Internet DRAFT - draft-ietf-l3vpn-virtual-subnet
draft-ietf-l3vpn-virtual-subnet
Network Working Group X. Xu
Internet-Draft Huawei
Intended status: Informational R. Raszuk
Expires: June 5, 2015 Mirantis Inc.
S. Hares
Huawei
Y. Fan
China Telecom
C. Jacquenet
Orange
T. Boyes
Bloomberg LP
B. Fee
Extreme Networks
December 2, 2014
Virtual Subnet: A L3VPN-based Subnet Extension Solution
draft-ietf-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 for building Layer3 network virtualization overlays
within and/or across data centers.
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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material or to cite them other than as "work in progress."
This Internet-Draft will expire on June 5, 2015.
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Copyright Notice
Copyright (c) 2014 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
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the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Solution Description . . . . . . . . . . . . . . . . . . . . 5
3.1. Unicast . . . . . . . . . . . . . . . . . . . . . . . . . 5
3.1.1. Intra-subnet Unicast . . . . . . . . . . . . . . . . 5
3.1.2. Inter-subnet Unicast . . . . . . . . . . . . . . . . 6
3.2. Multicast . . . . . . . . . . . . . . . . . . . . . . . . 8
3.3. CE Host Discovery . . . . . . . . . . . . . . . . . . . . 9
3.4. ARP/ND Proxy . . . . . . . . . . . . . . . . . . . . . . 9
3.5. CE Host Mobility . . . . . . . . . . . . . . . . . . . . 9
3.6. Forwarding Table Scalability on Data Center Switches . . 10
3.7. ARP/ND Cache Table Scalability on Default Gateways . . . 10
3.8. ARP/ND and Unknown Uncast Flood Avoidance . . . . . . . . 10
3.9. Path Optimization . . . . . . . . . . . . . . . . . . . . 10
4. Limitations . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.1. Non-support of Non-IP Traffic . . . . . . . . . . . . . . 11
4.2. Non-support of IP Broadcast and Link-local Multicast . . 11
4.3. TTL and Traceroute . . . . . . . . . . . . . . . . . . . 11
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
7. Security Considerations . . . . . . . . . . . . . . . . . . . 12
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 12
8.1. Normative References . . . . . . . . . . . . . . . . . . 12
8.2. Informative References . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
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1. Introduction
For business continuity purpose, 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.
To achieve subnet extension across multiple Infrastructure-as-
a-Service (IaaS) cloud data centers in a scalable way, the following
requirements and challenges must be considered:
a. 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.
b. Forwarding Table Scalability: With the development of server
virtualization technologies, it's not uncommon for a single cloud
data center to contain millions of VMs. This number already
implies a big challenge on the forwarding table scalability of
data center switches. Provided multiple data centers of such
scale were interconnected at layer2, this challenge would become
even worse.
c. ARP/ND Cache Table Scalability: [RFC6820] notes that the Address
Resolution Protocol (ARP)/Neighbor Discovery (ND) cache tables
maintained on default gateways within cloud data centers can
raise scalability issues. Therefore, it's very useful if the
ARP/ND cache table size could be prevented from growing by
multiples as the number of data centers to be connected
increases.
d. ARP/ND and Unknown Unicast Flooding: It's well-known that the
flooding of ARP/ND broadcast/multicast and unknown unicast
traffic within large Layer2 networks would affect the performance
of networks and hosts. As multiple data centers with each
containing millions of VMs are interconnected at layer2, the
impact of flooding as mentioned above would become even worse.
As such, it becomes increasingly important to avoid the flooding
of ARP/ND broadcast/multicast and unknown unicast traffic across
data centers.
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e. 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 an
unnecessary consumption of the bandwidth resource between data
centers. 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
resource between data centers
This document describes a L3VPN-based subnet extension solution
referred to as Virtual Subnet (VS), which can be used for data center
interconnection while addressing all of the requirements and
challenges as mentioned above. In addition, since VS is mainly built
on proven technologies such as BGP/MPLS IP VPN [RFC4364] and ARP/ND
proxy [RFC0925][RFC1027][RFC4389], those service providers offering
IaaS public cloud services could rely upon their existing BGP/MPLS IP
VPN infrastructures and their corresponding experiences to realize
data center interconnection.
Although Virtual Subnet is described in this document as an approach
for data center interconnection, it actually could be used within
data centers as well.
Note that the approach described in this document is not intended to
achieve an exact emulation of L2 connectivity and therefore it 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.
1.1. Requirements Language
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].
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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 |
+------------+---------+--------+ +------------+---------+--------+
| 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 own local CE hosts respectively
and then advertise them via the BGP/MPLS IP VPN 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
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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 |
+------------+---------+--------+ +------------+---------+--------+
| 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
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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 |
+------------+---------+--------+ +------------+---------+--------+
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
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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 technologies [RFC6513] could be directly used without any
change. 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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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) or
VSI Discovery and Configuration Protocol (VDP), 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
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
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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
When default gateway functions are implemented on PE routers as shown
in Figure 4, the ARP/ND cache table on each PE router only needs to
contain ARP/ND entries of local CE hosts As a result, the ARP/ND
cache table size would 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, is partitioned
into segments and each segment is confined within a single data
center. Therefore, the performance impact on networks and servers
imposed 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 the 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 acting as default gateways, propagate host routes
for their own local CE hosts respectively to remote PE routers which
are attached to cloud user sites (i.e., PE-3). As such, the 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 the traffic
is now forwarded according to the host route for that server, rather
than the subnet route. Furthermore, for the traffic coming from
cloud data centers and forwarded to cloud user sites, each PE router
acting as a default gateway would forward the traffic according to
the best-match route in the corresponding VRF. As a result, the
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traffic from data centers to cloud user sites is forwarded along an
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 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
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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. 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.
6. IANA Considerations
There is no requirement for any IANA action.
7. 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.
8. References
8.1. Normative References
[RFC0925] Postel, J., "Multi-LAN address resolution", RFC 925,
October 1984.
[RFC1027] Carl-Mitchell, S. and J. Quarterman, "Using ARP to
implement transparent subnet gateways", RFC 1027, October
1987.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, February 2006.
[RFC4389] Thaler, D., Talwar, M., and C. Patel, "Neighbor Discovery
Proxies (ND Proxy)", RFC 4389, April 2006.
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[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.
[RFC5798] Nadas, S., "Virtual Router Redundancy Protocol (VRRP)
Version 3 for IPv4 and IPv6", RFC 5798, March 2010.
[RFC6513] Rosen, E. and R. Aggarwal, "Multicast in MPLS/BGP IP
VPNs", RFC 6513, February 2012.
8.2. Informative References
[RFC6820] Narten, T., Karir, M., and I. Foo, "Address Resolution
Problems in Large Data Center Networks", RFC 6820, January
2013.
Authors' Addresses
Xiaohu Xu
Huawei
Email: xuxiaohu@huawei.com
Robert Raszuk
Mirantis Inc.
Email: robert@raszuk.net
Susan Hares
Huawei
Email: shares@ndzh.com
Yongbing Fan
China Telecom
Email: fanyb@gsta.com
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Christian Jacquenet
Orange
Email: christian.jacquenet@orange.com
Truman Boyes
Bloomberg LP
Email: tboyes@bloomberg.net
Brendan Fee
Extreme Networks
Email: bfee@enterasys.com
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