. Chandra, "Capabilities Advertisement
with BGP-4", RFC 5492, DOI 10.17487/RFC5492, February
2009, <https://www.rfc-editor.org/info/rfc5492>.
[RFC5747] Wu, J., Cui, Y., Li, X., Xu, M., and C. Metz, "4over6
Transit Solution Using IP Encapsulation and MP-BGP
Extensions", RFC 5747, DOI 10.17487/RFC5747, March 2010,
<https://www.rfc-editor.org/info/rfc5747>.
[RFC6037] Rosen, E., Ed., Cai, Y., Ed., and IJ. Wijnands, "Cisco
Systems' Solution for Multicast in BGP/MPLS IP VPNs",
RFC 6037, DOI 10.17487/RFC6037, October 2010,
<https://www.rfc-editor.org/info/rfc6037>.
[RFC7117] Aggarwal, R., Ed., Kamite, Y., Fang, L., Rekhter, Y., and
C. Kodeboniya, "Multicast in Virtual Private LAN Service
(VPLS)", RFC 7117, DOI 10.17487/RFC7117, February 2014,
<https://www.rfc-editor.org/info/rfc7117>.
[RFC7267] Martini, L., Ed., Bocci, M., Ed., and F. Balus, Ed.,
"Dynamic Placement of Multi-Segment Pseudowires",
RFC 7267, DOI 10.17487/RFC7267, June 2014,
<https://www.rfc-editor.org/info/rfc7267>.
[RFC7432] Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A.,
Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based
Ethernet VPN", RFC 7432, DOI 10.17487/RFC7432, February
2015, <https://www.rfc-editor.org/info/rfc7432>.
[RFC7752] Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and
S. Ray, "North-Bound Distribution of Link-State and
Traffic Engineering (TE) Information Using BGP", RFC 7752,
DOI 10.17487/RFC7752, March 2016,
<https://www.rfc-editor.org/info/rfc7752>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8277] Rosen, E., "Using BGP to Bind MPLS Labels to Address
Prefixes", RFC 8277, DOI 10.17487/RFC8277, October 2017,
<https://www.rfc-editor.org/info/rfc8277>.
[RFC8955] Loibl, C., Hares, S., Raszuk, R., McPherson, D., and M.
Bacher, "Dissemination of Flow Specification Rules",
RFC 8955, DOI 10.17487/RFC8955, December 2020,
<https://www.rfc-editor.org/info/rfc8955>.
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[RFC9012] Patel, K., Van de Velde, G., Sangli, S., and J. Scudder,
"The BGP Tunnel Encapsulation Attribute", RFC 9012,
DOI 10.17487/RFC9012, April 2021,
<https://www.rfc-editor.org/info/rfc9012>.
[RFC9015] Farrel, A., Drake, J., Rosen, E., Uttaro, J., and L.
Jalil, "BGP Control Plane for the Network Service Header
in Service Function Chaining", RFC 9015,
DOI 10.17487/RFC9015, June 2021,
<https://www.rfc-editor.org/info/rfc9015>.
12.2. Informative References
[I-D.ietf-idr-dynamic-cap]
Chen, E. and S. R. Sangli, "Dynamic Capability for BGP-4",
Work in Progress, Internet-Draft, draft-ietf-idr-dynamic-
cap-16, 21 October 2021, <https://www.ietf.org/archive/id/
draft-ietf-idr-dynamic-cap-16.txt>.
[RFC4659] De Clercq, J., Ooms, D., Carugi, M., and F. Le Faucheur,
"BGP-MPLS IP Virtual Private Network (VPN) Extension for
IPv6 VPN", RFC 4659, DOI 10.17487/RFC4659, September 2006,
<https://www.rfc-editor.org/info/rfc4659>.
[RFC4684] Marques, P., Bonica, R., Fang, L., Martini, L., Raszuk,
R., Patel, K., and J. Guichard, "Constrained Route
Distribution for Border Gateway Protocol/MultiProtocol
Label Switching (BGP/MPLS) Internet Protocol (IP) Virtual
Private Networks (VPNs)", RFC 4684, DOI 10.17487/RFC4684,
November 2006, <https://www.rfc-editor.org/info/rfc4684>.
[RFC4798] De Clercq, J., Ooms, D., Prevost, S., and F. Le Faucheur,
"Connecting IPv6 Islands over IPv4 MPLS Using IPv6
Provider Edge Routers (6PE)", RFC 4798,
DOI 10.17487/RFC4798, February 2007,
<https://www.rfc-editor.org/info/rfc4798>.
[RFC4925] Li, X., Ed., Dawkins, S., Ed., Ward, D., Ed., and A.
Durand, Ed., "Softwire Problem Statement", RFC 4925,
DOI 10.17487/RFC4925, July 2007,
<https://www.rfc-editor.org/info/rfc4925>.
[RFC5549] Le Faucheur, F. and E. Rosen, "Advertising IPv4 Network
Layer Reachability Information with an IPv6 Next Hop",
RFC 5549, DOI 10.17487/RFC5549, May 2009,
<https://www.rfc-editor.org/info/rfc5549>.
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[RFC5565] Wu, J., Cui, Y., Metz, C., and E. Rosen, "Softwire Mesh
Framework", RFC 5565, DOI 10.17487/RFC5565, June 2009,
<https://www.rfc-editor.org/info/rfc5565>.
[RFC6074] Rosen, E., Davie, B., Radoaca, V., and W. Luo,
"Provisioning, Auto-Discovery, and Signaling in Layer 2
Virtual Private Networks (L2VPNs)", RFC 6074,
DOI 10.17487/RFC6074, January 2011,
<https://www.rfc-editor.org/info/rfc6074>.
[RFC6513] Rosen, E., Ed. and R. Aggarwal, Ed., "Multicast in MPLS/
BGP IP VPNs", RFC 6513, DOI 10.17487/RFC6513, February
2012, <https://www.rfc-editor.org/info/rfc6513>.
[RFC6514] Aggarwal, R., Rosen, E., Morin, T., and Y. Rekhter, "BGP
Encodings and Procedures for Multicast in MPLS/BGP IP
VPNs", RFC 6514, DOI 10.17487/RFC6514, February 2012,
<https://www.rfc-editor.org/info/rfc6514>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
[RFC8950] Litkowski, S., Agrawal, S., Ananthamurthy, K., and K.
Patel, "Advertising IPv4 Network Layer Reachability
Information (NLRI) with an IPv6 Next Hop", RFC 8950,
DOI 10.17487/RFC8950, November 2020,
<https://www.rfc-editor.org/info/rfc8950>.
Authors' Addresses
Gyan Mishra
Verizon Inc.
Email: gyan.s.mishra@verizon.com
Jeff Tantsura
Microsoft, Inc.
Email: jefftant.ietf@gmail.com
Mankamana Mishra
Cisco Systems
821 Alder Drive,
MILPITAS
Email: mankamis@cisco.com
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Sudha Madhavi
Juniper Networks, Inc.
Email: smadhavi@juniper.net
Qing Yang
Arista Networks
Email: qyang@arista.com
Adam Simpson
Nokia
Email: adam.1.simpson@nokia.com
Shuanglong Chen
Huawei Technologies
Email: chenshuanglong@huawei.com
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