EVN6: Mapping of Ethernet Virtual Network to IPv6 Underlay for Transmission
draft-xls-intarea-evn6-04
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| Document | Type | Active Internet-Draft (individual) | |
|---|---|---|---|
| Authors | Chongfeng Xie , Jibin Sun , Xing Li , Congxiao Bao , Mark Smith | ||
| Last updated | 2025-08-25 | ||
| Replaces | draft-xls-6man-evn6 | ||
| RFC stream | (None) | ||
| Intended RFC status | (None) | ||
| Formats | |||
| Stream | Stream state | (No stream defined) | |
| Consensus boilerplate | Unknown | ||
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| Send notices to | (None) |
draft-xls-intarea-evn6-04
Intarea Working Group C. Xie
Internet-Draft J. Sun
Intended status: Experimental China Telecom
Expires: 27 February 2026 X. Li
C. Bao
CERNET Center/Tsinghua University
M. Smith
26 August 2025
EVN6: Mapping of Ethernet Virtual Network to IPv6 Underlay for
Transmission
draft-xls-intarea-evn6-04
Abstract
This document describes the mechanism of mapping of Ethernet Virtual
Network to IPv6 Underlay for transmission. Unlike the existing
methods, this approach places the Ethernet frames to be transmitted
directly in the payload of IPv6 packets, i.e., L2 over IPv6, and uses
stateless mapping to generate IPv6 source and destination addresses
from the host's MAC addresses, Ethernet Virtual Network identifier
and site prefixes. The IPv6 packets generated in this way carry
Ethernet frames and are routed to the destination site across public
IPv6 network.
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). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 27 February 2026.
Copyright Notice
Copyright (c) 2025 IETF Trust and the persons identified as the
document authors. All rights reserved.
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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
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. Overall Architecture . . . . . . . . . . . . . . . . . . . . 4
4. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 6
4.1. Network Creation Procedures . . . . . . . . . . . . . . . 6
4.2. Data Transmission Procedures . . . . . . . . . . . . . . 7
4.3. Data Receiving Procedures . . . . . . . . . . . . . . . . 10
5. Multicast and Broadcast . . . . . . . . . . . . . . . . . . . 12
5.1. Multicast . . . . . . . . . . . . . . . . . . . . . . . . 12
5.2. Broadcast . . . . . . . . . . . . . . . . . . . . . . . . 13
6. Security Considerations . . . . . . . . . . . . . . . . . . . 14
7. Benefits and Advantages Analysis . . . . . . . . . . . . . . 14
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
9. Acknowledgment . . . . . . . . . . . . . . . . . . . . . . . 15
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
10.1. Normative References . . . . . . . . . . . . . . . . . . 15
10.2. Informative References . . . . . . . . . . . . . . . . . 16
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction
Ethernet Virtual Network is network model of Layer-2 built on top of
the underlay to provide connectivity between dispersed customer sites
across public network. This overlay L2 virtual network is used to
carry the Ethernet data from the individual hosts in an encapsulated
format over a logical tunnel, as if they were connected using the
same LAN. Ethernet Virtual Network can serve scenarios such as
campus networks, enterprise branch interconnections, data center
networks, wide area IP bearer networks, and SD-WAN. There have been
multiple solutions, they may differ in the types of underlying
networks or encapsulation methods, besides, they usually serve
different scenarios.
VXLAN [RFC7348] is a network virtualization technology which has been
used mainly in data centers. VXLAN uses MAC-in-UDP encapsulation for
packets, specifically, it encapsulates original Ethernet frames into
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UDP packets. It then encapsulates the UDP packets with the IP header
and Ethernet header of the physical network as outer headers,
enabling these packets to be routed across the network like ordinary
IP packets.
VPLS [RFC4762] make use of MPLS and VPN protocols to provide a
virtual LAN between multiple locations. It is basically a way to
provide Ethernet-based multi-point to multi-point communication over
MPLS networks. VPLS operates by creating a virtual ‘switch’ at the
customer’s edge (CE) and the provider’s edge (PE) of their respective
networks.
The new approach, namely EVN6, proposed in this document aims to
efficiently carry Ethernet Virtual Networks in IPv6 networks. It
provides a methodology for dynamically creating a tunnel on the IPv6
network to transparently forward Ethernet frame when communication is
required between a source and destination node in a Ethernet Virtual
Network. In this scheme, Ethernet frame to be transmitted is
directly placed in the payload field of IPv6 packet without adding
additional payload, the MAC address of the hosts that needs to
communicate, the identification of the Ethernet Virtual Network and
the IPv6 prefix of the site can be used to generate outer IPv6
addresses. With EVN6 implementation, any two host can communicate,
regardless of the underlying IPv6 network structure and other
details. This document specifies EVN6’s overall architecture,
typical workflow, Layer-2 multicast and broadcast processing, etc.
1.1. 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.
2. Terminology
The following terms are defined and used in this document,
EVN6: Multi-site Ethernet Virtual Network built on IPv6 network
E-ADPT: Ethernet Adaptor
IID: Interface Identifier(Section 2.5.1 of [RFC4291])
VEI: Virtual Ethernet Identification, VEI is used to identify and
distinguish different Ethernet Virtual Network instances across
the entire network, the length of VEI is 32 bits
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MAC-VRF: A Virtual Routing and Forwarding table for Media Access
Control (MAC) addresses on a PE（Section 3 of [RFC8365]）, it
stores IPv6 site prefix, VEI of the Ethernet Virtual Network and
other information of each MAC address
PE: Provider Edge Router
Pref6: Site prefix, Pref6 is a 64 bits subnet prefix (Section 2.5
of [RFC4291]) to identify one site of a given EVN6 instance
3. Overall Architecture
As a common underlay infrastructure, IPv6 network should
simultaneously support multiple Ethernet Virtual Networks. To
distinguish different Ethernet Virtual Network instances, VEI with a
length of 32-bits is used to globally identify them, and it can
identify up to 4.29 billion Ethernet Virtual Networks.
Generally, Ethernet Virtual Network consists of multiple sites
distributed in different geographically locations, and each site is
connected to the IPv6 network through local PE at the edge of the
IPv6 network. The PE device supports Ethernet Virtual Network
services by introducing E-ADPT functional subsystem. E-ADPT directly
encapsulates the Ethernet data frames to be transmitted by the
customer site into IPv6 packets and sends them to the IPv6 network.
For the received IPv6 packets destined to one of this local sites,
E-ADPT removes their packet header and restores the original Ethernet
frames.
--------------- ---------
+---+ Pref6-1 | +----+-----+ | | | Pref6-2 +---+
| H1+---------+--+ E-ADPT | | | +---------+ H2|
+---+ Site1 | +----------+ | | | Site2 +---+
| | | | | |
| | +-------+ | | |
| | |MAC-VRF| | | |
| | +-------+ | | |
|+-------------+| ----------- | |
||IPv6 Network || / \ | |
|| Layer |--|IPv6 Network |--| |
|+-------------+| \ / | |
--------------- ----------- ---------
PE1 PE2
Figure 1: EVN6 System Architecture
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For a given Ethernet Virtual Network, E-ADPT uses the IPv6 site
prefix, i.e., Pref6, to identify different sites, so the Pref6 of
different sites within a given Ethernet Virtual Network is also
different. There are no special requirements for the type of address
block used for Pref6, as long as it belongs to the global unicast
address type and is reachable in global routing system. The Pref6
for each site can be allocated from the IPv6 address space owned by
the operator. It should be noted that the length of Pref6 can be
flexibly selected, it can be equal to or less than 64 bits. For
Ethernet Virtual Network which has multiple sites, there is a 1: N
relationship between the VEI and the site prefix of its sites.
In order to send Ethernet frames to the correct destination site
through the IPv6 network, MAC-VRF table in PE is used to store the
MAC addresses of all hosts in the Ethernet Virtual Network, the
corresponding VEI of the Ethernet Virtual Network and Pref6 of the
sites they belong to. The format of each record in MAC-VRF is shown
in figure 2, it contains MAC address, VEI, prefix of the
corresponding site, Group Policy ID and Host ID.
+----------------------------------------------------------------+
| MAC Address | VEI | Pref6 | Group Policy ID | Host ID |
+----------------------------------------------------------------+
Pref6:Site Prefix
Figure 2: Structure of the Record in MAC-VRF
Group Policy ID: 24-bits identifier that indicates the source TSI
Group membership being encapsulated by EVN6. The allocation of Group
Policy ID values is outside the scope of this document.
Host ID: 20-bits identifier that indicates the membership of each
host within the site it belongs to, the Host ID of each host is
allocated from the Host ID Pool based on the host's MAC address while
ensuring its local uniqueness.
For E-ADPT, MAC-VRF provides a data foundation for encapsulating
Ethernet frames into corresponding IPv6 packets, the data in it
should be available before sending Ethernet frame to other sites, so
the mechanism requires the sites to pre-send host MAC/Pref6 Mapping
Advertisement to other sites. After receiving mapping relationship
data of a host sent by other PEs, the PE stores the mapping data in
the local MAC-VRF. The exchange of MAC/Pref6 can be carried out
through the control layer, such as extending EVPN[RFC7432], however,
this has been out of the scope of this document and will be discussed
in other documents. When receiving Ethernet frame data sent by the
host within the site, PE uses the destination MAC address as an index
to search for the local MAC-VRF table. If a corresponding entry is
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found, PE extracts its site prefix Pref6 and VEI value, then uses the
process in section 4.2 to encapsulate the Ethernet frame in an IPv6
packet. Afterwards, the IPv6 data packet is transmitted to the IPv6
network.
4. Operation
In this section, the Ethernet Virtual Network in figure 3 is used as
an example to illustrate the workflow, its profile includes: the VEI
value is N1, it has three branch sites connected to PE1, PE2, and
PE3, with site prefixes Pref6-1, Pref6-2, and Pref6-3, respectively.
Hosts H1, H2, H3 and H4 are located at sites 1, site 2 and site 3,
respectively.
+-------------------+
| |
| +--+--+ +----+
+---+ +--+--+ | | Site2(Pref6-2) | |
| |Site1(Pref6-1)| | | PE2 +-------------------+ H2 |MAC2
| H1+--------------+ PE1 | | | | |
| | | | +--+--+ +----+
+---+ +--+--+ | +----+
MAC1 | IPv6 | | |
| network | ----+ H3 |MAC3
| +--+--+ | | |
| | |Site3(Pref6-3)| +----+
| | PE3 +--------------|
| | | | +----+
| +--+--+ | | |
| | ----+ H4 |MAC4
+-------------------+ | |
+----+
Figure 3: Diagram of Typical EVN6 Instance
The workflow of EVN6 is illustrated as follows:
4.1. Network Creation Procedures
Step 1: EVN6 network creation on each PE device
When creating an Ethernet Virtual Network instance on an IPv6
network, it should firstly enable the EVN6 function is in PE1, PE2,
and PE3, then configure the relevant information of the Ethernet
Virtual Network on this site, configure the Ethernet Virtual Network
identifier VEI as N1, and set the site prefix Pref6 on the interface
of the PE that the site accesses, indicating that the VEI of the
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Ethernet Virtual Network to which the site belongs to is N1, and its
local site prefix is Pref6. This process can be configured manually
or using specific systems such as network management. When the EVN6
instance is running, the sites within it exchange host MAC/Pref6
Mapping through the connected PEs, as described in Section 3.
4.2. Data Transmission Procedures
Step 2: Host information searching
Host H2 in site 2 sends an Ethernet frame with the destination being
Host H1 in site 1. Its frame header contains the MAC source address
and MAC destination address, which are the MAC addresses of hosts H2
and H1, respectively. In this case, PE2 is the source PE and PE1 is
the destination PE. After receiving the Ethernet frame in Site 2,
PE2 uses the destination MAC address as an index to search for the
local MAC-VRF table. If a corresponding entry is found, the Pref6 of
remote site (i.e. Pref6-1) and VEI information are extracted; If not
found, do not encapsulate and forward.
Step 3: Address mapping and frame encapsulation
In EVN6, each Ethernet frame needs to be associated with the VEI of
the Ethernet Virtual Network to which the frame originates. Upon
receiving the Ethernet frame, PE2 can determine its VEI value based
on local configuration. Then the VEI obtained is divided into two
sub-segments: VEI-S1 and VEI-S2, the first 16 bits are VEI-S1, and
the last 16 bits are VEI-S2. VEI-S1 and VEI-S2 will be respectively
put into IPv6 source and destination address of the new IPv6 packet.
IPv6 source and destination addresses are generated statelessly and
their formats are shown in figure 4.
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IPv6 Source Address
0 64 80 84 108 128
+---------------------+--------+----+----------+--------+
| Pref6 of | VEI-S1 |Flag| Ext. | Source |
| Source Site | | | Bits | Host ID|
+---------------------+--------+----+----------+--------+
|<--------------IID-------------->|
IPv6 Destination Address
0 64 80 84 108 128
+---------------------+--------+----+----------+--------+
| Pref6 of | VEI-S2 |Flag| Ext. | Dst. |
| Destination Site | | | Bits | Host ID|
+---------------------+--------+----+----------+--------+
|<--------------IID-------------->|
Figure 4: Formats of IPv6 Source and Destination Addresses
Each field of the IPv6 source address is illustrated as follows,
-Pref6 of Source Site: 64-bits in length with the value of
Pref6-2, it is for identifying the site that the source host
belongs to.
-VEI-S1: 16-bits in length, it starts from the 64th bit of source
IPv6 address.
-Flag: 4-bits in length, it is a identification field in the
format of GRRR. The first bit, i.e., G bit, is the Group Policy
flag, and the last three digits are reserved bits, with a default
value of 0. If the G bit is 1, the 24-bits Extensible Bits field
is assigned to the Group Policy ID; If the G flag is 0, then all
the 24 bits are set to zero.
-Extensible Bits: 24-bits in length, its value is related to the
Flag field as mentioned above.
-Source Host ID: 20-bits in length, it is for identifying the
site to which the source host belongs. The local site PE
allocates the host ID from the Host ID Pool based on the host's
MAC address. Host ID is stored at the MAC-VRF table of local
site.
Each field of IPv6 destination address is illustrated as follows,
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-Pref6 of Destination Site: 64-bits in length with the value of
Pref6-1, it is for identifying the site that the destination host
belongs to.
-VEI-S2: 16-bits in length, it starts from the 64th bit of
destination IPv6 address.
-Flag: 4-bits in length, it is a identification field in the
format of GRRR. The first bit, i.e., G bit, is the Group Policy
flag, and the last three digits are reserved bits, with a default
value of 0. If the G bit is 1, the 24-bits Extensible Bits field
is assigned to the Group Policy ID; If the G flag is 0, then all
the 24 bits are set to zero.
-Extensible Bits: 24-bits in length, its value is related to the
Flag field as mentioned above.
-Destination Host ID: 20-bits in length, it is for identifying
the site to which the destination host belongs. If the frame is
an unicast message, the Host ID is allocated from the host ID
Pool of the destination site, and stored in the MAC-VRF of
destination site; If it is a BUM message, the Host ID in the
destination address is set to FFFFF.
Moreover, the Ethernet frame is put into the payload of IPv6 packet
and the value of the "Next header" in the header is set to 143,
indicating that the payload of the IPv6 packet is an Ethernet frame.
+-------------------------------+
| Ethernet Frame |
+-------------------------------+
|
V
+-----------------+-------------------------------+
| IPv6 Header | Payload(Ethernet Frame) |
+-----------------+-------------------------------+
Figure 5: Encapsulation of Ethernet Frame into IPv6 Packet
After the IPv6 packet is generated, it is sent to the IPv6 network
via the underlying IPv6 network layer.
Step 4: Packet forwarding in IPv6 network
When receiving an IPv6 packet, routers in an IPv6 network use the
destination address in the packet to look up the routing table and
forward it. Since the IPv6 destination address contains the site
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prefix of the destination site, i.e. Pref6-1 in this case, which
provides the egress PE of the packet, routers can forward the IPv6
packet carrying the Ethernet frame to the destination PE, i.e. PE1 in
this case. It should be noted that this process does not require
additional functionality for non-PE routers in the network, nor does
it require extra IPv6 routing information to be added to the IPv6
network.
4.3. Data Receiving Procedures
Step 5: Packet de-capsulation and Ethernet frame restoration
As shown in figure 6, when receiving a IPv6 packet, the receiving PE,
i.e., PE1, checks whether the destination address prefix matches the
site prefix Pref6-1 on PE1? If yes, it extracts VEI-S1 and VEI-S2
from the IIDs of the source and destination IPv6 addresses, and
concatenates them into VEI, then check if the VEI value is equal to
N1? If yes, it then checks if the "Next header" value in the IPv6
header is 143? If yes, it then discards the IPv6 header, takes out
the Ethernet frame, and sends the Ethernet frame to H1 within Site 1
based on its destination MAC address. Otherwise, the packet is
discarded due to abnormal situation.
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+---------------------------+
|PE1 receives an IPv6 packet|
+---------------------------+
|
V
+------+
/Does the \
N '/destination\
--------------------+ address +
| \ match /
V \ Pref6-1 /
+------------------------+ +------+
|PE1 continues forwarding| Y|
|forwarding IPv6 packet | V
+------------------------+ +-------------------------+
|PE1 extracts VEI from the|
|IIDs of IPv6 source and |
|destination addresses |
+-------------------------+
|
V
+--+
N / \
----------------------+ VEI=N1?+
| \ /
V +--+
+----------------------------+ Y|
|The packet is discarded due | |
|to abnormal situation | V
+----------------------------+ +-----+
/ The \
N / value of \
-------------------+"Next header"+
| \ is 143? /
V \ /
+----------------------------+ +-----+
|The packet is discarded due | Y|
|to abnormal situation | |
+----------------------------+ V
+------------------------------------------+
|PE1 decapsulates IPv6 packet and sends the|
| released Ethernet frame to H1 based on |
| the destination MAC address |
+------------------------------------------+
Figure 6: Process of Ethernet Frame Restoration in PE
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5. Multicast and Broadcast
5.1. Multicast
Link layer multicast is used to send Ethernet frames to multiple
members of a group, these members are distributed on different sites
of the Ethernet virtual network. The case here is used to illustrate
multicast process: VN1 is an instance of Ethernet virtual network
over IPv6 underlay, it consists of N1 sites, contains M1 hosts
distributed on different sites, and its VEI is vn1. Of all the
sites, site-0 has the site prefix Pref6-0 and is connected to the
local PE1.
G1 is a multicast group in instance VN1, it contains m1 members, and
m1 is less or equal than M1. The members of G1 are distributed on n1
sites of instance VN1: site-1, site-2, …, Site-n1, since these sites
are partial of the total site set, n1 is less or equal than N1. The
site prefixes of each site are Pref6-1, Pref6-2, … , Pref6-n1. For
multicast, MAC-VRF also maintains related entries, with MAC addresses
being multicast addresses. Per IEEE 802.1Q, multicast addresses of
Ethernet have the least significant bit in the first octet set to 1.
Due to the presence of multiple destination sites for a given group,
there are multiple site prefixes in each entry as follows:
+--------------------------------------------------------------------------+
| Multicast MAC Address | VEI |Length of Pref6|Pref6-1,Pref6-2,...,Pref6-n1|
+--------------------------------------------------------------------------+
Figure 7: Record of Multicast in MAC-VRF
Host H1 in site-0 sends a multicast frame to group G1. When the
E-ADPT in PE1 receives the frame, it will lookup its MAC-VRF with the
destination multicast address of the frame as the key. When a
matching entry is found and its VEI field is vn1, the list of site
prefix is extracted from the entry. Each item in the list is the
site prefix of the remote site where the members of group G1 are
located on. Then, for each remote site, the following operations are
performed recurrently by the E-ADPT of PE1,
{
- Generate the source IPv6 address with the source MAC address,
vn1 and Pref6-0 using the method in section 4.2.
- Generate the source IPv6 address with destination multicast MAC
address, vn1 and Pref6-k using the method in section 4.2.
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- Generate the IPv6 header using the IPv6 source and destination
addresses created above, encapsulate the frame into IPv6 packet,
then send the new IPv6 packet into the IPv6-only network.
}
Through the above n1 cycles the multicast frame is encapsulated into
IPv6 packet and send the data out.
When the packet traverses the IPv6-only network and reaches an egress
PE, for instance, PE2. The E-ADPT of PE2 extracts its destination
site prefix, i.e. Pref6-k, and VEI with value of vn1 from its IPv6
destination and source addresses. E-ADPT uses Pref6-k as the key to
query the local MAC-VRF. If the corresponding entry is found, and
the value of the VEI field is vn1, this indicates that one site
attached to PE2 hosts the members of group G1, then, E-ADPT removes
the IPv6 header and sends the released frame with the original
multicast MAC address into this site.
5.2. Broadcast
Link layer broadcast is used to send Ethernet frames to any other
hosts of the virtual Ethernet instance. Per 802.1Q, the destination
address of the broadcast frame is FF-FF-FF-FF-FF-FF, and all hosts in
the same Layer-2 network will receive the broadcast frame. EVN6
framework needs to support link layer broadcast as well. Herein, the
case of instance VN1 in section 5.1 is used to illustrate the process
of broadcast.
Host H1 located in site-0 sends a broadcast Ethernet frame. After
receiving the frame and detecting that the destination MAC address is
a broadcast address, PE1 needs to transmit it to each remote site of
instance VN1. The E-ADPT in PE1 queries the MAC-VRF with the value
of vn1 as the key, retrieves all the site prefixes of instance VN1:
Pref6-1, Pref6-2, … , Pref6-N1. Then, for each remote site, the
following operations are performed recurrently by the E-ADPT of PE1,
{
- Generate the source IPv6 address with the source MAC address,
vn1 and Pref6-0 of site-0 using the method in section 4.2.
- Generate the source IPv6 address with the broadcast MAC
address(ff:ff:ff:ff:ff:ff), Pref6-k and vn1 using the method in
section 4.2.
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- Generate the IPv6 header using the IPv6 source and destination
addresses created above, encapsulate the frame into IPv6 packet,
then send the new IPv6 packet into the IPv6-only network.
}
Through the above N1-1 cycles the broadcast frame is encapsulated
into IPv6 packets and send the data out.
When the packet traverses the IPv6-only network and reaches an egress
PE, for instance, PE2. The E-ADPT of PE2 extracts its Pref6-k and
VEI with the value of vn1 from the destination IPv6 address and
source IPv6 address of the packet. E-ADPT uses Pref6-k as the key to
query the local MAC-VRF. If the corresponding entry is found and its
VEI value is also vn1, this indicates that the site on PE2 is one
site of instance VN1, then, E-ADPT remove the IPv6 header sends the
broadcast frame to this site.
6. Security Considerations
In the EVN6 framework, PE devices located at the edge of the network
encapsulate Ethernet frames in IPv6 packets and support transmission
between different sites. When generating the outer IPv6 header, the
PE device maps information such as the IPv6 address prefix of the
site, the Mac address of the host, and the identity of the virtual
network to the IPv6 address of the outer encapsulation header, which
applies to both the source and destination addresses. In this way,
the outer IPv6 address is dynamically generated based on information
such as MAC address. For any host to host communication, even if the
source and destination hosts are in the same virtual private network,
when their source and destination address pairs are different, the
generated outer encapsulated IP address is also different. The outer
IPv6 address varies with the MAC address of the Ethernet frame, this
is different from the traditional encapsulation scheme of pre-
configuring tunnel IP addresses, as statically configured tunnel
endpoint addresses are likely to become the target of DDOS attacks.
In EVN6, tunnel encapsulation adopts dynamically generated tunnel
endpoint IPv6 addresses, which avoids the occurrence of DDOS attacks
caused by statically pre-configured tunnel addresses. From this
perspective, this solution improves the security of Ethernet virtual
networks.
7. Benefits and Advantages Analysis
Compared with existing overlay approaches, EVN6 is perceived to have
the following major advantages,
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1)Improved forwarding efficiency
EVN6 encapsulates Ethernet frame into IPv6 packet without extra
encapsulation headers, compared with existing approaches, such as
VxLAN, encapsulation and processing cost can be reduced.
2) High delivery flexibility
EVN6 service can be provisioned to customer site as long as its
access to lPv6 Internet is available. There is no specific
requirement for the interworking between ISPs, so it can be easily
deployed in multi-operator environment.
3)Enhanced anti-DDoS capability
With EVN6 tunnel endpoint addresses are generated dynamically and
there is no pre-configured static tunnel endpoint address, so the
risk of DDoS attack to pre-configured static address can be avoided.
4)Source address based Traffic load-balancing
Since the outer IPv6 source and destination addresses are generated
by mapping source and destination host MAC address, VEI and site
prefixes, different hosts within the same site have different outer
IPv6 addresses, so traffic load balancing can be implemented based on
the source IPv6 addresses.
8. IANA Considerations
There are no other special IANA considerations.
9. Acknowledgment
10. References
10.1. Normative References
[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>.
[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>.
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[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>.
[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>.
10.2. Informative References
[IEEE.802.1D.2004]
"IEEE Standard for Information technology—
Telecommunications and information exchange between
systems— Local and metropolitan area networks— Specific
requirements Part 11: Wireless LAN Medium Access Control
(MAC) and Physical Layer (PHY) Specifications", March
2012, <http://standards.ieee.org/getieee802/
download/802.1D-2004.pdf>.
[IEEE.802.1Q.2014]
"IEEE Standard for Information technology—
Telecommunications and information exchange between
systems— Local and metropolitan area networks— Specific
requirements Part 11: Wireless LAN Medium Access Control
(MAC) and Physical Layer (PHY) Specifications", March
2012, <http://standards.ieee.org/getieee802/
download/802.1Q-2014.pdf>.
[RFC4762] Lasserre, M., Ed. and V. Kompella, Ed., "Virtual Private
LAN Service (VPLS) Using Label Distribution Protocol (LDP)
Signaling", RFC 4762, DOI 10.17487/RFC4762, January 2007,
<https://www.rfc-editor.org/info/rfc4762>.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
DOI 10.17487/RFC4861, September 2007,
<https://www.rfc-editor.org/info/rfc4861>.
[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>.
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[RFC7364] Narten, T., Ed., Gray, E., Ed., Black, D., Fang, L.,
Kreeger, L., and M. Napierala, "Problem Statement:
Overlays for Network Virtualization", RFC 7364,
DOI 10.17487/RFC7364, October 2014,
<https://www.rfc-editor.org/info/rfc7364>.
[RFC7365] Lasserre, M., Balus, F., Morin, T., Bitar, N., and Y.
Rekhter, "Framework for Data Center (DC) Network
Virtualization", RFC 7365, DOI 10.17487/RFC7365, October
2014, <https://www.rfc-editor.org/info/rfc7365>.
[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>.
[RFC8926] Gross, J., Ed., Ganga, I., Ed., and T. Sridhar, Ed.,
"Geneve: Generic Network Virtualization Encapsulation",
RFC 8926, DOI 10.17487/RFC8926, November 2020,
<https://www.rfc-editor.org/info/rfc8926>.
Authors' Addresses
Chongfeng Xie
China Telecom
Beiqijia Town, Changping District
Beijing
102209
China
Email: xiechf@chinatelecom.cn
Jibin Sun
China Telecom
Beiqijia Town, Changping District
Beijing
102209
China
Email: sunjb@chinatelecom.cn
Xing Li
CERNET Center/Tsinghua University
Shuangqing Road No.30, Haidian District
Beijing
100084
China
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Email: xing@cernet.edu.cn
Congxiao Bao
CERNET Center/Tsinghua University
Shuangqing Road No.30, Haidian District
Beijing
100084
China
Email: congxiao@cernet.edu.cn
Mark Smith
PO BOX 521
Heidelberg 3084
Australia
Email: markzzzsmith@gmail.com
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