Internet DRAFT - draft-xu-l3vpn-virtual-subnet
draft-xu-l3vpn-virtual-subnet
Network working group X. Xu
Internet Draft Huawei
Category: Informational
R. Raszuk
S. Hares
Y. Fan
China Telecom
C. Jacquenet
Orange
T. Boyes
Bloomberg LP
B Fee
Extreme Networks
Expires: July 2014 January 18, 2014
Virtual Subnet: A L3VPN-based Subnet Extension Solution
draft-xu-l3vpn-virtual-subnet-03
Abstract
This document describes a Layer3 Virtual Private Network (L3VPN)-
based subnet extension solution referred to as Virtual Subnet, which
can be used as a kind of Layer3 network virtualization overlay
approach for data center interconnect.
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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and may be updated, replaced, or obsoleted by other documents at any
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described in the Simplified BSD License.
Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC-2119 [RFC2119].
Table of Contents
1. Introduction ................................................ 4
2. Terminology ................................................. 6
3. Solution Description......................................... 6
3.1. Unicast ................................................ 6
3.1.1. Intra-subnet Unicast .............................. 6
3.1.2. Inter-subnet Unicast .............................. 7
3.2. Multicast .............................................. 9
3.3. CE Host Discovery ..................................... 10
3.4. ARP/ND Proxy .......................................... 10
3.5. CE Host Mobility ...................................... 10
3.6. Forwarding Table Scalability on Data Center Switches .. 11
3.7. ARP/ND Cache Table Scalability on Default Gateways .... 11
3.8. ARP/ND and Unknown Uncast Flood Avoidance ............. 11
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3.9. Path Optimization ..................................... 11
4. Limitations ................................................ 12
4.1. Non-support of Non-IP Traffic ......................... 12
4.2. Non-support of IP Broadcast and Link-local Multicast .. 12
4.3. TTL and Traceroute .................................... 13
5. Security Considerations .................................... 13
6. IANA Considerations ........................................ 13
7. Acknowledgements ........................................... 13
8. References ................................................. 13
8.1. Normative References .................................. 13
8.2. Informative References ................................ 14
Authors' Addresses ............................................ 14
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1. Introduction
For business continuity purposes, Virtual Machine (VM) migration
across data centers is commonly used in those situations such as data
center maintenance, data center migration, data center consolidation,
data center expansion, and data center disaster avoidance. It's
generally admitted that IP renumbering of servers (i.e., VMs) after
the migration is usually complex and costly at the risk of extending
the business downtime during the process of migration. To allow the
migration of a VM from one data center to another without IP
renumbering, the subnet on which the VM resides needs to be extended
across these data centers.
In Infrastructure-as-a-Service (IaaS) cloud data center environments,
to achieve subnet extension across multiple data centers in a
scalable way, the following requirements SHOULD be considered for any
data center interconnect solution:
1) VPN Instance Space Scalability
In a modern cloud data center environment, thousands or even tens
of thousands of tenants could be hosted over a shared network
infrastructure. For security and performance isolation purposes,
these tenants need to be isolated from one another. Hence, the
data center interconnect solution SHOULD be capable of providing a
large enough Virtual Private Network (VPN) instance space for
tenant isolation.
2) Forwarding Table Scalability
With the development of server virtualization technologies, a
single cloud data center containing millions of VMs is not
uncommon. This number already implies a big challenge for data
center switches, especially for core/aggregation switches, from
the perspective of forwarding table scalability. Provided that
multiple data centers of such scale were interconnected at layer2,
this challenge would be even worse. Hence an ideal data center
interconnect solution SHOULD prevent the forwarding table size of
data center switches from growing by folds as the number of data
centers to be interconnected increases.
3) ARP/ND Cache Table Scalability on Default Gateways
[RFC6820] notes that the Address Resolution Protocol
(ARP)/Neighbor Discovery (ND) cache tables maintained by data
center default gateways in cloud data centers can raise both
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scalability and security issues. Therefore, an ideal data center
interconnect solution SHOULD prevent the ARP/ND cache table size
from growing by multiples as the number of data centers to be
connected increases.
4) ARP/ND and Unknown Unicast Flood Suppression or Avoidance
It's well-known that the flooding of Address Resolution Protocol
(ARP)/Neighbor Discovery (ND) broadcast/multicast and unknown
unicast traffic within a large Layer2 network are likely to affect
performances of networks and hosts. As multiple data centers each
containing millions of VMs are interconnected together across the
Wide Area Network (WAN) at layer2, the impact of flooding as
mentioned above will become even worse. As such, it becomes
increasingly desirable for data center operators to suppress or
even avoid the flooding of ARP/ND broadcast/multicast and unknown
unicast traffic across data centers.
5) Path Optimization
A subnet usually indicates a location in the network. However,
when a subnet has been extended across multiple geographically
dispersed data center locations, the location semantics of such
subnet is not retained any longer. As a result, the traffic from a
cloud user (i.e., a VPN user) which is destined for a given server
located at one data center location of such extended subnet may
arrive at another data center location firstly according to the
subnet route, and then be forwarded to the location where the
service is actually located. This suboptimal routing would
obviously result in the unnecessary consumption of the bandwidth
resources which are intended for data center interconnection.
Furthermore, in the case where the traditional VPLS technology
[RFC4761, RFC4762] is used for data center interconnect and
default gateways of different data center locations are configured
within the same virtual router redundancy group, the returning
traffic from that server to the cloud user may be forwarded at
layer2 to a default gateway located at one of the remote data
center premises, rather than the one placed at the local data
center location. This suboptimal routing would also unnecessarily
consume the bandwidth resources which are intended for data center
interconnect.
This document describes a L3VPN-based subnet extension solution
referred to as Virtual Subnet (VS), which can meet all of the
requirements of cloud data center interconnect as described above.
Since VS mainly reuses existing technologies including BGP/MPLS IP
VPN [RFC4364] and ARP/ND proxy [RFC925][RFC1027][RFC4389], it allows
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those service providers offering IaaS public cloud services to
interconnect their geographically dispersed data centers in a much
scalable way, and more importantly, data center interconnection
design can rely upon their existing MPLS/BGP IP VPN infrastructures
and their experiences in the delivery and the operation of MPLS/BGP
IP VPN services.
Although Virtual Subnet is described as a data center interconnection
solution in this document, there is no reason to assume that this
technology couldn't be used within data centers.
Note that the approach described in this document is not intended to
achieve an exact emulation of L2 connectivity and therefore can only
support a restricted L2 connectivity service model with limitations
declared in Section 4. As for the discussion about in which
environment this service model should be suitable, it's outside the
scope of this document.
2. Terminology
This memo makes use of the terms defined in [RFC4364].
3. Solution Description
3.1. Unicast
3.1.1. Intra-subnet Unicast
+--------------------+
+-----------------+ | | +-----------------+
|VPN_A:1.1.1.1/24 | | | |VPN_A:1.1.1.1/24 |
| \ | | | | / |
| +------+ \++---+-+ +-+---++/ +------+ |
| |Host A+----+ PE-1 | | PE-2 +----+Host B| |
| +------+\ ++-+-+-+ +-+-+-++ /+------+ |
| 1.1.1.2/24 | | | | | | 1.1.1.3/24 |
| | | | | | | |
| DC West | | | IP/MPLS Backbone | | | DC East |
+-----------------+ | | | | +-----------------+
| +--------------------+ |
| |
VRF_A : V VRF_A : V
+------------+---------+--------+ +------------+---------+--------+
| Prefix | Nexthop |Protocol| | Prefix | Nexthop |Protocol|
+------------+---------+--------+ +------------+---------+--------+
| 1.1.1.1/32 |127.0.0.1| Direct | | 1.1.1.1/32 |127.0.0.1| Direct |
+------------+---------+--------+ +------------+---------+--------+
| 1.1.1.2/32 | 1.1.1.2 | Direct | | 1.1.1.2/32 | PE-1 | IBGP |
+------------+---------+--------+ +------------+---------+--------+
| 1.1.1.3/32 | PE-2 | IBGP | | 1.1.1.3/32 | 1.1.1.3 | Direct |
+------------+---------+--------+ +------------+---------+--------+
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| 1.1.1.0/24 | 1.1.1.1 | Direct | | 1.1.1.0/24 | 1.1.1.1 | Direct |
+------------+---------+--------+ +------------+---------+--------+
Figure 1: Intra-subnet Unicast Example
As shown in Figure 1, two CE hosts (i.e., Hosts A and B) belonging to
the same subnet (i.e., 1.1.1.0/24) are located at different data
centers (i.e., DC West and DC East) respectively. PE routers (i.e.,
PE-1 and PE-2) which are used for interconnecting these two data
centers create host routes for their local CE hosts respectively and
then advertise them via L3VPN signaling. Meanwhile, ARP proxy is
enabled on VRF attachment circuits of these PE routers.
Now assume host A sends an ARP request for host B before
communicating with host B. Upon receiving the ARP request, PE-1
acting as an ARP proxy returns its own MAC address as a response.
Host A then sends IP packets for host B to PE-1. PE-1 tunnels such
packets towards PE-2 which in turn forwards them to host B. Thus,
hosts A and B can communicate with each other as if they were located
within the same subnet.
3.1.2. Inter-subnet Unicast
+--------------------+
+-----------------+ | | +-----------------+
|VPN_A:1.1.1.1/24 | | | |VPN_A:1.1.1.1/24 |
| \ | | | | / |
| +------+ \++---+-+ +-+---++/ +------+ |
| |Host A+------+ PE-1 | | PE-2 +-+----+Host B| |
| +------+\ ++-+-+-+ +-+-+-++ | /+------+ |
| 1.1.1.2/24 | | | | | | | 1.1.1.3/24 |
| GW=1.1.1.4 | | | | | | | GW=1.1.1.4 |
| | | | | | | | +------+ |
| | | | | | | +----+ GW +--|
| | | | | | | /+------+ |
| | | | | | | 1.1.1.4/24 |
| | | | | | | |
| DC West | | | IP/MPLS Backbone | | | DC East |
+-----------------+ | | | | +-----------------+
| +--------------------+ |
| |
VRF_A : V VRF_A : V
+------------+---------+--------+ +------------+---------+--------+
| Prefix | Nexthop |Protocol| | Prefix | Nexthop |Protocol|
+------------+---------+--------+ +------------+---------+--------+
| 1.1.1.1/32 |127.0.0.1| Direct | | 1.1.1.1/32 |127.0.0.1| Direct |
+------------+---------+--------+ +------------+---------+--------+
| 1.1.1.2/32 | 1.1.1.2 | Direct | | 1.1.1.2/32 | PE-1 | IBGP |
+------------+---------+--------+ +------------+---------+--------+
| 1.1.1.3/32 | PE-2 | IBGP | | 1.1.1.3/32 | 1.1.1.3 | Direct |
+------------+---------+--------+ +------------+---------+--------+
| 1.1.1.4/32 | PE-2 | IBGP | | 1.1.1.4/32 | 1.1.1.4 | Direct |
+------------+---------+--------+ +------------+---------+--------+
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| 1.1.1.0/24 | 1.1.1.1 | Direct | | 1.1.1.0/24 | 1.1.1.1 | Direct |
+------------+---------+--------+ +------------+---------+--------+
| 0.0.0.0/0 | PE-2 | IBGP | | 0.0.0.0/0 | 1.1.1.4 | Static |
+------------+---------+--------+ +------------+---------+--------+
Figure 2: Inter-subnet Unicast Example (1)
As shown in Figure 2, only one data center (i.e., DC East) is
deployed with a default gateway (i.e., GW). PE-2 which is connected
to GW would either be configured with or learn from GW a default
route with next-hop being pointed to GW. Meanwhile, this route is
distributed to other PE routers (i.e., PE-1) as per normal [RFC4364]
operation. Assume host A sends an ARP request for its default
gateway (i.e., 1.1.1.4) prior to communicating with a destination
host outside of its subnet. Upon receiving this ARP request, PE-1
acting as an ARP proxy returns its own MAC address as a response.
Host A then sends a packet for Host B to PE-1. PE-1 tunnels such
packet towards PE-2 according to the default route learnt from PE-2,
which in turn forwards that packet to GW.
+--------------------+
+-----------------+ | | +-----------------+
|VPN_A:1.1.1.1/24 | | | |VPN_A:1.1.1.1/24 |
| \ | | | | / |
| +------+ \++---+-+ +-+---++/ +------+ |
| |Host A+----+-+ PE-1 | | PE-2 +-+----+Host B| |
| +------+\ | ++-+-+-+ +-+-+-++ | /+------+ |
| 1.1.1.2/24 | | | | | | | | 1.1.1.3/24 |
| GW=1.1.1.4 | | | | | | | | GW=1.1.1.4 |
| +------+ | | | | | | | | +------+ |
|--+ GW-1 +----+ | | | | | | +----+ GW-2 +--|
| +------+\ | | | | | | /+------+ |
| 1.1.1.4/24 | | | | | | 1.1.1.4/24 |
| | | | | | | |
| DC West | | | IP/MPLS Backbone | | | DC East |
+-----------------+ | | | | +-----------------+
| +--------------------+ |
| |
VRF_A : V VRF_A : V
+------------+---------+--------+ +------------+---------+--------+
| Prefix | Nexthop |Protocol| | Prefix | Nexthop |Protocol|
+------------+---------+--------+ +------------+---------+--------+
| 1.1.1.1/32 |127.0.0.1| Direct | | 1.1.1.1/32 |127.0.0.1| Direct |
+------------+---------+--------+ +------------+---------+--------+
| 1.1.1.2/32 | 1.1.1.2 | Direct | | 1.1.1.2/32 | PE-1 | IBGP |
+------------+---------+--------+ +------------+---------+--------+
| 1.1.1.3/32 | PE-2 | IBGP | | 1.1.1.3/32 | 1.1.1.3 | Direct |
+------------+---------+--------+ +------------+---------+--------+
| 1.1.1.4/32 | 1.1.1.4 | Direct | | 1.1.1.4/32 | 1.1.1.4 | Direct |
+------------+---------+--------+ +------------+---------+--------+
| 1.1.1.0/24 | 1.1.1.1 | Direct | | 1.1.1.0/24 | 1.1.1.1 | Direct |
+------------+---------+--------+ +------------+---------+--------+
| 0.0.0.0/0 | 1.1.1.4 | Static | | 0.0.0.0/0 | 1.1.1.4 | Static |
+------------+---------+--------+ +------------+---------+--------+
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Figure 3: Inter-subnet Unicast Example (2)
As shown in Figure 3, in the case where each data center is deployed
with a default gateway, CE hosts will get ARP responses directly from
their local default gateways, rather than from their local PE routers
when sending ARP requests for their default gateways.
+------+
+------+ PE-3 +------+
+-----------------+ | +------+ | +-----------------+
|VPN_A:1.1.1.1/24 | | | |VPN_A:1.1.1.1/24 |
| \ | | | | / |
| +------+ \++---+-+ +-+---++/ +------+ |
| |Host A+------+ PE-1 | | PE-2 +------+Host B| |
| +------+\ ++-+-+-+ +-+-+-++ /+------+ |
| 1.1.1.2/24 | | | | | | 1.1.1.3/24 |
| GW=1.1.1.1 | | | | | | GW=1.1.1.1 |
| | | | | | | |
| DC West | | | IP/MPLS Backbone | | | DC East |
+-----------------+ | | | | +-----------------+
| +--------------------+ |
| |
VRF_A : V VRF_A : V
+------------+---------+--------+ +------------+---------+--------+
| Prefix | Nexthop |Protocol| | Prefix | Nexthop |Protocol|
+------------+---------+--------+ +------------+---------+--------+
| 1.1.1.1/32 |127.0.0.1| Direct | | 1.1.1.1/32 |127.0.0.1| Direct |
+------------+---------+--------+ +------------+---------+--------+
| 1.1.1.2/32 | 1.1.1.2 | Direct | | 1.1.1.2/32 | PE-1 | IBGP |
+------------+---------+--------+ +------------+---------+--------+
| 1.1.1.3/32 | PE-2 | IBGP | | 1.1.1.3/32 | 1.1.1.3 | Direct |
+------------+---------+--------+ +------------+---------+--------+
| 1.1.1.0/24 | 1.1.1.1 | Direct | | 1.1.1.0/24 | 1.1.1.1 | Direct |
+------------+---------+--------+ +------------+---------+--------+
| 0.0.0.0/0 | PE-3 | IBGP | | 0.0.0.0/0 | PE-3 | IBGP |
+------------+---------+--------+ +------------+---------+--------+
Figure 4: Inter-subnet Unicast Example (3)
Alternatively, as shown in Figure 4, PE routers themselves could be
directly configured as default gateways of their locally connected CE
hosts as long as these PE routers have routes for outside networks.
3.2. Multicast
To support IP multicast between CE hosts of the same virtual subnet,
MVPN technology [MVPN] could be directly reused. For example, PE
routers attached to a given VPN join a default provider multicast
distribution tree which is dedicated for that VPN. Ingress PE routers,
upon receiving multicast packets from their local CE hosts, forward
them towards remote PE routers through the corresponding default
provider multicast distribution tree.
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More details about how to support multicast and broadcast in VS will
be explored in a later version of this document.
3.3. CE Host Discovery
PE routers SHOULD be able to discover their local CE hosts and keep
the list of these hosts up to date in a timely manner so as to ensure
the availability and accuracy of the corresponding host routes
originated from them. PE routers could accomplish local CE host
discovery by some traditional host discovery mechanisms using ARP or
ND protocols. Furthermore, Link Layer Discovery Protocol (LLDP)
described in [802.1AB] or VSI Discovery and Configuration Protocol
(VDP) described in [802.1Qbg], or even interaction with the data
center orchestration system could also be considered as a means to
dynamically discover local CE hosts.
3.4. ARP/ND Proxy
Acting as an ARP or ND proxies, a PE routers SHOULD only respond to
an ARP request or Neighbor Solicitation (NS) message for a target
host when it has a best route for that target host in the associated
VRF and the outgoing interface of that best route is different from
the one over which the ARP request or NS message is received.
In the scenario where a given VPN site (i.e., a data center) is
multi-homed to more than one PE router via an Ethernet switch or an
Ethernet network, Virtual Router Redundancy Protocol (VRRP) [RFC5798]
is usually enabled on these PE routers. In this case, only the PE
router being elected as the VRRP Master is allowed to perform the
ARP/ND proxy function.
3.5. CE Host Mobility
During the VM migration process, the PE router to which the moving VM
is now attached would create a host route for that CE host upon
receiving a notification message of VM attachment (e.g., a gratuitous
ARP or unsolicited NA message). The PE router to which the moving VM
was previously attached would withdraw the corresponding host route
when receiving a notification message of VM detachment (e.g., a VDP
message about VM detachment). Meanwhile, the latter PE router could
optionally broadcast a gratuitous ARP or send an unsolicited NA
message on behalf of that CE host with source MAC address being one
of its own. In this way, the ARP/ND entry of this CE host that moved
and which has been cached on any local CE host would be updated
accordingly. In the case where there is no explicit VM detachment
notification mechanism, the PE router could also use the following
trick to determine the VM detachment event: upon learning a route
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update for a local CE host from a remote PE router for the first time,
the PE router could immediately check whether that local CE host is
still attached to it by some means (e.g., ARP/ND PING and/or ICMP
PING).
It is important to ensure that the same MAC and IP are associated to
the default gateway active in each data center, as the VM would most
likely continue to send packets to the same default gateway address
after migrated from one data center to another. One possible way to
achieve this goal is to configure the same VRRP group on each
location so as to ensure the default gateway active in each data
center share the same virtual MAC and virtual IP addresses.
3.6. Forwarding Table Scalability on Data Center Switches
In a VS environment, the MAC learning domain associated with a given
virtual subnet which has been extended across multiple data centers
is partitioned into segments and each segment is confined within a
single data center. Therefore data center switches only need to learn
local MAC addresses, rather than learning both local and remote MAC
addresses.
3.7. ARP/ND Cache Table Scalability on Default Gateways
In case where data center default gateway functions are implemented
on PE routers of the VS as shown in Figure 4, since the ARP/ND cache
table on each PE router only needs to contain ARP/ND entries of local
CE hosts, the ARP/ND cache table size will not grow as the number of
data centers to be connected increases.
3.8. ARP/ND and Unknown Uncast Flood Avoidance
In VS, the flooding domain associated with a given virtual subnet
that has been extended across multiple data centers, has been
partitioned into segments and each segment is confined within a
single data center. Therefore, the performance impact on networks and
servers caused by the flooding of ARP/ND broadcast/multicast and
unknown unicast traffic is alleviated.
3.9. Path Optimization
Take the scenario shown in Figure 4 as an example, to optimize the
forwarding path for traffic between cloud users and cloud data
centers, PE routers located at cloud data centers (i.e., PE-1 and PE-
2), which are also data center default gateways, propagate host
routes for their local CE hosts respectively to remote PE routers
which are attached to cloud user sites (i.e., PE-3).
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As such, traffic from cloud user sites to a given server on the
virtual subnet which has been extended across data centers would be
forwarded directly to the data center location where that server
resides, since traffic is now forwarded according to the host route
for that server, rather than the subnet route.
Furthermore, for traffic coming from cloud data centers and forwarded
to cloud user sites, each PE router acting as a default gateway would
forward the traffic received from its local CE hosts according to the
best-match route in the corresponding VRF. As a result, traffic from
data centers to cloud user sites is forwarded along the optimal path
as well.
4. Limitations
4.1. Non-support of Non-IP Traffic
Although most traffic within and across data centers is IP traffic,
there may still be a few legacy clustering applications which rely on
non-IP communications (e.g., heartbeat messages between cluster
nodes). Since Virtual Subnet is strictly based on L3 forwarding,
those non-IP communications cannot be supported in the Virtual Subnet
solution. In order to support those few non-IP traffic (if present)
in the environment where the Virtual Subnet solution has been
deployed, the approach following the idea of "route all IP traffic,
bridge non-IP traffic" could be considered. That's to say, all IP
traffic including both intra-subnet and inter-subnet would be
processed by the Virtual Subnet process, while the non-IP traffic
would be resorted to a particular Layer2 VPN approach. Such unified
L2/L3 VPN approach requires ingress PE routers to classify the
traffic received from CE hosts before distributing them to the
corresponding L2 or L3 VPN forwarding processes.
Note that more and more cluster vendors are offering clustering
applications based on Layer 3 interconnection.
4.2. Non-support of IP Broadcast and Link-local Multicast
As illustrated before, intra-subnet traffic is forwarded at Layer3 in
the Virtual Subnet solution. Therefore, IP broadcast and link-local
multicast traffic cannot be supported by the Virtual Subnet solution.
In order to support the IP broadcast and link-local multicast traffic
in the environment where the Virtual Subnet solution has been
deployed, the unified L2/L3 overlay approach as described in Section
4.1 could be considered as well. That's to say, the IP broadcast and
link-local multicast would be resorted to the L2VPN forwarding
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process while the routable IP traffic would be processed by the
Virtual Subnet process.
4.3. TTL and Traceroute
As illustrated before, intra-subnet traffic is forwarded at Layer3 in
the Virtual Subnet context. Since it doesn't require any change to
the TTL handling mechanism of the BGP/MPLS IP VPN, when doing a
traceroute operation on one CE host for another CE host (assuming
that these two hosts are within the same subnet but are attached to
different sites), the traceroute output would reflect the fact that
these two hosts belonging to the same subnet are actually connected
via an virtual subnet emulated by ARP proxy, rather than a normal LAN.
In addition, for any other applications which generate intra-subnet
traffic with TTL set to 1, these applications may not be workable in
the Virtual Subnet context, unless special TTL processing for such
case has been implemented (e.g., if the source and destination
addresses of a packet whose TTL is set to 1 belong to the same
extended subnet, both ingress and egress PE routers MUST NOT
decrement the TTL of such packet. Furthermore, the TTL of such packet
SHOULD NOT be copied into the TTL of the transport tunnel and vice
versa).
5. Security Considerations
This document doesn't introduce additional security risk to BGP/MPLS
IP VPN, nor does it provide any additional security feature for
BGP/MPLS IP VPN.
6. IANA Considerations
There is no requirement for any IANA action.
7. Acknowledgements
Thanks to Dino Farinacci, Himanshu Shah, Nabil Bitar, Giles Heron,
Ronald Bonica, Monique Morrow, Rajiv Asati, Eric Osborne, Thomas
Morin, Martin Vigoureux, Pedro Roque Marque, Joe Touch and Wim
Henderickx for their valuable comments and suggestions on this
document.
8. References
8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
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8.2. Informative References
[RFC4364] Rosen. E and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, February 2006.
[MVPN] Rosen. E and Aggarwal. R, "Multicast in MPLS/BGP IP VPNs",
draft-ietf-l3vpn-2547bis-mcast-10.txt, Work in Progress,
Janurary 2010.
[RFC925] Postel, J., "Multi-LAN Address Resolution", RFC-925, USC
Information Sciences Institute, October 1984.
[RFC1027] Smoot Carl-Mitchell, John S. Quarterman, "Using ARP to
Implement Transparent Subnet Gateways", RFC 1027, October
1987.
[RFC4389] D. Thaler, M. Talwar, and C. Patel, "Neighbor Discovery
Proxies (ND Proxy) ", RFC 4389, April 2006.
[RFC5798] S. Nadas., "Virtual Router Redundancy Protocol", RFC 5798,
March 2010.
[RFC4761] Kompella, K. and Y. Rekhter, "Virtual Private LAN Service
(VPLS) Using BGP for Auto-Discovery and Signaling", RFC
4761, January 2007.
[RFC4762] Lasserre, M. and V. Kompella, "Virtual Private LAN Service
(VPLS) Using Label Distribution Protocol (LDP) Signaling",
RFC 4762, January 2007.
[802.1AB] IEEE Standard 802.1AB-2009, "Station and Media Access
Control Connectivity Discovery", September 17, 2009.
[802.1Qbg] IEEE Draft Standard P802.1Qbg/D2.0, "Virtual Bridged Local
Area Networks -Amendment XX: Edge Virtual Bridging", Work
in Progress, December 1, 2011.
[RFC6820] Narten, T., Karir, M., and I. Foo, "Problem Statement for
ARMD", RFC 6820, January 2013.
Authors' Addresses
Xiaohu Xu
Huawei Technologies,
Beijing, China.
Phone: +86 10 60610041
Email: xuxiaohu@huawei.com
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Robert Raszuk
Email: robert@raszuk.net
Susan Hares
Email: shares@ndzh.com
Yongbing Fan
Guangzhou Institute, China Telecom
Guangzhou, China.
Phone: +86 20 38639121
Email: fanyb@gsta.com
Christian Jacquenet
Orange
Rennes France
Email: christian.jacquenet@orange.com
Truman Boyes
Bloomberg LP
Phone: +1 2126174826
Email: tboyes@bloomberg.net
Brendan Fee
Extreme Networks
9 Northeastern Blvd.
Salem, NH, 03079
Email: bfee@enterasys.com
