BESS Workgroup J. Rabadan, Ed.
Internet Draft K. Nagaraj
Intended status: Standards Track Nokia
W. Lin
Juniper
A. Sajassi
Cisco
Expires: May 4, 2020 November 1, 2019
EVPN Multi-Homing Extensions for Split Horizon Filtering
draft-nr-bess-evpn-mh-split-horizon-02
Abstract
Ethernet Virtual Private Network (EVPN) is commonly used along with
Network Virtualization Overlay (NVO) tunnels. The EVPN multi-homing
procedures may be different depending on the NVO tunnel type used in
the EVPN Broadcast Domain. In particular, there are two multi-homing
Split Horizon procedures to avoid looped frames on the multi-homed
CE: ESI Label based and Local Bias. ESI Label based Split Horizon is
used for MPLSoX tunnels, E.g., MPLSoUDP, whereas Local Bias is used
for others, E.g., VXLAN tunnels. The current specifications do not
allow the operator to decide which Split Horizon procedure to use for
tunnel encapsulations that could support both. Examples of tunnels
that may support both procedures are MPLSoGRE, MPLSoUDP, GENEVE or
SRv6.sThis document extends the EVPN Multi-Homing procedures so that
an operator can decide the Split Horizon procedure for a given NVO
tunnel depending on their own requirements.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts.
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This Internet-Draft will expire on May 4, 2020.
Copyright Notice
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Conventions and Terminology . . . . . . . . . . . . . . . . 5
2. BGP EVPN Extensions . . . . . . . . . . . . . . . . . . . . . . 7
2.1 The Split Horizon Type (SHT) . . . . . . . . . . . . . . . . 8
2.2 Use of the Split Horizon Type In A-D Per ES Routes . . . . . 8
2.3 ESI Label Value In A-D Per ES Routes . . . . . . . . . . . . 9
2.4 Backwards Compatibility With [RFC8365] NVEs . . . . . . . . 10
3. Procedures for NVEs Supporting Multiple Encapsulations . . . . 11
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 12
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12
8.1. Normative References . . . . . . . . . . . . . . . . . . . 12
8.2. Informative References . . . . . . . . . . . . . . . . . . 13
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 14
10. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14
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1. Introduction
Ethernet Virtual Private Network (EVPN) is commonly used along with
Network Virtualization Overlay (NVO) tunnels and specified in
[RFC8365]. The EVPN multi-homing procedures may be different
depending on the NVO tunnel type used in the EVPN Broadcast Domain.
In particular, there are two Multi-Homing Split Horizon procedures to
avoid looped frames on the multi-homed CE: ESI Label based and Local
Bias. ESI Label based Split Horizon is used for MPLSoX tunnels, E.g.,
MPLSoUDP [RFC7510], and its procedures described in [RFC7432]. Local
Bias is used by non-MPLS NVO tunnels, E.g., VXLAN tunnels, and it is
described in [RFC8365].
As a refresher:
o ESI Label based Split-Horizon filtering [RFC7432]
If MPLS-based tunnels are used in EVPN, an MPLS label is used for
Split Horizon filtering to support All-Active multi-homing where an
ingress NVE adds a label corresponding to the source Ethernet
Segment (aka an ESI label) when encapsulating the packet. The
egress NVE checks the ESI label when attempting to forward a multi-
destination frame out a local ES interface, and if the label
corresponds to the same site identifier (ESI) associated with that
ES interface, the packet is not forwarded. This prevents the
occurrence of forwarding loops for BUM traffic.
The ESI Label Split Horizon filtering SHOULD also be used with
Single-Active multi-homing to avoid transient loops for in-flight
packets when the egress NVE takes over as DF for an Ethernet
Segment.
o Local Bias for non-MPLS NVO tunnels [RFC8365]
Since non-MPLS NVO tunnels, such as VXLAN and NVGRE encapsulations,
do not include the ESI label, a different Split Horizon filtering
procedure must be used for All-Active multi-homing. This mechanism
is called Local Bias and relies on the NVO tunnel source IP address
to decide whether to forward BUM traffic to a local ES interface at
the egress NVE.
In a nutshell, every NVE tracks the IP address(es) associated with
the other NVE(s) with which it has shared multi-homed ESs. When the
egress NVE receives a BUM frame encapsulated in a VXLAN or NVGRE
packet, it examines the source IP address in the tunnel header
(which identifies the ingress NVE) and filters out the frame on all
local interfaces connected to ESes that are shared with the ingress
NVE.
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Due to this behavior at the egress NVE, the ingress NVE's behavior
is also changed to perform replication locally to all directly
attached Ethernet segments (regardless of the DF election state)
for all BUM ingress from the access ACs. Because of this "local"
replication at the ingress NVE, this approach is referred to as
Local Bias.
Local Bias cannot be used for Single-Active multi-homing, since the
ingress NVE brings operationally down the ACs for which it is non-
DF (hence local replication to non-DF ACs cannot be done). This
means transient in-flight BUM packets may be looped back to the
originating site by new elected DF egress NVEs.
[RFC8365] states that Local Bias is used only for non-MPLS NVO
tunnels, and ESI Label based Split Horizon for MPLS NVO tunnels.
However, MPLS NVO tunnels, such as MPLSoGRE or MPLSoUDP, can
potentially support both procedures, since they can carry ESI Labels
and they also use a tunnel IP header where the source IP address
identifies the ingress NVE.
Similarly, some non-MPLS NVO tunnels may potentially follow either
procedure too. Some examples are GENEVE or SRv6:
o In a GENEVE tunnel the source IP address identifies the ingress NVE
therefore local bias is possible. Also, [EVPN-GENEVE] defines an
Ethernet option TLV (Type Length Value) to encode an ESI label
value.
o In an SRv6 tunnel, the source IP address also identifies the
ingress NVE, however, by default and as described in [SRv6-
Services] the ingress PE will add information in the SRv6 packet so
that the egress PE can identify the source ES of the BUM packet.
That information is the ESI filtering argument of the service SID
received on an A-D per ES route from the egress PE.
Table 1 shows different tunnel encapsulations and their supported and
default Split Horizon method. In the case of GENEVE, the default
Split Horizon Type (SHT) depends on whether the Ethernet Option with
Source ID TLV is negotiated. In the case of SRv6, the default SHT is
listed as ESI label filtering in Table 1, since the behavior is
equivalent to that of ESI Label filtering
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+-------------+------------------------+-----------+----------+
|Tunnel | Default Split Horizon | Supports |Supports |
|Encapsulation| Type (SHT) | Local Bias|ESI Label |
+-------------|------------------------|-----------|----------+
| VXLAN | Local Bias | Yes | No |
+-------------|------------------------|-----------|----------+
| NVGRE | Local Bias | Yes | No |
+-------------|------------------------|-----------|----------+
| MPLS | ESI Label filtering | No | Yes |
+-------------|------------------------|-----------|----------+
| MPLSoGRE | ESI Label filtering | Yes | Yes |
+-------------|------------------------|-----------|----------+
| MPLSoUDP | ESI Label filtering | Yes | Yes |
+-------------|------------------------|-----------|----------+
| GENEVE | Local Bias (no ESI Lb) | Yes | Yes |
| | ESI Label (if ESI Lb) | | |
+-------------|------------------------|-----------|----------+
| SRv6 | ESI Label filtering | Yes | Yes |
+-------------+------------------------+-----------+----------+
Table 1 - Tunnel Encapsulations and Split Horizon Types
The ESI Label method works for All-Active and Single-Active, while
Local Bias only works for All-Active. In addition, the ESI Label
method works across different networks, whereas Local Bias is limited
to networks with no next hop change between the NVEs in the same
Ethernet Segment. However, some operators prefer the Local Bias
method, since it simplifies the encapsulation, consumes less
resources on the NVEs and the ingress NVE always forwards locally to
other interfaces.
This document extends the EVPN Multi-Homing procedures so that an
operator can decide the Split Horizon procedure for a given NVO
tunnel depending on their own specific requirements. The choice of
Local Bias or ESI Label Split Horizon is now allowed for NVO tunnels
that support both methods. Non-MPLS NVO tunnels that do not support
both methods, E.g., VXLAN or NVGRE, will follow [RFC8365]
procedures.
1.1 Conventions and Terminology
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
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14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
o BUM: Broadcast, Unknown unicast and Multicast traffic.
o ES and ESI: Ethernet Segment and Ethernet Segment Identifier.
o A-D per ES route: refers to the EVPN Ethernet Auto-Discovery per
Ethernet Segment route defined in [RFC7432].
o AC: Attachment Circuit.
o NVE: Network Virtualization Edge device.
o EVI and EVI-RT: EVPN Instance and EVI Route Target. A group of NVEs
attached to the same EVI will share the same EVI-RT.
o MPLS and non-MPLS NVO tunnels: refer to Multi-Protocol Label
Switching (or the absence of it) Network Virtualization Overlay
tunnels. Network Virtualization Overlay tunnels use an IP
encapsulation for overlay frames, where the source IP address
identifies the ingress NVE and the destination IP address the
egress NVE.
o MPLSoUDP: Multi-Protocol Label Switching over User Datagram
Protocol, [RFC7510]
o MPLSoGRE: Multi-Protocol Label Switching over Generic Network
Encapsulation, [RFC4023].
o MPLSoX: refers to MPLS over any IP encapsulation. Examples are
MPLSoUDP or MPLSoGRE.
o GENEVE: Generic Network Virtualization Encapsulation, [GENEVE].
o VXLAN: Virtual eXtensible Local Area Network, [RFC7348].
o NVGRE: Network Virtualization Using Generic Routing Encapsulation,
[RFC7637].
o VNI: Virtual Network Identifier. A 24-bit identifier used by
Network Virtualization Overlay (NVO) over IP encapsulations.
Examples are VXLAN (Virtual Extended Local Area Network) or GENEVE
(Generic Network Virtualization Encapsulation).
o Broadcast Domain (BD): an emulated ethernet, such that two systems
on the same BD will receive each other's link-local broadcasts. In
this document, BD also refers to the instantiation of a Broadcast
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Domain on an EVPN PE. An EVPN PE can be attached to one or multiple
BDs of the same tenant.
o Designated Forwarder (DF): as defined in [RFC7432], an ethernet
segment may be multi-homed (attached to more than one PE). An
ethernet segment may also contain multiple BDs, of one or more
EVIs. For each such EVI, one of the PEs attached to the segment
becomes that EVI's DF for that segment. Since a BD may belong to
only one EVI, we can speak unambiguously of the BD's DF for a given
segment.
o SHT: Split Horizon Type, it refers to the Split Horizon method that
a PE intends to use and advertises in an A-D per ES route.
This document also assumes familiarity with the terminology of
[RFC7432] and [RFC8365].
2. BGP EVPN Extensions
EVPN extensions are needed so that NVEs can advertise their
preference for the Split Horizon method to be used in the Ethernet
Segment. Figure 1 shows the ESI Label extended community that is
always advertised along with the EVPN A-D per ES route. All the NVEs
attached to an Ethernet Segment advertise an A-D per ES route for the
ES, including this extended community that conveys the information
for the multi-homing mode (All-active or Single-Active), as well as
the ESI Label to be used (if needed).
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=0x06 | Sub-Type=0x01 | Flags(1 octet)| Reserved=0 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved=0 | ESI Label |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1 - ESI Label extended community
[RFC7432] defines the low-order bit of the Flags octet (bit 0) as the
"Single-Active" bit:
o A value of 0 means that the multi-homed Ethernet Segment is
operating in All-Active mode.
o A value of 1 means that the multi-homed Ethernet Segment is
operating in Single-Active mode.
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2.1 The Split Horizon Type (SHT)
[RFC8365] does not add any explicit indication about the Split
Horizon method in the A-D per ES route. In this document the
[RFC8365] Split Horizon procedure is the default behavior and assumes
that Local Bias is used only for non-MPLS NVO tunnels, and ESI Label
based Split Horizon for MPLS NVO tunnels. This document defines the
two high-order bits in the Flags octet (bits 6 and 7) as the "Split
Horizon Type" (SHT) field, where:
SHT bit 7 6
-----------
0 0 --> Default SHT. Backwards compatible with [RFC8365]
0 1 --> Local Bias
1 0 --> ESI Label based filtering
1 1 --> reserved for future use
o SHT = 00 is backwards compatible with [RFC8365] and indicates:
- The advertising NVE intends to use the default or native SHT. The
default SHT is shown in Table 1 for each NVO encapsulation.
- An egress NVE that follows the [RFC8365] behavior and does not
support this specification will use an SHT value of 00.
o SHT = 01 indicates that the advertising NVE intends to use Local
Bias procedures in the Ethernet Segment for which the AD per-ES
route is advertised.
o SHT = 10 indicates that the advertising NVE intends to use the ESI
Label based Split Horizon method procedures in the Ethernet Segment
for which the AD per-ES route is advertised.
2.2 Use of the Split Horizon Type In A-D Per ES Routes
The following must be observed:
- An SHT value of 01 or 10 MUST NOT be used with encapsulations that
support only one SHT in Table 1, and MAY be used by encapsulations
that support the two SHTs in Table 1.
- An SHT value different than 00 expresses the intend to use a
specific Split Horizon method, but does not reflect the actual
operational SHT used by the advertising NVE, unless all the NVEs
attached to the ES advertise the same SHT.
- In case of inconsistency in the SHT value advertised by the NVEs
attached to the same ES for a given EVI, all the NVEs MUST revert
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to the [RFC8365] behavior, and use the default SHT in Table 1,
irrespective of the advertised SHT.
- An SHT different from 00 MUST NOT be set if the Single-Active bit
is set. A received A-D per ES route where Single-Active and SHT
bits are different from zero MUST be treat-as-withdraw [RFC7606].
- The SHT MUST have the same value in each Ethernet A-D per ES route
that an NVE advertises for a given ES and a given encapsulation
(see Section 3 for NVEs supporting multiple encapsulations).
As an example, egress NVEs that support MPLS NVO tunnels, E.g.,
MPLSoGRE or MPLSoUDP, will advertise A-D per ES route(s) for the ES
along with the [RFC5512] BGP Encapsulation extended community
indicating the encapsulation (MPLSoGRE or MPLSoUDP) and MAY use the
SHT = 01 or 10 to indicate the intend to use Local Bias or ESI Label,
respectively.
An egress NVE MUST NOT use an SHT value different from 00 when
advertising an A-D per ES route with encapsulation VXLAN, NVGRE, MPLS
or no [RFC5512] BGP tunnel encapsulation extended community. We
assume that, in all these cases, there is no Split Horizon method
choice, and therefore the SHT value must be 00. A received route with
one of the above encapsulation options and SHT value different from
00 SHOULD be treat-as-withdraw.
An egress NVE advertising A-D per ES route(s) for an ES with
encapsulation GENEVE MAY use an SHT value of 01 or 10. A value of 01
indicates the intend to use Local Bias, irrespective of the presence
of an Ethernet option TLV with a non-zero Source-ID [EVPN-GENEVE]. A
value of 10 indicates the intend to use ESI Label based Split
Horizon. A value of 00 indicates the default behavior in Table 1,
that is, use Local Bias if no ESI-Label exists in the Ethernet option
TLV or no Ethernet option TLV whatsoever. Otherwise the ESI Label
Split Horizon method is used.
The above procedures assume a single encapsulation supported in the
egress NVE. Section 3 describes additional procedures for NVEs
supporting multiple encapsulations.
2.3 ESI Label Value In A-D Per ES Routes
This document also modifies the value that is advertised in the ESI
Label field of the ESI Label extended community as follows:
o The A-D per ES route(s) for an ES MAY have an ESI Label value of
zero if the SHT value is 01. Section 2.2 specifies the cases where
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the SHT can be 01. An ESI Label value of zero avoids the allocation
of Labels in the cases where they are not used (Local Bias).
o The A-D per ES route(s) for an ES MAY have an ESI Label value of
zero for VXLAN or NVGRE encapsulations.
2.4 Backwards Compatibility With [RFC8365] NVEs
As discussed in Section 2.2 this specification is backwards
compatible with the Split Horizon filtering behavior in [RFC8365] and
a non-upgraded NVE can be attached to the same ES as other NVEs
supporting this specification.
An NVE has an administrative SHT value for an ES (the one that is
advertised along with the A-D per ES route) and an operational SHT
value (the one that is actually used irrespective of what the NVE
advertised). The administrative SHT matches the operational SHT if
all the NVEs attached to the ES have the same administrative SHT.
This document assumes that an [RFC7432] or [RFC8365] compatible
implementation (that does not support this document) ignores the
value or all the bits in the ESI Label extended community except for
the Single-Active bit. Based on this assumption, a non-upgraded NVE
will ignore an SHT different from 00. As soon as an upgraded NVE
receives at least one A-D per ES route for the ES with SHT value of
00, it MUST revert its operational SHT to the default Split Horizon
method, as in Table 1, and irrespective of its administrative SHT.
As an example, consider an NVE attached to Ethernet Segment N that
receives two A-D per ES routes for N from different NVEs, NVE1 and
NVE2. If the route from NVE1 has SHT = 00 and the one from NVE2 an
SHT = 01, the NVE MUST use the default Split Horizon method in Table
1 as operational SHT, irrespective of its administrative SHT.
All the NVEs attached to an ES with operational SHT value of 10 MUST
advertise a valid non-zero ESI Label. If the operational SHT value is
01, the ESI Label MAY be zero. If the operational SHT value is 00,
the ESI Label MAY be zero only if the default encapsulation supports
Local Bias only and the NVEs do not check the presence of a valid
non-zero ESI Label.
If an NVE changes its operational SHT value from 01 to 00 (as a
result of a new non-upgraded NVE present in the ES) and it previously
advertised a zero ESI Label, it MUST send an update with a non-zero
valid ESI Label, unless all the non-upgraded NVEs in the ES support
Local Bias only.
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3. Procedures for NVEs Supporting Multiple Encapsulations
As specified by [RFC8365], an egress NVE that supports multiple data
plane encapsulations (I.e., VXLAN, NVGRE, MPLS, MPLSoUDP, GENEVE)
needs to indicate all the supported encapsulations using BGP
Encapsulation extended communities defined in [RFC5512] with all EVPN
routes. This section clarifies the multi-homing Split Horizon
behavior for NVEs advertising and receiving multiple BGP
Encapsulation extended communities along with the A-D per ES routes.
This section uses a notation of {x,y} to indicate the encapsulations
advertised in [RFC5512] BGP Encapsulation extended communities, with
x and y being different encapsulation values.
It is important to remember that an NVE MAY advertise multiple A-D
per ES routes for the same ES (and not only one), each route
conveying a number of EVI Route Targets (EVI-RTs). We refer to the
total number of EVI-RTs in a given ES as EVI-RT-set for that ES. Any
of the EVIs represented in the EVI-RT-set will have its EVI-RT
included in one (and only one) A-D per ES route for the ES. When
multiple A-D per ES routes are advertised for the same ES, each route
MUST have a different Route Distinguisher.
As per [RFC8365], an NVE that advertises multiple encapsulations in
the A-D per ES route(s) for an ES, MUST advertise encapsulations that
use the same Split Horizon filtering method in the same route. For
example:
o An A-D per ES route for ES-x may be advertised with {VXLAN,NVGRE}
encapsulations.
o An A-D per ES route for ES-y may be advertised with
{MPLS,MPLSoUDP,MPLSoGRE} encapsulations (or a subset).
o But an A-D per ES route for ES-z MUST NOT be advertised with
{MPLS,VXLAN} encapsulations.
This document extends this behavior as follows:
(a) An A-D per ES route for ES-x may be advertised with multiple
encapsulations where some support a single Split Horizon method.
In this case, the SHT value MUST be 00. As an example,
{VXLAN,NVGRE}, {VXLAN,GENEVE} or {MPLS,MPLSoGRE,MPLSoUDP} can be
advertised in an A-D per ES route. In all those cases SHT MUST be
00.
(b) An A-D per ES route for ES-y may be advertised with multiple
encapsulations where all of them support both Split Horizon
methods. In this case the SHT value MAY be 01 if the desired
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method is Local Bias, or 10 if ESI Label based. For example,
{MPLSoGRE,MPLSoUDP,GENEVE} (or a subset) may be advertised in an
A-D per ES route with SHT value of 01. The ESI Label value in
this case MAY be zero.
(c) If ES-z with EVI-RT-set composed of (EVI-RT1,EVI-RT2,EVI-
RT3..EVI-RTn) supports multiple encapsulations that require a
different Split Horizon method, a different A-D per ES route (or
group of routes) per Split Horizon method MUST be advertised. For
example, consider n EVIs in ES-z and:
- the EVIs corresponding to (EVI-RT1..EVI-RTi) support VXLAN,
- the ones for (EVI-RTi+1..EVI-RTm) (with i<m) support MPLSoUDP
with Local Bias,
- and the ones for (EVI-RTm+1..EVI-RTn) (with m<n) support GENEVE
with ESI Label based Split Horizon.
In this case, three groups of A-D per ES routes MUST be
advertised for ES-z:
- A-D per ES route group 1, including (EVI-RT1..EVI-RTi), with
encapsulation {VXLAN}, SHT = 00. The ESI Label MAY be zero.
- A-D per ES route group 2, including (EVI-RTi+1..EVI-RTm), with
encapsulation {MPLSoUDP}, SHT = 01. The ESI Label MAY be zero.
- A-D per ES route group 3, including (EVI-RTm+1..EVI-RTn), with
encapsulation {GENEVE}, SHT = 10. The ESI Label MUST have a
valid value, different from zero, and the Ethernet option
[EVPN-GENEVE] MUST be advertised.
As per [RFC8365], it is the responsibility of the operator of a given
EVI to ensure that all of the NVEs in that EVI support a common
encapsulation. If this condition is violated, it could result in
service disruption or failure.
7. IANA Considerations
IANA is requested to allocate the SHT bits (6 and 7) in the Flags
Octet of the EVPN ESI Label extended community. This field is called
"Split Horizon Type" bits.
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
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Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March
1997, <https://www.rfc-editor.org/info/rfc2119>.
[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>.
[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>.
[RFC8365] Sajassi, A., Ed., Drake, J., Ed., Bitar, N., Shekhar, R.,
Uttaro, J., and W. Henderickx, "A Network Virtualization Overlay
Solution Using Ethernet VPN (EVPN)", RFC 8365, DOI 10.17487/RFC8365,
March 2018, <https://www.rfc-editor.org/info/rfc8365>.
8.2. Informative References
[RFC8584] Rabadan-Mohanty et al., "Framework for EVPN Designated
Forwarder Election Extensibility", <https://rfc-
editor.org/rfc/rfc8584.txt>, April 2019.
[EVPN-GENEVE] Boutros, S., Sajassi, A., Drake, J., and J. Rabadan,
"EVPN control plane for Geneve", Work in Progress, draft-ietf-bess-
evpn-geneve-00, August 2019.
[RFC7348] Mahalingam, M., Dutt, D., Duda, K., Agarwal, P., Kreeger,
L., Sridhar, T., Bursell, M., and C. Wright, "Virtual eXtensible
Local Area Network (VXLAN): A Framework for Overlaying Virtualized
Layer 2 Networks over Layer 3 Networks", RFC 7348, DOI
10.17487/RFC7348, August 2014, <https://www.rfc-
editor.org/info/rfc7348>.
[RFC5512] Mohapatra, P. and E. Rosen, "The BGP Encapsulation
Subsequent Address Family Identifier (SAFI) and the BGP Tunnel
Encapsulation Attribute", RFC 5512, DOI 10.17487/RFC5512, April 2009,
<https://www.rfc-editor.org/info/rfc5512>.
[RFC4023] Worster, T., Rekhter, Y., and E. Rosen, Ed.,
"Encapsulating MPLS in IP or Generic Routing Encapsulation (GRE)",
RFC 4023, DOI 10.17487/RFC4023, March 2005, <https://www.rfc-
editor.org/info/rfc4023>.
[RFC7637] Garg, P., Ed. and Y. Wang, Ed., "NVGRE: Network
Virtualization Using Generic Routing Encapsulation", RFC 7637, DOI
10.17487/RFC7637, September 2015, <https://www.rfc-
Nagaraj, Rabadan et al Expires May 4, 2020 [Page 13]
Internet-Draft EVPN MH Split Horizon Extensions November 1, 2019
editor.org/info/rfc7637>.
[RFC7510] Xu, X., Sheth, N., Yong, L., Callon, R., and D. Black,
"Encapsulating MPLS in UDP", RFC 7510, DOI 10.17487/RFC7510, April
2015, <https://www.rfc-editor.org/info/rfc7510>.
[GENEVE] Gross, J., Ed., Ganga, I., Ed., and T. Sridhar, Ed.,
"Geneve: Generic Network Virtualization Encapsulation", Work in
Progress, draft-ietf-nvo3-geneve-14, September 2019.
[TUNNEL-ENCAP] Rosen, E., Ed., Patel, K., and G. Vesde, "The BGP
Tunnel Encapsulation Attribute", Work in Progress draft-ietf-idr-
tunnel-encaps-14, September 2019.
[RFC7606] Chen, E., Scudder, J., Mohapatra, P., and K. Patel,
"Revised Error Handling for BGP UPDATE Messages", RFC 7606, August
2015, <http://www.rfc-editor.org/info/rfc7606>.
[SRv6-Services] Dawra, G. et al., "SRv6 BGP based Overlay services",
Work in Progress, draft-ietf-bess-srv6-services-00, October 2019.
9. Acknowledgments
10. Contributors
Authors' Addresses
Jorge Rabadan (Editor)
Nokia
777 E. Middlefield Road
Mountain View, CA 94043 USA
Email: jorge.rabadan@nokia.com
Kiran Nagaraj
Nokia
701 E. Middlefield Road
Mountain View, CA 94043 USA
Email: kiran.nagaraj@nokia.com
Wen Lin
Nagaraj, Rabadan et al Expires May 4, 2020 [Page 14]
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Juniper Networks
Email: wlin@juniper.net
Ali Sajassi
Cisco Systems, Inc.
225 West Tasman Drive
San Jose, CA 95134 USA
Email: sajassi@cisco.com
Nagaraj, Rabadan et al Expires May 4, 2020 [Page 15]