Internet DRAFT - draft-fang-l3vpn-virtual-ce
draft-fang-l3vpn-virtual-ce
INTERNET-DRAFT Luyuan Fang
Intended Status: Standards track Microsoft
Expires: January 4, 2015 John Evans
David Ward
Rex Fernando
Cisco
Ning So
Vinci Systems
Nabil Bitar
Verizon
Maria Napierala
AT&T
July 4, 2014
BGP IP MPLS VPN Virtual CE
draft-fang-l3vpn-virtual-ce-03
Abstract
This document describes the architecture and solutions of using
virtual Customer Edge (vCE) of BGP IP MPLS VPN. The solution is aimed
at providing efficient service delivery capability through CE
virtualization, and is especially beneficial in virtual Private Cloud
(vPC) environments when extending IP MPLS VPN into tenant virtual
Data Center containers. This document includes: BGP IP MPLS VPN
virtual CE architecture; Control plane and forwarding options; Data
Center orchestration processes; integration with existing WAN
enterprise VPNs; management capability requirements; and security
considerations. The solution is generally applicable to any BGP IP
VPN deployment. The virtual CE solution is complementary to the
virtual PE solutions.
Today's data center's require multi-tenancy and mechanisms to
establish overlay network connectivity. This document describes one
approach to enabling data center network connectivity.
Status of this Memo
This Internet-Draft is submitted to IETF 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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time. It is inappropriate to use Internet-Drafts as reference
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The list of current Internet-Drafts can be accessed at
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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 . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1 Terminology . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2 Problem statement . . . . . . . . . . . . . . . . . . . . . 6
1.3 Scope of the document . . . . . . . . . . . . . . . . . . . 6
2. Virtual CE Architecture and Reference Model . . . . . . . . . . 7
2.1 Virtual CE . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 Architecture . . . . . . . . . . . . . . . . . . . . . . . . 8
3. Control Plane . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.1 vCE Control Plane . . . . . . . . . . . . . . . . . . . . . 10
4. Forwarding Plane . . . . . . . . . . . . . . . . . . . . . . . 11
4.1 Forwarding between vCE and PE/vPE . . . . . . . . . . . . . 11
4.2 Forwarding between vCE and VM . . . . . . . . . . . . . . . 11
5. Addressing and QoS . . . . . . . . . . . . . . . . . . . . . . 11
5.1 Addressing . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.2 QoS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
6. Management plane . . . . . . . . . . . . . . . . . . . . . . . 12
6.1 Network abstraction and management . . . . . . . . . . . . . 12
6.2 Service VM Management . . . . . . . . . . . . . . . . . . . 12
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7. Orchestration and IP VPN inter-provisioning . . . . . . . . . . 12
7.1 DC Instance to WAN IP VPN instance "binding" Requirements . 12
7.2. Provisioning/Orchestration . . . . . . . . . . . . . . . . 13
7.2.1 vCE Push model . . . . . . . . . . . . . . . . . . . . . 13
7.2.1.1 Inter-domain provisioning vCE Push Model . . . . . . 14
7.2.1.2 Cross-domain provisioning vCE Push Model . . . . . . 14
7.1.1 vCE Pull model . . . . . . . . . . . . . . . . . . . . . 15
8. vCE and vPE interaction . . . . . . . . . . . . . . . . . . . . 16
8.1 Traditional vCE-PE connectivity . . . . . . . . . . . . . . 16
8.2 vCE-vPE connectivity . . . . . . . . . . . . . . . . . . . . 16
8.2.1 Co-located vCE-vPE connectivity with vPE Model 1 . . . . 17
8.2.2 Co-located vCE-vPE connectivity with vPE Model 2 . . . . 18
8. Security Considerations . . . . . . . . . . . . . . . . . . . . 18
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 18
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
10.1 Normative References . . . . . . . . . . . . . . . . . . . 18
10.2 Informative References . . . . . . . . . . . . . . . . . . 19
11. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 20
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 20
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1. Introduction
In the typical enterprise BGP/MPLS IP VPN [RFC4364] deployment, the
Provider Edge (PE) and Customer Edge (CE) are physical routers which
support the PE and CE functions. With the recent development of cloud
services, using virtual instances of PE or CE functions, which reside
in a compute device such as a server, can be beneficial to emulate
the same logical functions as the physical deployment model but now
achieved via cloud based network virtualization principles.
This document describes IP VPN virtual CE (vCE) solutions, while
Virtual PE (vPE) concept and implementation options are discussed in
[I-D.fang-l3vpn-virtual-pe], [I-D.ietf-l3vpn-end-system]. vPE and vCE
solutions provide two avenues to realize network virtualization.
1.1 Terminology
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].
Term Definition
----------- --------------------------------------------------
AAA Authentication, Authorization, and Accounting
ACL Access Control List
3GPP 3rd Generation Partnership Project (3GPP)
AS Autonomous Systems
ASBR Autonomous Systems Border Router
BFD Bidirectional Forwarding Detection
BGP Border Gateway Protocol
CE Customer Edge
DB Data Base
DMZ Demilitarized Zone, a.k.a. perimeter networking
ED End device: where Guest OS, Host OS/Hypervisor,
applications, VMs, and virtual router may reside
FE Front End
FIB Forwarding Information Base
Forwarder L3VPN forwarding function
FRR Fast Re-Route
FTP File Transfer Protocol
GRE Generic Routing Encapsulation
HTTP Hypertext Transfer Protocol
Hypervisor Virtual Machine Manager
I2RS Interface to Routing System
LDAP Lightweight Directory Access Protocol
MP-BGP Multi-Protocol Border Gateway Protocol
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NVGRE Network Virtualization using GRE
OSPF Open Shortest Path First
PE Provider Edge
QinQ Provider Bridging, stacked VLANs
RR Route Reflector
SDN Software Defined Network
SLA Service Level Agreement
SMTP Simple Mail Transfer Protocol
ToR Top of the Rack switch
VI Virtual Interface
vCE virtual Customer Edge Router
vLB virtual Load Balancer
VM Virtual Machine
VLAN Virtual Local Area Network
vPC virtual Private Cloud
vPE virtual Provider Edge Router
VPN Virtual Private Network
vRR virtual Route Reflector
vSG virtual Security Gateway
VXLAN Virtual eXtensible Local Area Network
WAN Wide Area Network
Definitions:
Virtual CE (vCE): A virtual instance of the Customer Edge (CE)
routing function which resides in one or more network or compute
devices. For example, the vCE data plane may reside in an end device,
such as a server, and as co-resident with application Virtual
Machines (VMs) on the server; the vCE control plane may reside in the
same device or in a separate entity such as a controller.
Network Container/Tenant Container: An abstraction of a set of
network and compute resources which can be physical and virtual,
providing the cloud services for a tenant. One tenant can have more
than one Tenant Containers.
Zone: A logical grouping of VMs and service assets within a tenant
container. Different security policies may be applied within and
between zones.
DMZ: Demilitarized zone, a.k.a. perimeter networking. It is often a
machine or a small subnet that sits between a trusted internal
network, such as a corporate private LAN, and an un-trusted external
network, such as the public Internet. Typically, the DMZ contains
devices accessible to Internet traffic, such as Web (HTTP) servers,
FTP servers, SMTP (e-mail) servers and DNS servers.
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1.2 Problem statement
With the growth of cloud services and the increase in the number of
CE devices, routers/switches, and appliances, such as Firewalls (FWs)
and Load Balancers (LBs), that need to be supported, there are
benefits to virtualize the Data Center tenant container. The
virtualized container can increase resource sharing, optimize routing
and forwarding of inter-segment and inter-service traffic, and
simplify design, provisioning, and management.
The following two aspects of the virtualized Data Center tenant
container for the IP VPN CE solution are discussed in this document.
1. Architecture re-design for virtualized DC.
The optimal architecture of the virtualized container includes
virtual CE, virtual appliances, application VMs. All these functions
are co-resitents on virtualized servers. In this arrangement, CEs and
appliances can be created and removed easily on demand, and the
virtual CE can interconnect the virtual appliances (e.g., FW, LB,
NAT), applications (e.g., Web, App., and DB) in a co-located fashion
for simplicity, routing/forwarding optimization, and easier service
chaining. Virtualizing these functions on a per-tenant basis provides
simplicity for the network operator in regards to managing per tenant
service orchestration, tenant container moves, capacity planning
across tennants and per-tenant policies.
2. Provisioning/orchestration. Two issues need to be addressed:
a) The provisioning/orchestration system of the virtualized data
center need to support VM life cycle and VM migration.
b) The provisioning/orchestration systems of the DC and the WAN
networks need to be coordinated to support end-to-end IP VPN from DC
to DC or from DC to enterprise remote office in the same VPN. The DC
and the WAN network are often operated by separate departments, even
if they belong to the same provider. Today, the process of inter-
connecting is slow and painful, and automation is highly desirable.
1.3 Scope of the document
It is assumed that the readers are familiar with BGP/MPLS IP VPN
[RFC4364] terms and technologies, the base technology and its
operation are not reviewed in details in this document.
As the majority (all in some networks) of applications are IP, this
vCE solution is focusing on IP VPN solutions to cover the most common
cases and keep matters as simple as possible.
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2. Virtual CE Architecture and Reference Model
2.1 Virtual CE
As described in [RFC4364], IP uses a "peer model" - the customers'
edge routers (CE routers) exchange routes with the Service Provider's
edge routers (PE routers); the CEs do not peer with each other. MP-
BGP [RFC4271, RFC4760] is used between the PEs (often with RRs) which
have a particular VPN attached to them to exchange the VPN routes. A
CE sends IP packets to the PE; no VPN labels for packets forwarded
between CE and PE.
A virtual CE (vCE) as defined in this document is a software instance
of IP VPN CE function which can reside in ANY network or compute
devices. For example, a vCE MAY reside in an end device, such as a
server in a Data Center, where the application VMs reside. The CE
functionality and management models remain the same as defined in
[RFC4364] regardless of whether the CE is physical or virtual.
Using the virtual CE model, the CE functions CAN easily co-located
with the VM/applications, e.g., in the same server. This allows
tenant inter-segment and inter-service routing to be optimized.
Likewise the vCE can be in a separate server (in the same DC rack or
across racks) than the application VMs, in which case VMs would
typically use standard L2 technologies to access the vCE via the DC
network.
Similar to the virtual PE solution, the control and forwarding of a
virtual CE can be on the same device, or decoupled and reside on
different physical devices. The provisioning of a virtual CE,
associated applications, and the tenant network container can be
supported through DC orchestration systems.
Unlike a physical or virtual PE which can support multi-tenants, a
physical or virtual CE supports a single tenant only. A single tenant
CAN use multiple physical or virtual CEs. An end device, such as a
server, CAN support one or more vCE(s). While the vCE is defined as a
single tenant device, each tenant can have multiple logical
departments which are under the tenants administrative control,
requiring logical separation, this is the same model as today's
physical CE deployments.
Virtual CE and virtual PE are complimentary approaches for extending
IP VPN into tenant containers. In the vCE solution, there is no IP
VPN within the data center or other type of service network, the vCE
can connect to the PE which is a centralized IP VPN PE/Gateway/ASBR,
or connect to distributed vPE on a server or on the Top of the Rack
switch (ToR). Virtual CE can be used to extend the SP managed CE
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solution to create new cloud enabled services and provide the same
topological model and features that are consistent with the physical
CE systems.
2.2 Architecture
Figure 1 illustrates the topology where vCE is resident in the
servers where the applications are hosted.
.''---'''---''.
( )
( IP/MPLS )
( WAN )
WAN '--,,,_,,,--'
----------------|----------|------------------
Service/DC | |
Network +-------+ +-------+
|Gateway|---|Gateway|
| PE | | PE |
+-------+ +-------+
| ,---. |
.---. ( '.---.
( ' ' ')
(' Data Center )
(. Fabric .)
( ( ).--'
/ ''--' '-''--' \
/ / \ \
+-------+ +---+---+ +-------+ +-------+
| vCE | |vCE|vCE| | vCE | |vCE|vCE|
+---+---+ +---+---+ +---+---+ +---+---+
|VM |VM | |VM |VM | |VM |VM | |VM |VM |
+---+---+ +---+---+ +---+---+ +---+---+
|VM |VM | |VM |VM | |VM |VM | |VM |VM |
+---+---+ +---+---+ +---+---+ +---+---+
End Device End Device End Device End Device
Figure 1. Virtualized Data Center with vCE
Figure 1 shows above vCE solution in a virtualized Data Center with
application VMs on the servers. One or more vCEs MAY be used on each
server.
The vCEs logically connect to the PEs/Gateway PEs to join the
particular IP VPN which the tenant belongs to. Gateway PEs connect to
the IP MPLS WAN network for inter-DC and DC to enterprise VPN sites
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connection. The server physically connects to the DC Fabric for
packet forwarding.
,---. ,---.
.--.( ) .--.( )
( ' '.---. ( ' '.---.
(' L3VPN ) (' Internet )
'..( ).' '..( ).'
'--'---'' '--'---''
+---+ +---+ +---+ +---+
|PE | |PE | | R | | R |
+---+ +---+ +---+ +---+
| | | |
""""""""""""""""""|"""""""|""""""""""""""|"""""""|"""""""""""""""""
" End Device | | +----+ | "
" (e.g. a server) +-------+-----+ +----|vSG |----+ "
" | | +----+ "
" +----+ "
" +---------------------|vCE |-----------+ "
" | +----+ | "
" +----+ | +----+ | | +----+ "
" |vLB |-| |vLB |--+-----------+ +--|vLB | "
" +----+ | +----+ | | +----+ "
" | | +----+ | "
" | | +------|vSG |-+------+ "
" | | | +----+ | "
" '''''''|'''''''''''|''''' ''''''|'''''''''|''''''''''|''''''''' "
" ' +--------+ +--------+ ' ' +-------+ +-------+ +-----------+ ' "
" ' | Apps/ | | Apps/ | ' ' | Apps/ | | Apps/ | |Apps |Apps | ' "
" ' | VMs | | VMs | ' ' | VMs | | VMs | |VMs |VMs | ' "
" ' | | | | ' ' | | | | |ZONE3|ZONE4| ' "
" ' | Public | |Protect-| ' ' | | | | +-----+-----+ ' "
" ' | Zone | | ed FE | ' ' | ZONE1 | | ZONE2 | |Apps |Apps | ' "
" ' | (DMZ) | | | ' ' | | | | |VMs |VMs | ' "
" ' | | | | ' ' | | | | |ZONE5|ZONE6| ' "
" ' +--------+ +--------+ ' ' +-------+ +-------+ +-----------+ ' "
" ' Front-end Zone ' ' Back-end Zone ' "
" ' ' ' ' "
" ''''''''''''''''''''''''' ''''''''''''''''''''''''''''''''''''' "
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
Figure 2. A Virtualized Container with vCE in an End Device
An end device shown in Figure 2 is a physical server supporting
multiple virtualized appliances and application, and hosts multiple
client VMs. An end device shown in Figure 2 is a physical server
supporting multiple In the traditional deployment, the topology often
involves multiple physical CEs, physical Security Gateways and Load
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Balancers residing in the same Data Center.
The virtualized approach provides the benefit of reduced number of
physical devices, simplified management, optimal routing due to the
co-location of vCE, services, and client VMs.
While the above diagram represents a simplified view of all of the
tenant service and application VMs residing in the same physical
server, the above model can also be represented with the VMs spread
across many physical servers and the DC network would provide the
physical inter-connectivity while the vCE and the VMs connected to
the vCE form the logical connections.
3. Control Plane
3.1 vCE Control Plane
The vCE control plane can be distributed or centralized.
1) Distributed control plane
vCE CAN exchange BGP routes with PE or vPE for the particular IP VPN
as described in [RFC4364].
The vCE needs to support BGP if this approach is used.
The advantage of distributed protocols is to avoid single point of
failure and bottleneck. Service chaining can be easily and
efficiently supported in this approach.
BGP as PE-CE protocol is used in about 70% of cases in typical
Enterprise IP VPN PE-CE connections. BGP supports rich policy
compared to other alternatives.
2) Static routing. It is used in about 30% of cases in Enterprise IP
VPN PE-CE connections. It MAY be used if the operator prefers.
2. Using controller approach
Using controller is the Software Defined Nework (SDN) approach. A
controller can be distributed or centralized. The central controller
performs the control plane functions, and sends instructions to the
vCE on the end devices to configure the data plane.
This requires standard interface to routing system (I2RS). The
Interface to Routing System (I2RS) is work in progress in IETF [I-
D.ward-irs-framework], [I-D.rfernando-irs-framework-requirement].
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4. Forwarding Plane
4.1 Forwarding between vCE and PE/vPE
No MPLS forwarding is required between PE and CE in typical PE-CE
connection scenarios, though MPLS label forwarding is required for
implementing Carriers' Carrier (CSC) model.
IPv4 and IPv6 packet forwarding MUST be supported.
Native fabric CAN be used to support isolation between vCEs to PE
connections.
Examples of native fabric include:
- VLANs [IEEE 802.1Q], Virtual Local Area Network- IEEE 802.1ad
[IEEE 802.1ad]/QinQ, Provider Bridge
Or overlay segmentation with better scalability:
- VXLANs [I-D.mahalingam-dutt-dcops-vxlan], Virtual Extensible
LAN- NVGRE [I-D.sridharan-virtualization-nvgre], Network
Virtualization using GRE
Note the the above references for overlay network are currently work
in progress in IETF.
4.2 Forwarding between vCE and VM
If the vCE and the VM the vCE is connecting are co-located in the
same server, the connection is internal to the server, no external
protocol involved.
If the vCE and the VM the vCE is connecting are located in different
devices, standard external protocols are needed. The forwarding can
be native or overlay techniques as listed in the above sub-section.
5. Addressing and QoS
5.1 Addressing
IPv4 and IPv6 addressing MUST be supported.
IP address allocation for vCEs and applications/client:
1) IP address MAY be assigned by central management/provisioning
with predetermined blocks through planning process.
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2) IP address MAY be obtained through DHCP server.
Address space separation: The IP addresses used for clients in the IP
VPNs in the Data Center SHOULD be in separate address blocks outside
the blocks used for the underlay infrastructure of the Data Center.
The purpose is to protect the Data Center infrastructure from being
attacked if the attacker gain access of the tenant VPNs.
5.2 QoS
Differentiated Services [RFC2475] Quality of Service (QoS) is
standard functionality for physical CEs and MUST be supported on vCE.
This is important to ensure seamless end-to-end SLA from IP VPN in
the WAN into service network/Data center. The use of MPLS Diffserv
tunnel model Pipe Mode (RFC3270) with explicit null LSP must be
supported.
6. Management plane
6.1 Network abstraction and management
The use of vCE with single tenant virtual service instances can
simplify management requirements as there is no need to discover
device capabilities, track tenant dependencies and manage service
resources.
vCE North bound interface SHOULD be standards based.
The Interface to Routing System (I2RS) is work in progress in IETF
[I-D.ward-irs-framework], [I-D.rfernando-irs-framework-requirement].
vCE element management MUST be supported, it can be in the similar
fashion as for physical CE, without the hardware aspects.
6.2 Service VM Management
Service VM Management SHOULD be hypervisor agnostic, e.g. On demand
service VMs turning-up SHOULD be supported.
The management tool SHOULD be open standards.
7. Orchestration and IP VPN inter-provisioning
7.1 DC Instance to WAN IP VPN instance "binding" Requirements
- MUST support service activation in the physical and virtual
environment.
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For example, assign VLAN to correct VRF.
- MUST support per VLAN Authentication, Authorization, and Accounting
(AAA).
The PE function is an OA&M boundary.
- MUST be able to apply other policies to VLAN.
For example, per VLAN QOS, ACLs.
- MUST ensure that WAN IP VPN state and Data cCentre state are
dynamically synchronized.
Ensure that there is no possibility of customer being connected to
the wrong VRF. For example, remove all tenant state when service
instance terminated.
- MUST integrate with existing WAN IP VPN provisioning processes.
- MUST scale to at least 10,000 tenant service instances.
- MUST cope with rapid (sub minute) tenant mobility.
- MAY support Automated cross provisioning accounting correlation
between WAN IP VPN and cloud/DC for the same tenant.
- MAY support Automated cross provisioning state correlation between
WAN IP VPN and cloud/DC/extended Data Center for the same tenant.
7.2. Provisioning/Orchestration
There are two primary approaches for IP VPN provisioning - push and
pull, both CAN be used for provisioning/orchestration.
7.2.1 vCE Push model
Push model: It is a top down approach - push IP VPN provisioning from
network management system or other central control provisioning
systems to the IP VPN network elements.
This approach supports service activation and it is commonly used in
the existing IP VPN enterprise deployment. When existing the IP VPN
solution into the cloud/data center or separate Data Center, it MUST
support off-line accounting correlation between the WAN IP VPN and
the cloud/DC IP VPN for the tenant, the systems SHOULD be able to
bind interface accounting to particular tenant. It MAY requires
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offline state correlation as well, for example, bind interface state
to tenant.
7.2.1.1 Inter-domain provisioning vCE Push Model
Provisioning process:
1) Cloud/DC orchestration configures vCE.
2) Orchestration initiates WAN IP VPN provisioning; passes connection
IDs (e.g., of VLAN/VXLAN) and tenant context to WAN IP VPN
provisioning systems.
3) WAN IP VPN provisioning system provisions PE VRF and other
policies per normal enterprise IP VPN provisioning processes.
This model requires the following:
- The DC Orchestration system or the WAN IP VPN provisioning system
know the topology inter-connecting the DC and WAN VPN. For
example, which interface on the WAN core device connects to which
interface on the DC PE.
- Offline state correlation.
- Offline accounting correlation.
- Per SP integration.
Dynamic BGP session between PE/vPE and vCE MAY be used to automate
the PE provisioning in the PE-vCE model, that will remove the needs
for PE configuration. Other protocols can be used for this purpose as
well, for example, use Enhanced Interior Gateway Routing Protocol
(EIGRP) for dynamic neighbour relationship establishment.
The dynamic routing Prevents the need to configure the PEs in PE-vCE
model.
Caution: This is only under the assumption that the DC provisioning
system is trusted and could support dynamic establishment of PE-vCE
BGP neighbor relationships, for example, the WAN network and the
cloud/DC belongs to the same Service Provider.
7.2.1.2 Cross-domain provisioning vCE Push Model
Provisioning Process:
1) Cross-domain orchestration system initiates DC orch.
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2) DC orchestration system configures vCE
3) DC orchestration system passes back VLAN/VXLAN and tenant context
to Cross-domain orchestration system
4) Cross-domain orchestration system initiates WAN IP VPN
provisioning
5) WAN IP VPN provisioning system provisions PE VRF and other
policies as per normal enterprise IP VPN provisioning processes.
This model requires the following:
- Cross-domain orchestration system knows the topology connecting the
DC and WAN IP VPN, for example, which interface on core device
connects to which interface on DC PE.- Offline state correlation.
- Offline accounting correlation.
- Per SP integration.
7.1.1 vCE Pull model
Pull model: It is a bottom-up approach - pull from network elements
to network management/AAA based upon data plane or control plane
activity. It supports service activation, this approach is often used
in broadband deployment. Dynamic accounting correlation and dynamic
state correlation are supported. For example, session based
accounting is implicitly includes tenant context state correlation,
as well as session based state which implicitly includes tenant
context.
Inter-domain Provisioning:
Process:
1) Cloud/DC orchestration system configures vCE
2) Cloud/DC Orchestration system primes WAN IP VPN provisioning/AAA
for new service, passes connection IDs (e.g., VLAN/VXLAN) and tenant
context WAN IP VPN provisioning systems.
3) Cloud/DC PE detects new VLAN, send Radius Access-Request.
4) Radius Access-Accept with VRF and other policies.
This model requires VLAN/VLAN information and tenant context to
passed on a per transaction basis. In practice, it may simplify to
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use DC orchestration updating LDAP directory
Auto accounting correlation and auto state correlation is supported.
8. vCE and vPE interaction
A vPE ([I-D.fang-l3vpn-virtual-pe] [I-D.ietf-l3vpn-end-system]) is
treating the VMs in the server as a virtual CE. In this section, the
relationship between the vPE and such vCE is discussed. vPE can
support one of the following two models:
Model 1: a limited control-plane functionality that advertises
local VPN routes to a controller and receive VPN routes from the
controller.
Model 2: a control plane component physically separated from the
forwarding component that fully performs the control plane routing
functionality and communicate FIB entries to the vPE forwarding
entity implemented on servers.
A vCE provides subnet routing, firewalling or SLB services to host
VMs. The underlying connectivity between the vCE and these VMs can be
at layer 2 or layer 3. In addition, the vCE can be connected to other
vCEs over Layer 2 or using an IP VPN infrastructure. In this section,
the focus is on IP VPN connectivity and more importantly on the
interaction between a vCE, a traditional PE (simply referred to as
PE), and between a vCE and a vPE.
8.1 Traditional vCE-PE connectivity
This connectivity is described in BGP/MPLS IPVPN [RFC4364]. The only
distinction being that the VE is a virtual CE. The vCE attaches to
the layer 3 PE using a layer2 logical connection, e.g., Ethernet
VLAN, or a tunnel (e.g., IP/GRE, VXLAN) that are presented as IP
interfaces to a corresponding VRF at the PE. Routing between the vCE
and PE can be static or based on a dynamic routing protocol (e.g.,
OSPF, BGP). A routing protocol, in addition to enabling the exchange
of routing information between the PE and vCE, provides liveliness
check between the vCE and the PE. In the absence of a dynamic routing
protocol, the vCE must support a mechanism that provides for
liveliness check, or an out-of-band mechanism must be implemented to
monitor the liveliness of a vCE and a connected PE, and effect
routing changes upon a failure. Options for in-band liveliness check
include IP BFD [RFC5880], Ethernet Continuity Check (CC) [IEEE
802.1ag], and IP ping [RFC4560]. IP BFD must be supported while the
other mechanisms are optional.
8.2 vCE-vPE connectivity
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In this model, the vcE and vPE forwarding plane can be: (1) co-
located on the same end device, e.g., a server, or (2) located on
different servers. In addition, the control plane interaction differs
between vPE model 1 and model 2.
8.2.1 Co-located vCE-vPE connectivity with vPE Model 1
In vPE Model 1, there is a control plane component of the vPE
implemented on the end-server (e.g., [I-D.ietf-l3vpn-end-system], [I-
D.fang-l3vpn-virtual-pe]). In addition, there is a control plane
component implemented on a separate control plane entity (out-of-
band) that enables the exchange of routing information among vPEs. In
[I-D.ietf-l3vpn-end-system], the out-of-band control plane component
is referred to as router server; in [I-D.fang-l3vpn-virtual-pe], it
is referred as vPE-C. There are two cases that must be considered:
Case 1-A: vCE to vPE local route exchange on a server / vPE-C
Case 1-B: vCE to route server / vPE-C route exchange.
In these two cases, the vPE control plane or route server must send
the CE a default route with next hop being the co-located vPE
forwarding plane entity.
In case 1-A, the vCE must send local routes to the vPE control plane
with itself being the next hop. The vPE control plane entity in turn
updates the out-of-band control entity (e.g., route server) with
routes reachable via the local CE, as VPN routes, with itself being
the next hop for these routes. The vPE also receives from the route
server VPN routes reachable via other vPEs [end-system]. It should be
noted in this case, that the vCE must be able support one or more
routing contexts, each with separate attachment circuit to the vPE.
Each such routing context must be associated with a VPN and one or
more VPNs must be supported.
In case 1-B, the vCE must have a control channel with a route server.
There must be a control channel per vCE routing context or
alternatively must allow the unambiguous multiplexing of routes that
belong to different routing context on the same channel. The vCE
sends routes reachable via the vCE to the route server with itself
being the next hop. The route server must learn from the co-located
vPE control plane component reachability to the local vCE IP address
used as next hop. This IP address must be exchanged between the vCE
and vPE in-band over a corresponding attachment circuit that
identifies the routing context . Alternatively, the route server/vPE-
C must be programmed with the association of the vCE control channel,
a VPN and an end-device IP address. As a result, the route
server/vPE-C must populate the vPE distributed control plane with the
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corresponding routes as non-VPN routes and the vPE must respond with
VPN routes that correspond to each of these routes. Alternatively,
routes reachable via a vCE must be defined via in portal per routing
context and therefore VPN, and then correlated upon instantiation of
the vCE on an end-system with the end-system IP address and the
appropriate VRF on that end-system. In addition, the vCE must be
configured with default routes per routing context with the next hop
being the vPE.
8.2.2 Co-located vCE-vPE connectivity with vPE Model 2
In this model, there is no control plane routing component
implemented on the end-system. That, is the end-system does not
generate VPN routes and only receives VPN FIB entries from the out-
of-band control plane component for routes reachable locally and for
remote routes. The vCE-control plane interaction is similar to that
of the interaction in Model 1 case 1-B described in the previous
section whereby route population is management-driven.
8. Security Considerations
vCE creation on server - is server owned by the the operator? is this
managed CE model? how to authenticate?
vCE in DC connecting VPN in WAN IP - are the DC and WAN IP VPN belong
to the same SP or different? How much info are permitted to pass
through auto-provisioning? How to authenticate connections,
especially in pull models?
How vCE protects itself from attach from client VMs?
Additional security procedures in all virtualized cloud/DC
environment, FW placement. All virtualized appliances need to be
protected against attack.
Three tier (Web, App, DB) interaction access control.
Details to be added.
9. IANA Considerations
None.
10. References
10.1 Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
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Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
Border Gateway Protocol 4 (BGP-4)", RFC 4271, January
2006.
[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, February 2006.
[RFC4560] Quittek, J., Ed., and K. White, Ed., "Definitions of
Managed Objects for Remote Ping, Traceroute, and Lookup
Operations", RFC 4560, June 2006.
[RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
"Multiprotocol Extensions for BGP-4", RFC 4760, January
2007.
[RFC5880] Katz, D. and D. Ward, "Bidirectional Forwarding Detection
(BFD)", RFC 5880, June 2010.
[I-D.ietf-l3vpn-end-system] Marques, P., Fang, L., Pan,
P., Shukla, A., Napierala, M., "BGP-signaled end-system
IP/VPNs", draft-ietf-l3vpn-end-system, work in progress.
[IEEE 802.1ad] IEEE, "Provider Bridges", 2005.
[IEEE 802.1q] IEEE, "802.1Q - Virtual LANs", 2006.
[IEEE 802.1ag] IEEE "802.1ag - Connectivity Fault
Management", 2007.
10.2 Informative References
[RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z.,
and W. Weiss, "An Architecture for Differentiated
Service", RFC 2475, December 1998.
[I-D.fang-l3vpn-virtual-pe] Fang, L., Ward, D., Fernando, R.,
Napierala, M., Bitar, N., Rao, D., Rijsman, B., So, N.,
"BGP IP VPN Virtual PE", draft-fang-l3vpn-virtual-pe, work
in progress.
[I-D.ward-irs-framework] Atlas, A., Nadeau, T., Ward. D., "Interface
to the Routing System Framework", draft-ward-irs-
framework, work in progress.
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[I-D.rfernando-irs-framework-requirement] Fernando, R., Medved, J.,
Ward, D., Atlas, A., Rijsman, B., "IRS Framework
Requirements", draft-rfernando-irs-framework-requirement-
00, work in progress.
[I-D.mahalingam-dutt-dcops-vxlan]: Mahalingam, M, Dutt, D.., et al.,
"A Framework for Overlaying Virtualized Layer 2 Networks
over Layer 3 Networks" draft-mahalingam-dutt-dcops-vxlan,
work in progress.
[I-D.sridharan-virtualization-nvgre]: SridharanNetwork, M., et al.,
"Virtualization using Generic Routing Encapsulation",
draft-sridharan-virtualization-nvgre,, work in progress.
11. Acknowledgement
The authors would like to thank Vaughn Suazo for his review and
comments.
Authors' Addresses
Luyuan Fang
Microsoft
5600 148th Ave NE
Redmond, WA 98052
US
Email: lufang@microsoft.com
John Evans
Cisco
16-18 Finsbury Circus
London, EC2M 7EB
UK
Email: joevans@cisco.com
David Ward
Cisco
170 W Tasman Dr
San Jose, CA 95134
US
Email: wardd@cisco.com
Rex Fernando
Cisco
170 W Tasman Dr
San Jose, CA
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US
Email: rex@cisco.com
Ning So
Vinci Systems
Email: ning.so@vinci-systems.com
Nabil Bitar
Verizon
40 Sylvan Road
Waltham, MA 02145
Email: nabil.bitar@verizon.com
Maria Napierala
AT&T
200 Laurel Avenue
Middletown, NJ 07748
Email: mnapierala@att.com
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